VULNERABILITY AS CAUSE OF SUBSTANCE ABUSE

This section contains some articles that discuss one of several Causes of Substance Abuse —vulnerability. In addition to an Overview article, the following topics are discussed as vulnerability factors: Gender; Genetics; the Psychoanalytic Perspective; Race; Sensation Seeking; Sexual and Physical Abuse; and Stress. For more information, see Comorbidity and Vulnerability, Families and Drug Use, and Poverty and Drug Use.

An Overview

There are marked individual differences in drug use and abuse. Some people never use drugs although drugs may be readily available to them. Others use drugs sporadically or regularly for years but never escalate their use to drug Dependence. Others become chronic, compulsive users and have difficulty functioning without drugs. These individual differences in drug-use patterns are the result of a combination of environmental and genetic factors. Environmental factors include the experiences of an individual, such as family and social conditions, as well as other conditions under which the person lives. Genetic factors refer to the genes that are passed down from parent to child and which are shared in part by other family members.

Environmental and genetic factors combine to produce risk factors, which are influences that increase the likelihood of drug use. They may also combine to produce protective factors, which are influences that decrease the likelihood of drug use. Vulnerability refers to the sum total of an individual's risk and protective factors. It defines the overall likelihood of drug use. Individuals with many risk factors and few protective factors are more likely than individuals with few risk factors and many protective factors to use drugs.

GOALS OF VULNERABILITY RESEARCH

In vulnerability research, attempts are made to identify risk and protective factors for both drug use and drug dependence, refine existing risk and protective factors by enhancing their specificity in predicting drug use, reduce the number of risk and protective factors to their most fundamental number, and understand the environmental and genetic influences (i.e., mechanisms) that underlie risk and protective factors.

Risk-Factor Identification.

A large number of risk factors for substance abuse have been reported (Table 1). They include characteristics that fall within the demographic, environmental, socio-cultural, family, personality, behavioral, psychiatric, and genetic domains. Among these are Poverty, unemployment, poor quality of education, racial discrimination, ready availability of drugs, family discord, family alcohol and drug use, sexual abuse, lack of family rituals, neuropsychological deficits, childhood aggressiveness, low self-esteem, teenage pregnancy, rebelliousness, delinquency, drug use by peers, mental health problems, and cultural alienation.

A number of protective factors for substance abuse have also been reported (Table 2); however, these are considerably fewer than the reported number of risk factors, primarily because less attention has been focused on their identification. In general, the protective factors that have been reported are the opposite of known risk factors. As such, they include an adequate income, high-quality schools, positive self-esteem, and the like.

Given the fact that a large number of risk factors are commonly present in modern society, many people possess multiple risk factors for drug use. Becoming a drug user is not an inevitable outcome for these people, however, since many individuals with multiple risk factors do not become drug users. Similarly, some individuals who are drug users or drug dependent have few risk factors.

Risk-Factor Specificity.

Unfortunately, many risk factors are so broadly defined that they are not useful as predictors. For example, we know that males are more likely than females to use illicit drugs and that underemployed people are more likely than employed people to become Heroin addicts. Being male or being underemployed, however, is not a useful predictor of drug use. Most males do not use illicit drugs and most underemployed people are not heroin addicts. Combining Gender and employment status into a single risk factor (i.e., the risk factor of being an underemployed male) increases specificity somewhat, and combining these factors with other risk factors (e.g., having an Antisocial Personality disorder) increases the predictive value even more.

The problem with lack of specificity is that it leads to overinclusion of people in risk groups. Many people are thus included in a risk group who are not actually at risk of becoming drug users. For example, although being male and being underemployed are factors statistically associated with heroin addiction, it is important to remember that this is only a statistical association. Most individuals with these characteristics never become heroin addicts. Thus, underemployed males represent a category that includes a large number of individuals who are not actually at risk for heroin addiction. Increasing specificity in risk factors is important because it allows the resources for Prevention to be directed toward the people in greatest need. Specificity also minimizes the problem of inappropriately stigmatizing people because they have a characteristic that is statistically associated with drug use.

Fundamental Risk Factors.

Because of their current lack of etiological specificity, concern has been expressed about the usefulness of the large number of risk factors that have been reported for drug use. Over seventy risk factors for drug use have been reported to date, but it is not clear if they are all independent factors. Some reported risk factors may be the product of other risk factors. For example, neuropsychological deficits may precipitate learning problems, which in turn may lead to excessive Childhood aggressiveness. Similarly, family alcohol and drug use may result in family discord, and poor-quality schools may contribute both to underemployment and Homelessness.

Other risk factors may reflect different manifestations of more basic factors. For example, rebelliousness, Delinquency, and aggressiveness may reflect a more basic personality characteristic or be the result of common genetic influences. Although the actual number of basic risk factors in drug use is not known, they are certain to be fewer than the large number of risk factors reported to date. The large number of reported risk factors probably reflects the highly interrelated nature of the influences involved in drug use.

Underlying-mechanism Identification.

A risk factor may itself be a product of the interaction among environmental and genetic influences, or it may only be correlated with those influences. In either case, it is useful for predicting drug use. To most efficiently prevent drug use, however, it is necessary to understand the basic mechanisms that control drug use. As one increases the specificity of risk factors and reduces them to their most fundamental number, one comes ever closer to identifying the specific environmental and genetic mechanisms involved.

At present, most risk factors are hypothetical constructs and only conceptually defined. Consequently, the risk factor does not identify the mechanisms responsible for drug use. To understand how the risk factor increases the likelihood of drug use, one must identify the mechanisms involved. For example, having drug-using peers is recognized as a risk factor for drug use (because drug use by Adolescents is frequently associated with having drug-using peers). Although the specific mechanisms mediating this influence are not definitely known, it is likely that the influence is mediated in part through drug-using peers increasing drug availability and providing social reinforcement for drug use. Similarly, coming from an impoverished environment is thought to be a risk factor for drug use because it fails to provide reinforcers as an alternative to drug use.

Genetic influences may also underlie many risk factors for both drug use and dependence. These influences may contribute to drug use through personality characteristics (e.g., Sensation Seeking, risk taking) that increases the likelihood of drug use and that may be genetically determined. Genetic influences may also contribute to the development of drug dependence by altering the effects of a drug (e.g., causing greater euphoria in some people than in others). In addition, they may contribute to both drug use and dependence by being responsible for the absence of normal protective factors (e.g., failure to experience a hangover after excessive alcohol use). The specific genetic mechanisms involved will be the genes (as yet unidentified) that contribute to personality development, drug response, and other important components.

The specific mechanisms that control drug use are undoubtedly the same environmental and genetic mechanisms that control human behavior in general. The mechanisms responsible for the initial drug use and for the progression to regular use and possibly drug dependence may not be the same. Once these mechanisms are understood, however, it will be possible to more directly address risk factors for drug use by means of intervention measures. The ultimate goal of those engaged in vulnerability research is to develop efficient, cost-effective prevention programs that specifically target individuals at risk for both drug use and drug dependence.

VULNERABILITY RESEARCH STRATEGIES

A variety of strategies are available for achieving the goals of vulnerability research. They include both epidemiological and experimental studies, genetic studies, and Animal Research.

Cross-sectional Epidemiological Studies.

Risk factors are initially identified through their statistical association with drug use. Most of the risk and protective factors reported to date have been identified by comparing drug abusers and controls on the basis of currently existing characteristics or reports of conditions existing prior to onset of drug use. For example, individuals are divided into drug users and non-drug users on the basis of a survey, and compared as to demographic characteristics and other traits. The factors that distinguish the drug users from the non-drug users are then identified as risk factors for drug use.

This strategy permits the inexpensive identification of a large number of possible risk factors for drug use. The ability of the strategy to detect possible risk factors is limited only by the selection of characteristics to be compared. With this strategy, however, it is sometimes not clear if a characteristic existed prior to onset of drug use or developed as a consequence of drug use. Since, moreover, the reports of the preexisting conditions are often based on retrospective recall, people's memory problems as well as their attempts to justify their drug use may confound the accuracy of the self-reports. Finally, inappropriate control groups are sometimes employed whose subjects differ from drug users in important aspects (e.g., demographic and clinical features), and this confounds the research design.

Longitudinal Epidemiological Studies.

A better research method for identifying risk and protective factors in drug use is the longitudinal study design. With this design, individuals are assessed for various characteristics prior to the age of risk for drug abuse and then followed over time to determine those who do and those who do not become drug users. After drug users have been identified, earlier characteristics that distinguished them from nonusers can be determined.

The advantages of this method are that the drug users and nonusers are drawn from the same population and therefore constitute appropriate comparison groups. Furthermore, because the study design is prospective, it does not rely on the retrospective recall of events or conditions that might have existed prior to the onset of drug use and therefore might be confounded by incorrect memory or other problems. Finally, because this design provides for initial assessment of the subjects prior to the onset of drug use, preexisting conditions can be separated from the consequences of drug use. This design has not been widely employed, however, owing to the expense and time required to conduct the studies. There is also the problem of sample bias that might occur as a result of the attrition of subjects. For example, drug users with severe dependence or psychiatric disorders might be lost in the longitudinal follow-up process, thus leaving only the less severe drug users in the subject sample.

In general, both cross-sectional and longitudinal epidemiological strategies are useful in identifying risk factors for drug use and dependence. They are also both useful in increasing the predictive specificity of risk factors and in allowing fundamental features of various risk factors to be identified by use of sophisticated statistical modeling.

One problem that may affect both types of epidemiological studies is the failure to define risk factors operationally or objectively. This occurs less often when the risk factor involves direct measurement of the individual or use of standardized tests than when individuals are asked about a trait and no definition or operational criteria for the trait is given. For example, if subjects are asked to report on their current level of self-esteem (i.e., whether it is low, medium, or high), failure to define the concept operationally may cause confusion over its presence or absence in a given individual, and this confusion will also increase its variability across individuals.

Experimental Laboratory Studies.

This strategy (termed the high-risk design) is aimed at determining the mechanism by which risk factors exert their effects. It compares two groups of individuals who are distinguished by the presence or absence of a particular risk factor. For example, the two groups might consist of children of substance abusers and children of non-substance abusers, or individuals who are depressed and individuals who are not depressed. The two groups are then compared on the basis of various dependent measures, which may include baseline characteristics (e.g., personality) or response to experimental manipulations (e.g., reaction to stress). If the two groups respond differently on a dependent measure, this suggests that the measure is a possible mechanism by which the trait is related to drug use.

This strategy has several advantages. Because it entails selecting subjects on the basis of a specific characteristic, it affords a high degree of control over extraneous factors that might confound the interpretation of epidemiological studies. It also allows researchers to measure subjects' responses directly under standard environmental conditions, rather than relying on self-reports of past events. In addition, it permits the experimental manipulation of test conditions, which in turn allows the generality of an observed effect to be determined. It also enhances the probability that the observed effect is due to the experimental manipulation. Finally, it permits mechanisms underlying the risk factors to be identified and explored, a process that can only be assessed correlationally through statistical modeling in epidemiological studies.

In contrast to epidemiological strategies, however, the high-risk strategy can only address one risk factor per study. It is further restricted by the appropriateness of criteria used for subject selection and the experimental measures employed. For example, inappropriate subject inclusion criteria may exclude the subjects at risk, or inappropriate response measures may fail to detect group differences that are present. Laboratory studies also typically employ only a relatively small number of subjects. This small number increases the likelihood that a biased sample will result, thus making for reduced generalizability of the findings.

Genetic Studies.

A number of strategies are available to determine if genetic influences are involved in drug use and dependence. Family studies determine if drug use or dependence "run in families." If higher rates of drug use are found in the relatives of drug users than in the relatives of non-drug users, then genetic influences may be involved. To separate the effects of genes and environment, however, requires doing adoption or twin studies. In adoption studies, evidence of genetic influences is provided by adoptees having higher rates of drug use if their biological parents were drug users than if their biological parents were not drug users. In twin studies, since identical (monozygotic) twins have more of their genes in common than do fraternal (dizygotic) twins, evidence of genetic influence is suggested by higher concordance rates for drug use or dependence in identical than in fraternal twins.

Other types of genetic strategies are also available. The purpose of linkage and association studies is to identify specific genes involved in drug use and dependence. In linkage studies, different generations of Families are examined to determine if a genetic marker is inherited along with a disorder (e.g., substance abuse). In association studies, individuals with and without a disorder are compared to determine the association of the disorder with a genetic marker. The previously described high-risk study designs are frequently employed in genetic research. In these studies, subjects who are not yet substance abusers are typically divided into two groups on the basis of their known risk for substance abuse (e.g., having or not having a family history of substance abuse). The two groups are then compared to identify factors that may contribute to their differences in risk for substance abuse.

Most of these genetic strategies have the same strengths and limitations previously described in regard to epidemiological and experimental laboratory studies. In addition, twin and adoption studies are based on certain assumptions about the nature of the genetic influence and parental mating characteristics that may affect interpretation of the results.

Animal Studies.

Certain factors contributing to drug use and dependence can be studied experimentally only in animals. For example, it would be unethical to make a human being dependent on drugs in order to study the process of becoming drug dependent. In animals, this process can be brought under experimental control and studied directly. In human beings, drug use or dependence typically becomes evident to researchers only after it has occurred, and then the process can be studied only retrospectively.

A number of strategies are available for studying drug taking by animals. The most common of these are the animal drug self-administration methods. With these methods, animals are equipped with small tubes (catheters) that run directly from the animal's bloodstream to an injection pump located outside the cage. By pressing a lever, the animal automatically activates the injection pump and receives a predetermined amount of drug solution injected directly into the bloodstream. Similar methods are available to study self-administration of drugs by other routes. By means of these methods, it has been found that animals self-administer essentially the same drugs that humans abuse, and this has resulted in the methods being used to predict the abuse potential of new drugs before they are marketed. Keeping drugs with high dependence potential off the market is also an effective strategy for reducing people's vulnerability to drug use and dependence.

Animal drug self-administration methods can also be used to study factors that contribute to a person's acquiring the problem of drug use and dependence. With these methods, factors thought to influence vulnerability can be experimentally manipulated and studied under controlled laboratory conditions. As a result of the research, a large number of factors have been identified with animal drug self-administration methods that are relevant to the development of human drug dependence. Among these are the reinforcing property of the drug itself, the speed with which a drug is injected, the schedule of drug delivery, the availability of other reinforcers, and the aversiveness of the environment. The knowledge gained from the research can be applied directly to human drug abuse prevention efforts.

Animal methods make possible the experimental study of factors that influence the acquiring of the habit of drug use and dependence, a process that cannot be ethically studied with human beings. Animals, however, differ from human beings in many ways that may be important in the etiology of drug abuse, and therefore care must be taken in generalizing the results of animal studies to human beings. In addition, although animal models provide an excellent way of studying behavioral and environmental factors in drug use, the approach cannot readily be used to study other risk factors (i.e., psychosocial and cultural influences) that are believed to be important in the development of drug abuse by human beings.

(See also: Abuse Liability of Drugs: Testing in Animals ; Addiction: Concepts and Definitions ; Adjunctive Drug Taking ; Complications: Mental Disorders ; Conduct Disorder and Drug Use ; Disease Concept of Alcoholism and Drug Abuse ; Epidemiology of Drug Abuse ; Ethnicity and Drugs ; Research, Animal Model ; Wikler's Pharmacologic Theory of Drug Addiction )

BIBLIOGRAPHY

Glantz, M., & Pickens, R. (1992). Vulnerability to drug abuse. Washington, DC: American Psychological As sociation.

Hawkins, J.D., Catalano, R. F., & Miller, J.Y. (1992). Risk and protective factors for alcohol and other drug problems in adolesence and early adult hood: Implications for substance abuse prevention. Psychological Bulletin, 112, 64-105.

Kahn, H. A., & Sempos, C. T. (1989). Statistical methods in epidemiology. New York: Oxford University Press.

Office of Substance Abuse Prevention. (1991). Breaking new ground for youth at risk: Program summaries. OSAP Technical Report 1, DHHS Publication No. (ADM) 91-1658. Washington, DC: U.S. Government Printing Office.

Roy W. Pickens

Dace S. Svikis

Gender

Apart from the use of Tobacco (cigarettes) and Psychoactive Drugs, men show a consistently higher rate of drug use than do Women, especially with reference to Alcohol and to Marijuana and other illicit drugs (Substance Abuse and Mental Health Services Administration, 1992; Anthony, 1991; Robins et al., 1984; Kandel & Yamaguchi, 1985; Windle, 1990; Robbins, 1989). Women are more likely than men to use the drugs prescribed by a physician, especially psychotrophic drugs (Cafferata et al., 1983), and although men still have a higher rate of Cigarette use, this difference is decreasing (Kandel & Yamaguchi, 1985; National Institute on Drug Abuse, 1989 & 1991; SAMSA, 1992).

Gender differentiation in society occurs at many levels and in the major institutions such as government, family, the economy, education, and religion, as well as in face-to-face interpersonal interaction (Giele, 1988). It is therefore not surprising that drug use behavior differs for men and women. Because of the pervasive way in which gender roles affect most aspects of people's lives, it remains a complex task to understand gender differences in patterns of drug use. It is expected that gender will influence patterns of substance use and consequences of substance abuse, in part because men and women are socialized according to different behavior patterns and values. Normative expectations for men include self-reliance and physical effectiveness. By contrast, women are taught to value close relationships and to define themselves in terms of those relationships. With regard to substance use, the literature shows that gender (a) is associated with use of alcohol and drugs; (b) is associated with a variety of psychosocial characteristics that are themselves associated with alcohol and drug use; (c) and may be associated with different etiologies of alcohol and drug use—and with different consequences of substance use and treatment outcomes. The role of gender in drug use has been demonstrated in a number of studies conducted in the United States; several of these have provided comprehensive comparisons of the psychological, social, and biological characteristics of male and female drug users (Kaplan & Johnson, 1992; Lex, 1991; Gomberg, 1986; Ray and Braude, 1986).

According to the convergence hypothesis, the increasing similarity of roles and activities of men and women, as illustrated by the increasing participation of women in the paid labor force, will result in the drug and alcohol behaviors of women increasingly approximating those of men (see Adler, 1975; Bell, 1980). Although there is some evidence that male and female Adolescents have similar drug-use behaviors, recent epidemiological data indicate that alcohol and drug problems are still more common among men than among women (Anthony, 1991). Lennon (1987) found no support for the hypothesis that women in "male" jobs resembled men in terms of their levels of drinking. In the case of cigarettes, the increasing similarity of men's and women's behavior has been the result of both women increasing and men decreasing their use of cigarettes. There is little evidence to support the theory of increasing convergence of substance use, although it should be noted that many of the early studies of alcohol or drug use included only men, so that little is known about trends in women's use (Robins & Smith, 1980; see Vannicelli & Nash [1984] for an analysis of sex bias in alcohol studies).

The various perspectives that can be used to explain gender differences in drug and alcohol use include: (1) gender role explanations; (2) the social control theory; and (3) biological explanations. Explanations that draw on gender role theories to explain male-female differences refer to normative expectations and rules regarding the behavior of males and females. According to one hypothesis, there are distinctive gender styles in expressing pathology (Dohrenwend & Dohrenwend, 1976). The male style features acting-out behaviors (including drug and alcohol use), whereas the female style involves the internalization of distress. A finding consistent with this hypothesis was that of several researchers, who observed that for females, conformity to the female identity was related to higher psychological distress and lower substance use than was observed in males (Horowitz & White, 1987; Huselid & Cooper, 1992; Snell, Belk, & Hawkins, 1987; Koch-Hattem & Denman, 1987). The evidence for males has been inconsistent, however. Although there was more alcohol and drug use among males than among females, ascribing to the conventional masculine role did not necessarily lead to more alcohol or drug problems for males.

A second explanation for gender differences in alcohol and drug use is that societal expectations differ for men and women, with the result that using illicit substances for pleasure is more acceptable in men than it is in women (Landrine, Bardwell, & Dean, 1988; Lemle & Mishkind, 1989; Gomberg, 1986). Women are more likely to use substances for therapeutic reasons, specifically for the relief of mental and physical distress, whereas men are more likely to use drugs for recreation. Surveys in which it was found that men use more illicit drugs, primarily for recreation, and women use more psychotherapeutic drugs have borne out this theory.

A closely related hypothesis that is particularly relevant to the higher use of psychotropic drugs by women is that society permits women to perceive more illness (morbidity) and to use more medical care than it does men, who are expected to be stoic in the face of illness. Survey results seem to confirm the behavioral differences suggested by this hypothesis. In a review of morbidity and mortality studies, Verbrugge (1985) found that women consulted physicians more often than men, assumed the patient's role more readily, and appeared to take better care of themselves in general. These behaviors would make women more inclined than men to use prescription drugs and less inclined to use other drugs. The increasing use of cigarettes by younger women, however, is one behavior that runs counter to this hypothesis.

According to the social control theory, those who have strong ties to societal institutions such as family, school, or work are less likely to have a problem with use of substances. This perspective stems from Emile Durkheim's classic study of Suicide (1898). Umberson (1987) applied Durkheim's perspective to health behaviors and showed that social ties affect the health behaviors of individuals (e.g., physical activity, alcohol consumption, compliance with doctor's recommendations, etc.) and that consequently they affect health status and mortality rates. Social ties, according to this argument, affect drug use behaviors in two ways. First, there is an increased likelihood that the behavior of those with strong social ties will be monitored by family members and friends, and this would tend to decrease use of illicit or unhealthy substances. Second, the responsibility and obligation entailed in an individual sharing strong ties and frequent activities with family and friends make for more self-regulation of behavior. Marriage and being a parent represent important social ties that may affect people's use of substances, especially in the case of women, because of their traditional roles in nurturing and maintaining family relationships.

Several studies have shown the increased vulnerability to drug use of women in relation to social ties. Kaplan and Johnson (1992) showed that the attenuation of interpersonal ties resulting from initial drug use caused women, but not men, to increase their drug use. Similarly, Kandel (1984) reported that interpersonal factors were more significant for women than for men in explaining marijuana use. Ensminger, Brown, and Kellam (1982) showed that strong family bonds inhibited drug use in female adolescents but not in male adolescents.

Physiological differences may also be important in accounting for gender differences in patterns of substance use. Mello has (1986) suggested that a woman's use of drugs and alcohol may be influenced by menstrual cycle phases (Mello, 1986), although little evidence exists for this hypothesis. Halbreich et al. (1982) examined the scores on the Premenstrual Assessment Form and found that women who increased their marijuana use at the premenstruum reported significantly greater Depression, Anxiety, mood changes, anger, and impaired social functioning than did women whose marijuana use decreased or stayed the same.

The relatively low rate of consumption of drugs by women may be related to biological differences in the ways drugs are cleared from the body in women versus men. The lower ratio of water to total body weight in women causes them to metabolize alcohol and drugs differently (Mello, 1986; Straus, 1984). This and other biological factors may cause women to have higher Blood-Alcohol Concentrations (BACs) than men at equal dosages (Corrigan, 1985; McCrady, 1988). Drugs that are deposited in body fat, such as marijuana, may be slower to clear in women than in men because of the higher ratio of fat in women (Braude & Ludford, 1984).

Gender roles are the major roles in human society, and they influence almost every aspect of an individual's life. Despite the evidence for gender differences in patterns of drug use, little attention has been given either to the potential strategic advantages that this observation presents for furthering our understanding of drug and alcohol use patterns in males and females, or for determining how prevention and treatment programs might be redesigned.

(See also: Comorbidity and Vulnerability ; Conduct Disorder and Drug Use ; Epidemiology ; Gender and Complications of Substance Abuse )

BIBLIOGRAPHY

Adler, F. (1975). Sisters in crime. Prospect Heights, IL: Woreland.

Anthony, J. C. (1991). The epidemiology of drug addiction. In N. S. Miller (Ed.), Comprehensive handbook of drug and alcohol addiction. New York: Marcel Dekker.

Bell, D. S. (1980). Dependence on psychotropic drugs and analgesics in men and women. In O. J. Kalant (Ed.), Alcohol and drug problems in women. New York: Plenum.

Braude, M. C., & Ludford, J. P. (1984). Marijuana effects on the endocrine and reproductive systems: Araus review report (NIDA Research Monograph 44). Rockville, MD: National Institute on Drug Abuse.

Cafferata, G. L., Kasper, J., & Bernstein, A. (1983, June). Family roles, structure, and stressors in relation to sex differences in obtaining psychotropic drugs. Journal of Health and Social Behavior, 24, 132-143.

Corrigan, E. M. (1985). Gender differences in alcohol and other drug use. Addictive Behaviors, 10, 313-317.

Dohrenwend, B. P., & Dohrenwend, B. S. (1976). Sex differences in psychiatric disorders. American Journal of Sociology, 81, 1447-1454.

Durkheim, E. (1898). Suicide: A study in sociology. (J. A. Spaulding & G. Simpson, trans.). New York: Free Press.

Ensminger, M. E., Brown, C. H., & Kellam, S.G. (1982). Sex differences in antecedents of substance use among adolescents. Journal of Social Issues, 38 (2), 25-42.

Giele, J. Z. (1988). Gender and sex roles. In N. J. Smelser (Ed.), Handbook of sociology. Newbury Park, CA: Sage Publications.

Gomberg, E. S. L. (1986). Women: Alcohol and other drugs. In Drugs and society. Binghamton, NY: Haworth Press.

Halbreich, U., Endicott, J., Schacht, S., & Nee, J. (1982). The diversity of premenstrual changes as reflected in the Premenstrual Assessment Form. Acta Psychiatrica, 65, 46-65.

Horowitz, A.V., &White, H. R. (1987, June). Gender role orientations and styles of pathology among adolescents.Journal of Health and Social Behavior, 28, 158-170.

Huselid, R. F., & Cooper, M. L. (1992). Gender roles as mediators of sex differences in adolescent alcohol use and abuse. Journal of Health and Social Behavior, 33, 348-362.

Kandel, D. B. (1984). Marijuana users in young adulthood. Archives of General Psychiatry, 41, 200-209.

Kandel, D. B., & Yamaguchi, K. (1985). Developmental patterns of the use of legal, illegal, and medically prescribed psychotropic drugs from adolescence to young adulthood. In Etiology of drug abuse: Implications for prevention (NIDA Research Monograph Series No. 56, DHHS Publication No. ADH 85-1335). Washington, DC: U.S. Government Printing Office.

Kaplan, H. B., & Johnson, R. J. (1992). Relationships between circumstances surrounding initial illicit drug use and escalation of drug use: Moderating effects of gender and early adolescent experiences. In M. Glantz & R. Pickens (Eds.), Vulnerability to drug abuse. Washington, DC: American Psychological Association.

Koch-Hattem, A., & Denman, D. (1987). Factors associated with young adult alcohol abuse. Alcohol and Alcoholism, 22, 181-192.

Landrine, H., Bardwell, S., & Dean, T. (1988). Gender expectations for alcohol use: A study of the significance of the masculine role. Sex Roles, 19, 703-712.

Lemle, R., & Mishkind, M. E. (1989). Alcohol and masculinity. Journal of Substance Abuse Treatment, 6, 213-222.

Lennon, M. C. (1987). Sex differences in distress: The impact of gender and work roles. Journal of Health and Social Behavior, 28, 290-305.

Lex, B. W. (1991). Gender differences and substance abuse. In N. K. Mello (Ed.), Advances in substance abuse (Vol. 4). London: Jessica Kingsley.

Mc Crady, B. S. (1988). Alcoholism. In E. A. Blechman & K. O. Brownell (Eds.), Handbook of behavioral medicine for women. New York: Pergamon.

National Institute on Drug Abuse. (1991). National Household Survey on Drug Abuse: Main Findings 1990. Washington, DC: U.S. Department of Health and Human Services, Public Service, Alcohol, Drug Abuse, and Mental Health Administration.

National Institute on Drug Abuse. (1989). National Household Survey on Drug Abuse: Highlights 1988. Washington, DC: U.S. Department of Health and Human Services, Public Service, Alcohol, Drug Abuse, and Mental Health Administration.

Ray, B. A., & Braude, M.C. (Eds.). (1986). Women and drugs: A new era for research (NIDA Research Monograph No. 65, DHHS Publication No. ADM 86-1447). Washington, DC: U.S. Government Printing Office.

Robbins, C. (1989, March). Sex differences in psychosocial consequences of alcohol and drug abuse. Journal of Health and Social Behavior, 30, 117-130.

Robins, L.N., & Smith, E. M. (1980). Longitudinal studies of alcohol and drug problems: Sex differences. In O. J. Kalant (Ed.), Alcohol and drug problems in women: Research advances in alcohol and drug problems (Vol. 5). New York: Plenum.

Robins, L. N., etal. (1984). Lifetime prevalence of specific psychiatric disorder in three sites. Archives of General Psychiatry, 41, 929-958.

Snell, W. E., Jr., Belk, S. S., & Hawkins, R. C., II. (1987). Alcohol and drug use in stressful times: The influence of the masculine role and sex-related personality attributes. Sex Roles, 16, 359-373.

Straus, R. (1984). The need to drink too much. Journal of Drug Issues, 14, 125-136.

Substance Abuse and Mental Health Services Administration. (1993). National Household Survey on Drug Abuse: Population estimates 1992. Washington, DC: U.S. Department of Health and Human Services, Public Health Service.

Umberson, D. (1987). Family status and health behaviors: Social control as a dimension of social integration. Journal of Health and Social Behavior, 28, 306-319.

Vannicelli, M., & Nash, L. (1984). Effect of sex bias on women's studies on alcoholism. Alcohol Clinical and Experimental Research, 8, 334-336.

Verbrugge, L. M. (1985, September). Gender and health: An update on hypotheses and evidence. Journal of Health and Social Behavior, 26, 156-182.

Windle, M. (1990). A longitudinal study of antisocial behaviors in early adolescence as predictors of late adolescence substance use: Gender and ethnic group differences. Journal of Abnormal Psychology, 99 (1), 86-91.

Margaret E. Ensminger

Jennean Everett

Genetics

Genes are passed from parent to child in the process of sexual reproduction. These genes determine some of the features of the individual and contribute directly and indirectly to many more. The possibility of genetic influences in substance abuse has received considerable attention. Evidence that genetic influences may be involved comes from family studies, where substance abuse has been found to run in families. For example, alcoholics have been found to have more relatives who are alcoholic than would be expected from the base rate for Alcoholism in the general population. Similarly, higher rates of Heroin and Cocaine abuse are also seen in the relatives of heroin and cocaine abusers than occur in the general population.

Both twin and family studies have been conducted to separate genetic from environmental influences in the familial transmission of substance abuse. Most of the research has involved Alcohol. There is general agreement that genetic influences are involved in both alcohol use and alcoholism, at least for males. Twin studies of males from the general population have found that if one pair member drinks alcohol, the other pair member is more likely to drink (i.e., they are concordant for this behavior) if the two members shared all the same genes (if they are monozygotic or identical twins) than if they share only about half of their genes (if they are dizygotic or fraternal twins). Similar studies on clinical patients have found higher concordance for alcoholism among men who are monozygotic rather than dizygotic twins. Adoption studies have found that sons of alcoholic biological parents were more likely to be alcoholic as adults than sons of nonalcoholic biological parents, when both groups were adopted out early in life and raised by nonalcoholic adoptive parents. Among men, estimates of the proportion of variance in alcohol-dependence liability due to genetic influences (i.e., heritability) range from 0.50 to 0.60, depending on the subject population and sub-type of alcoholism.

For women, the role of genetic factors in alcohol use and alcoholism is less convincing. This is primarily because women have been studied less often than men and in smaller numbers. One reason for this discrepancy is that women are less likely to have alcohol problems, and this fact itself may reflect the greater role of nongenetic influences for women. In twin and adoption studies involving women, evidence of genetic influence has been found less consistently than has been found for men, with heritabilities for women ranging from 0.00 to 0.56. depending on the study. Nevertheless, women have similar percentages of same- and opposite-sex alcoholic relatives as do men, and this suggests that there is no differential heritability related to gender.

Although less frequently studied, genetic influences for other forms of drug use and dependence have also been shown, but only males have typically been studied in this context. Heritabilities reported for tobacco smoking range from 0.28 to 0.84 and are not affected by other factors that may contribute to differences in concordance rates in twins. Heritabilities reported for other types of illicit drug use (but not necessarily drug dependence) range from 0.4 to 0.6. Heritability for any substance abuse or dependence (excluding alcohol and tobacco) in alcoholic probands is 0.31.

Linkage and association studies permit the identification of specific genes involved in substance abuse. In linkage studies, different generations of families are examined to determine if a genetic marker is inherited along with a disorder (e.g., substance abuse). In association studies, individuals with and without a disorder are compared to determine the association of the disorder with a genetic marker. To date, no specific gene for alcoholism or for other types of drug dependence has been identified.

Animal models have also been employed to study genetic influences in substance abuse. Evidence of significant genetic influence has been found in the characteristics of many drug responses relevant to drug abuse (e.g., drug preference), and chromosomal loci have been identified that mediate at least some of these effects. To the extent that the genetic structure of mice is similar to that of human beings, the findings derived from animal models suggest testable hypotheses to be explored in human-association studies. In strains of rats that were bred in laboratories to study their preference for alcohol, the strain that developed a strong preference for alcohol had lower brain levels of the Neurotransmitter serotonin compared to the strain that did not prefer alcohol. This is of interest because alterations in Serotonin neurotransmission have also been noted in studies of impulsive aggressive human males (who have a higher likelihood of developing alcohol or drug problems) compared to human males without those behaviorial traits.

(See also: Attention Deficit Disorder ; Causes of Substance Abuse ; Conduct Disorder and Drug Use ;Disease Concept of Alcoholism and Drug Addiction ; Epidemiology of Drug Abuse )

BIBLIOGRAPHY

Glantz, M., & Pickens, R. (1992). Vulnerability to drug abuse. Washington, DC: American Psychological Association.

Hawkins, J.D., Catalano, R. F., & Miller, J.Y. (1992). Risk and protective factors for alcohol and other drug problems in adolesence and early adulthood: Implications for substance abuse prevention. Psychological Bulletin, 112, 64-105.

Kahn, H. A., & Sempos, C. T. (1989). Statistical methods in epidemiology. New York: Oxford University Press.

Office of Substance Abuse Prevention. (1991). Breaking new ground for youth at risk: Program summaries. DHHS Publication No. (ADM) 91-1658. Washington, DC: U.S. Government Printing Office.

Dace S. Svikis

Roy W. Pickens

Psychoanalytic Perspective

Increased vulnerability to Alcohol and drugs is related to the coming together of a number of influences, each of which is itself of varying strength. Our biologies, our individual social and cultural settings and backgrounds, our personal idiosyncratic life experiences, and the persons we become as a result of all these may contribute to the likelihood of our using drugs—and then of our continuing to use them. We are neither vulnerable nor invulnerable to using drugs or alcohol, nor to using them to excess; vulnerability is a continuum, ranging from least to most vulnerable. Under the right, or the wrong, circumstances, many of us will use drugs.

Alcoholism runs in families; if an individual's parent, grandparent, or sibling is alcoholic, that individual's own risk is significantly increased. It seems certain that an important contributor to this in many families is Genetic. While we find a similar increase in the frequency of substance abuse in the children of parents who use all sorts of drugs, we do not yet have evidence that this too is genetic. Certainly, another contributor to this familial pattern is the exposure that a developing child has to the sight and experience of a parent or other important figure in the environment using alcohol and/or other drugs. It tells the child that this is acceptable behavior, particularly if the surrounding social culture echoes that opinion. Cultures and subcultures that traditionally control drinking generally produce people who drink in a controlled way; cultures and subcultures that condone excess also reproduce themselves.

It is important to remember, however, that even those with a strong genetic loading for alcoholism can only become a "practicing" alcoholic if they have alcohol available. Despite its many problems, Prohibition (1920-1933) reduced the number of alcoholics; successful interdiction of drugs would reduce the number of substance abusers. However, growing up in an area where drugs are freely available increases the likelihood of trying them and—assuming community complacence or peer approval and encouragement—of continuing to take them. For example, during the war in Vietnam, many U.S. soldiers who had not been Opiate addicts found themselves in the war zone, exposed to Stress and personal danger, and surrounded by cheap available Heroin in a context that condoned its use. Many became addicted. On their return home, however, almost all gave up their drug use with relative ease.

We also know that the person one is—the kind of personality one has—also plays a role in one's susceptibility to using and misusing drugs. A number of studies suggest that maladjustment precedes the use of illicit drugs; the closer one is in style to an Eagle Boy Scout, the less likely one is to use drugs. Rebelliousness, stress on independence, apathy, pessimism, Depression, low self-esteem, and low academic aspirations and motivation make the use of illicit drugs more likely. Delinquent and deviant behavior come before the drug use; they are not the result of it.

(See also: Causes of Substance Abuse: Psychological (Psychoanalytic) Perspective ; Conduct Disorder and Drug Use ; Families and Drug Use ; Religion and Drug Use )

BIBLIOGRAPHY

Bohman, M., Sigvardsson, S., & Cloninger, C.R. (1981). Maternal inheritance of alcohol abuse. Archives of General Psychiatry, 38, 965-969.

Chein, I., etal. (1964). The road to H: Narcotics, delinquency, and social policy. New York: Basic Books.

Cloninger, C. R., Bohman, M., & Sigvardsson, S. (1981). Inheritance of alcohol abuse. Archives of General Psychiatry, 38, 861-868.

William A. Frosch

Race

Despite reservations about the use of race and ethnicity in health research (e.g., Bhopal & Donaldson, 1998; LaVeist, 1994; Williams et al., 1994), this variable remains one of the most often reported socio-demographic characteristics in drug abuse/dependence studies.

Data from the Monitoring the Future Study (Johnston, O'Malley & Bachman, 1996) and the Youth Risk Behavior Survey (Centers for Disease Control, 1995) are consistent in showing that black adolescents are less likely to use most drugs than their white and Hispanic counterparts. The National Household Survey on Drug Abuse, which includes adult participants and adolescents who are not in school, shows that after the age of 25 years, African Americans report more illicit drug use than Whites (SAMHSA, 1999). In 1998, among persons 35 years and older, 4.8 percent of blacks versus 3.2 percent of whites had used an illicit drug in the past month, and 1.3 percent versus 0.3 percent had used cocaine, respectively. Blacks had lower rates of past month alcohol use, "binge" drinking, and heavy alcohol use than whites and Hispanics (SAMHSA, 1998).

Data from other large-scale surveys have been used to estimate drug use and dependence in different groups. The Epidemiologic Catchment Area (ECA) Study, a prospective study of drug dependence in the United States, show that black youth are less likely than white youth to initiate licit and illicit drug use (Helzer, Burnam & McEvoy, 1991). This is reflected in the rate of lifetime alcoholism among black males in the 18 to 29 age group when compared to whites, 12.7 percent versus 28.3 percent. With increase in age, rates for blacks exceed those of whites and Hispanics until at 65 and over, blacks are nearly twice as likely as whites to be alcohol dependent. The ECA data also show that young Hispanic men have about the same level of risk of developing alcoholism as Whites.

In a separate analysis of data from the ECA, Anthony & Helzer (1991) found that the rate of illicit drug use for Hispanic men was much lower that those for blacks and whites, with the lowest rate among Hispanic women. Overall, white men had the highest rate of illicit drug use compared to the other two groups, with the most prominent difference seen in the 18 to 29 age group. The lifetime prevalence of drug dependence followed the pattern of drug use in the three groups, but there were few differences in the rates for active dependence.

Another major source of estimates on racial/ethnic differences in drug use and dependence is the National Comorbidity Survey. Data from the NCS agree with estimates from the other household surveys. Blacks and Hispanic are less likely to use drugs than Whites but Blacks do not differ from Whites in the probability of becoming dependent on drugs. What distinguishes the groups is persistence in drug dependence once the problem has started (Kessler et al., 1995). Blacks are 3 times and Hispanics 2.4 times more likely to report past year dependence on drugs than their white counterparts. In other words, while African Americans are less likely to initiate drug use and equally likely to become dependent, they are more likely than Whites to remain dependent.

There is growing evidence that these racial/ethnic differences in drug use and drug dependence are not due to innate racial differences. For example, Crum and Anthony (2000) have shown that, when socio-economic factors (e.g., poverty and neighborhood characteristics) are taken into consideration, race/ethnicity becomes and insignificant influence. Other factors that may help account for observed racial/ethnic differences in the vulnerability to drug use and dependence are dropping out of school (Obot & Anthony, 2000), opportunity to use illegal drugs (SAMHSA, 1998), and perception of risks associated with drug use (Ma & Shive, 2000).

BIBLIOGRAPHY

Anthony, J. C., & Helzer, J. E. (1991). Syndromes of drug abuse and dependence. In L.N. Robins & D.A. Regier (eds.), Psychiatric disorders in America: the Epidemiologic Catchment Area Study (pp. 116-154). New York: The Free Press.

Bhopal, R.&Donaldson, L. (1998). White, European, Western, Caucasian, or What? Inappropriate labeling in research on race, ethnicity, and health. American Journal of Public Health, 88 (9), 1303-1307.

Centers for Disease Control and Prevention (1995). Youth Risk Behavior Survey, 1995. Atlanta: CDC.

Crum, R. M., & Anthony, J. C. (2000). Educational level and risk for alcohol abuse and dependence: differences by race-ethnicity. Ethnicity and Disease, 10 (1), 39-52.

Helzer, J.E. &Burnam, A., & Mcelvoy, L. T. (1991). Alcohol abuse and dependence. In L.N. Robins & D.A. Regier (eds.), Psychiatric disorders in America: the Epidemiologic Catchment Area Study (pp. 81-115). New York: The Free Press.

Johnston, L. D., O'Malley, P. M., & Bachman, J.G. (1996). National survey results on drug use from the Monitoring the Future Survey, 1975-1995. Vol.1. Secondary school students. Rockville, MD: National Institute on Drug Abuse.

Obot, I.S &Anthony, J. C. (2000). School dropout and injecting drug use in a national sample of white non-Hispanic American adults. Journal of Drug Education, 30 (2), 145-155.

Margaret E. Ensminger

Sion Kim

Jennean Everett

Revised by Isidore S. Obot

Sensation Seeking

Sensation seeking is a personality trait most recently defined by its originator, Zuckerman (1994), as "the seeking of varied, novel, complex, and intense sensations and experiences, and the willingness to take physical, social, legal, and financial risks for the sake of such experience." Alcohol and Drug abuse and Gambling represent expressions of the needs involved in this trait, and over thirty years of research have shown that this trait is central to the initial attraction to drugs and the tendency to engage in social or abusive use of them. Among drug users, high sensation seekers are likely to use more kinds of drugs than moderate sensation seekers (varied experience), to use psychedelic drugs (novelty), and stimulants (intensity). However, they also use depressants like Opiate drugs for the sake of the highs of the "rush" and the sensations of the subsequent depressant phase.

Drug users rate higher in sensation seeking than users of alcohol, only showing their willingness to take the extra risks associated with the use of illegal substances. Sensation seeking is involved in many other kinds of interests and activities related to alcohol and drug use including smoking, illicit or unsafe sex, disinhibited partying, reckless driving, and criminal activities.

Sensation seeking has been assessed most often using the Sensation Seeking Scale which contains four subscales: Thrill and Adventure Seeking, Experience Seeking, Disinhibition, and Boredom Susceptibility. The last three of these are most related to drug use. A total score is obtained by summing the four subscales. A newer scale is called Impulsive Sensation Seeking because it combines sensation-seeking items with those of a closely related trait, impulsiveness.

Many studies have shown that sensation seeking is related to current heavy alcohol use and illegal drug use among adolescents and young adults, and other studies (Bates et al., Cloninger et al., Teichman et al.) have demonstrated that sensation seeking at pre- or early adolescence predicts later alcohol and drug use during early adulthood. Lewis Donohew and his colleagues have designed communications for antidrug campaigns based on the sensation seeking traits of those at risk for use and abuse of drugs. The general tenor of these advertisements is that there are healthier ways to seek stimulation than through drugs. The style of the presentations as well as the content is aimed at high sensation seekers.

This writer's experience with treatment of drug abusers in a therapeutic community suggested that the trait is an important consideration in predicting outcome in combination with other traits and environmental considerations. Drug abusers who were also high sensation seekers had a special susceptibility to boredom. What can substitute for the kind of exciting lives they led as part of the drug scene? If they cannot obtain an interesting job, providing varied kinds of stimulation, or if they cannot find exciting friends like those still involved with drugs, they soon turn to drugs themselves. Therapists sometime assume that drugs were used to deal with Anxiety and Depression, or as "self-medication." This only happens in a minority of cases. Early substance abuse is primarily driven by sensation seeking and impulsivity, not by neurotic needs. Anxiety and depression usually emerge as a reaction to drugs or their Withdrawal and to the stresses of drug-life and quickly subside when the user is in effective treatment setting or abstinent after Detoxification. When bored and frustrated in attempts to find interesting work, or working at a monotonous job, the high sensation seeker is most vulnerable to relapse.

(See also: Adolescents and Drug Use ; Conduct Disorder and Drug Use ; Prevention )

BIBLIOGRAPHY

Bates, M. E., La Bourie, E. W., & White, H. R. (1985). A longitudinal study of sensation seeking needs and drug use. Paper presented at the 93rd Annual Convention of the American Psychological Association, Los Angeles, CA, August 23-27.

Cloniner, C. R., Sigvardsson, S., & Bohman, M. (1988). Childhood personality predicts alcohol abuse in young adults. Alcoholism: Clinical and Experimental Research, 12, 494-505.

Donohew, L., Lorch, E. P., & Palmgreen, P. (1998). Applications of a theoretic model of information exposure to health interventions. Human Communications Research, 24, 454-468.

Teichman, M., Barnea, Z., & Rahav, G. (1989). Personality and substance abuse: A longitudinal study. British Journal of Addication, 84, 181-190.

Zuckerman, M. (1979). Sensation seeking: Beyond the optimal level of arousal. Hillsdale, NJ: Erlbaum.

Zuckerman, M. (1983). Sensation seeking: The initial motive for drug abuse. In E. Gotheil et al. (Eds.), Etiological aspects of alcohol and drug abuse (pp. 202-220). Springfield, IL: Charles C. Thomas Publishers.

Zuckerman, M. (1987). Is sensation seeking a predisposing trait for alcoholism? In E. Gottheil, et al. (Eds.), Stress and addiction (pp. 283-301). New York: Bruner/Mazel.

Zuckerman, M. (1994). Behavioral expressions and biosocial bases of sensation seeking. New York: Cambridge University Press.

Marvin Zuckerman

Sexual and Physical Abuse

An increased recognition of the experience of physical and sexual abuse in the lives of many children and Adolescents has led to the increased interest in the impact of such abuse on drug use (Cavaiola & Schiff, 1989; Straus & Gelles, 1990; Dembo et al., 1988). In their 1985 survey of over 6,000 families in the United States, Straus and Gelles (1990) report that 23 per 1,000 children (2.3%) are seriously assaulted every year. Data from a 1991 telephone national survey of women indicate that about 20 per 100 (20%) of the sample reported one or more childhood sexual-abuse experiences (Wilsnack et al., 1994). Few research studies have focused specifically on the question of whether children who are physically and sexually abused are at increased risk of substance abuse. Dembo et al. (1988) suggest three reasons why child abuse has not been included in the conceptual schemes examining the process by which youths become involved in drug use. First, Child Abuse has only recently (in the 1980s) surfaced as an issue receiving research and policy attention. Second, both child-abuse experiences and illicit drug use are often hidden phenomena, so that any covariation in their occurrence is difficult to observe. Third, the focus on social-psychological and socio-cultural factors left little opportunity for child-abuse variations to be considered. Throughout the 1980s and into the 1990s, there has been increasing recognition of the potential importance of abuse to the child's and adolescent's emotional development and the potential connection to substance use and other problem behaviors (Widom, 1991; Zingraff et al., 1993). The central hypothesis guiding research is that physically and sexually abused children and adolescents may use illicit drugs to help cope with the emotional difficulties caused by their negative self-perceptions or other internal difficulties that result from the abuse (Cavaiola & Schiff, 1989; Singer, Petchers, & Hussey, 1989; Dembo et al., 1988).

Much existing research has concentrated on cohorts of adolescents. The rationale for the vulnerability of childhood victims of abuse to drug dependence in adolescence includes first, the ramifications of abuse for lowering self-image and self-esteem, while increasing self-hatred. Based on Kaplan, Martin, and Robbins' (1984) proposition that self-derogation leads to drug use, this model suggests that the abuse of children is related to illicit drug use, both directly and as mediated by self-derogation (Dembo et al., 1988). Second, drugs may provide emotional or psychological escape and self-medication for young abuse victims; they may turn to drugs to chemically induce forgetting or to cope with feelings of Anxiety (Miller, 1990). Third, drug use may provide abused children or adolescents with a peer group, in the form of a drug culture, hence reducing feelings of isolation and loneliness (Singer, Petchers, & Hussey, 1989; Widom, 1991).

Methodological limitations have prevented the existing research from giving a definitive answer. According to Widom (1991), most studies of the association between illicit drug use and childhood victimization have focused on sexually or physically abused children in clinical or institutional settings, making it difficult to generalize to other populations; the studies are often cross-sectional in design, include only retrospective information about childhood-abuse experiences, and do not utilize control groups. Therefore, the validity and reliability of these data have been criticized. Since abuse-related consequences can vary across the life span, cross-sectional studies may miss important ramifications of abuse and it may be impossible to determine the developmental-causal sequence (Briere, 1992; Dembo et al., 1988). Furthermore, most of the studies do not control for other childhood characteristics that may mediate the effects of abuse. Studies focusing on the abuse victims as adults run further methodological risks. When asked about abuse from their childhood, these adults may forget, redefine events in terms of the present, or repress certain thoughts and events.

In one of the earliest reviews of the impact of sexual abuse in childhood, Browne and Finkelhor (1986) reported that adult Women victimized as children were more likely to manifest Depression, self-destructive behavior, anxiety, feelings of isolation, poor self-esteem, and substance abuse than their nonvictimized counterparts. They distinguished initial effects—identified as the manifestations within two years of termination of abuse—from long-term effects.

In a carefully designed study, Widom (1992) followed two groups in arrest records for fifteen to twenty years. One group of 908 individuals with court-substantiated cases of childhood abuse or neglect was matched according to sex, age, race, and socioeconomic status with a comparison group of 667 children not officially recorded as abused or neglected. As indicated by arrest records, the behavior of those who had been abused or neglected was worse than those with no reported abuse—abused or neglected children were more likely to be arrested as juveniles, as adults, and for a violent Crime. With regard to drug use, as adults, the abused and neglected females were more likely to be arrested for drug offenses compared to the nonabused females. In a large sample (N = 3018) of Alabama 8th and 10th graders, Nagy et al. (1994) found that about 10 percent (13% of females and 7% of males) of the students reported being sexually abused. Sexual abuse was defined to include one or more episodes of forced intercourse. Both sexually abused males and sexually abused females reported a higher use of illegal drugs in the past month than those students who did not report sexual abuse. While the associations were strong, the analyses did not attempt to control for confounding variables and were cross-sectional rather than longitudinal, so that causality cannot be inferred.

Wilsnack et al. (1994), using a national sample of adult women, examined the abuse of alcohol and drugs by women who reported retrospectively on whether they had been sexually abused as children. They found strong positive associations between being abused sexually as a child and six different measures of drinking behaviors and two summary drug-use measures. While these analyses are considered preliminary by the authors, because they do not attempt to control for confounding variables, the findings do suggest that early sexual trauma may be an important risk factor for substance abuse later in life.

In a retrospective study, Miller (1990) compared forty-five alcoholic women with forty women chosen randomly from the same community. The relationships between child abuse by the father and the development of alcoholism was examined by controlling on the parents' alcohol problems, family structure during childhood, income source, and age. Higher levels of negative verbal interaction and higher levels of moderate and serious violence were both predictive of those who were found in the alcoholic group.

In their review and synthesis of empirical studies regarding the impact of sexual abuse on children, Kendall-Tackett, Williams, and Finkelhor (1993) found that poor self-esteem was a frequently occurring consequence of sexual abuse. They also conclude that substance abuse, while being a common behavior for sexually abused adolescents, is not an inevitable outcome. In a residential treatment center, Cavaiola and Schiff compared with two control groups the self-esteem of 150 physically or sexually abused, chemically dependent adolescents. The results showed that abused chemically dependent adolescents had lower self-esteem than the two comparison groups; they found negligible difference between those who had been sexually abused and those who had been physically abused.

In two populations of youths studied in a juvenile detention center, Dembo et al. (1988, 1989) compared the lifetime drug use between detainees and a comparable age group in an adjacent county. The studies showed that the detainees' sexual victimization and their physical-abuse experiences related significantly to their lifetime use of illicit drugs. Sexual victimization had a direct effect on the frequency of lifetime drug use, whereas physical abuse had both a direct and an indirect effect on drug use, mediated by the adolescents' feelings of self-derogation. These findings were based on multiple-regression analyses that included family background, other risks for drug use, race, and sex.

CONCLUSION

Despite methodological issues, the body of available evidence suggests that involvement in substance use as an adolescent or adult is linked to an increased likelihood of having experienced physical or sexual abuse as a child. Owing to limitations in the retrospective, cross-sectional, and correlational designs of the research, causal linkages cannot be definitively attributed, and as Briere (1992) notes, while much of the existing research is flawed in its design, it has set the stage for the development of more tightly controlled and methodologically sophisticated studies that will be able to better disentangle the antecedents, correlates, and impacts of sexual and physical abuse.

Further research is needed to examine questions in which our knowledge is meager. First, are there different effects from physical abuse, sexual abuse, or neglect on substance use or dependence? Do other psychosocial factors lead to substance abuse? Second, does the perpetrator of the abuse matter for the impact? Third, does continuity or duration of the abuse matter? Fourth, and perhaps most important, what are the links between suffering maltreatment as a child and later alcohol or drug problems?

(See also: Families and Drug Use ; Family Violence and Substance Abuse )

BIBLIOGRAPHY

Briere, J. (1992). Methodological issues in the study of sexual abuse effects. Journal of Consulting and Clinical Psychology, 60, 196-203.

Browne, A., & Finkelhor, D. (1986). Impact of child sexual abuse: A review of the research. Psychological Bulletin, 99 (1), 66-77.

Cavaiola, A. A., & Schiff, M. (1989). Self-esteem in abused chemically dependent adolescents. Child Abuse and Neglect, 13, 327-334.

Dembo, R., etal. (1989). Physical abuse, sexual victimization, and illicit drug use: Replication of a structural analysis among a new sample of high-risk youths. Violence and Victims, 4 (2), 121-138.

Dembo, R., etal. (1988). The relationship between physical and sexual abuse and tobacco, alcohol, and illicit drug use among youths in a juvenile detention center. The International Journal of the Addictions, 23 (4), 351-378.

Kaplan, H. B., Martin, S. S., & Robbins, C. (1984). Pathways to adolescent drug use: Self-derogation, peer influence, weakening of social controls, and early substance use. Journal of Health and Social Behavior, 25, 270-289.

Kendall-Tackett, K., Williams, L. M., & Finkelhor, D. (1993). Impact of sexual abuse on children: A review and synthesis of recent empirical studies. Psychological Bulletin, 113 (1), 164-180.

Kingery, P. M., Pruitt, B. E., & Hurley, R. S. (1992). Violence and illegal drug use among adolescents: Evidence from the U.S. National Adolescent Student Health Survey. The International Journal of the Addictions, 27 (12), 1445-1463.

Miller, B. A. (1990). The interrelationship between alcohol and drugs and family violence. NIDA Research Monograph, No. 103. Rockville, MD: National Institute on Drug Abuse.

Nagy, S., Adcock, A.G., &Nagy, M. C. (1994). A comparison of risky health behaviors of sexually active, sexually abused, and abstaining adolescents. Pediatrics, 93 (4), 570-575.

Straus, M. A., & Gelles, R.J. (Eds.). (1990). Physical violence in American families. New Brunswick, NJ: Transaction.

Singer, M. I., Petchers, M.K., &Hussey, D. (1989). The relationship between sexual abuse and substance abuse among psychiatrically hospitalized adolescents. Child Abuse and Neglect, 13, 319-325.

Widom, C. S. (1991). "Childhood victimization and adolescent problem behaviors." Paper for the National Institute of Child Health and Human Development conference on "Adolescent Problems and Risk-taking Behaviors." April 13-16, Berkeley Springs, WV.

Widom, C. S. (1992). The cycle of violence. Washington, DC: National Institute of Justice Research in Brief: 1-6, October.

Wilsnack, S. C., etal. (1994). "Childhood sexual abuse and women's substance abuse: National survey findings." Paper for the American Psychological Association conference on "Psychosocial and Behavioral Factors in Women's Health: Creating an Agenda for the 21st Century." May 12-14, Washington, DC.

Zingraff, M.T., etal. (1993). Child maltreatment and youthful problem behavior. Criminology, 31 (2), 173-202.

Margaret E. Ensminger

Colleen J. Yoo

Stress

The term "stress" is frequently defined as a process involving perception, interpretation, response and adaptation to harmful, threatening, or challenging events (Lazarus & Folkman, 1984). This kind of conceptualization allows the separate consideration of (1) the events that cause stress (stressors or stressful life events), (2) the cognitive processes that evaluate stress and the availability of resources to cope with the stressor (appraisal), (3) the biological arousal and adaptation associated with the stressor, and (4) behavioral and cognitive response to the stressful event (actual coping). While different models of stress put more or less emphasis on appraisal mechanisms or biological adaptation mechanisms, the concept of an organism responding to substantial threat or danger is basic to most theories of stress (e.g., Cohen et al., 1986; Mason, 1975; Selye, 1976; Hennessy & Levine, 1979).

Stress produces a negative emotional state associated with perception and appraisal of the stressor, its situational and psychological characteristics, and the assessment of resources available for coping. Stress also activates a biological response with sympathetic arousal, activation of the pituitary-adrenocortical axis, and endogenous opioid-peptide release to alert the body to the stressed state and to support adaptation to the situation. Researchers have found two aspects of stressful events that appear to mediate cognitive appraisal and the biological stress response. These are the controllability and predictability aspects of the event. The extent to which an event is predictable (i.e., the individual is aware of an upcoming stressful event and can prepare for it) and controllable (i.e., the individual perceives the situation as one that he/she can control and adapt to) is significantly associated with the magnitude of the biological stress response and the negative emotional state associated with the event (Frankenhauser, 1980; Hennessey & Levine, 1979). Thus, greater the unpredictability and uncontrollability, greater the emotional distress and the biological response associated with the event.

The aversive quality of stressful situations motivate individuals to reduce the stress by using a variety of coping strategies. Lazarus (1966) identified two primary classes of coping: (1) direct action, which is usually behavioral and involves activity aimed at altering the source of stress or one's relationship to it, and (2) palliation, focused on managing one's emotional responses rather than causes of stress. Palliative coping may be behavioral or cognitive; it may include denial, withdrawal, taking drugs, and/or other forms of making oneself feel better (or less bad). Direct action is a manipulative response aimed at changing a stressor, while palliation is generally accommodative. Similar to the above categories are the two types of coping identified by Lazarus & Folkman (1984). These are 'problem-focussed' coping aimed at doing something to alter the source of the stress, and 'emotion-focussed' coping aimed at managing the emotional distress associated with the stressful event. How people cope with stressful events is key to their success in reducing the associated distress and producing an effective adaptive response to similar stressful situations in the future.

STRESS AND INCREASED VULNERABILITY TO DRUG USE

Most major theoretical models of addiction conceptualize stress as an important factor in the motivation to use addictive substances. For example, the Stress-Coping model of addiction proposes that use of addictive substances serve to both reduce negative affect and increase positive affect, thereby reinforcing drug taking as an effective, albeit mal-adaptive, coping strategy (Wills & Shiffman, 1985). Marlatt's Relapse Prevention model (Marlatt & Gordon, 1985) has proposed that in addition to other bio-psychosocial risk factors such as parental substance use, peer pressure, and positive expectancies regarding the potential benefits of using substances, individuals who have poor ways of coping with stressful events are at increased risk for problematic use of addictive substances. Finally, the Tension Reduction Hypothesis (Conger, 1956; Sher & Levenson 1982) and the Self-Medication Hypothesis (Khantzian, 1985) have been proposed stating that people use drugs to enhance mood and alleviate emotional distress. The latter hypotheses propose that the motivation to enhance mood may be high in the face of both acute and chronic distress states. A drug may be used initially to modulate tension or distress; then with repeated success in doing so, it may become a more ubiquitous response to stress or because of the positive expectancies from drug effects, people may come to use drugs in anticipation of both the relief and mood enhancement.

Prospective studies, which measure stressful events and subjective perception of stress as they occur and use them to predict future drug use, have been conducted to examine whether stress increases the vulnerability to drug use. Higher levels of stress and maladaptive coping along with low parental support predict escalation of drug use in adolescents (Wills et al., 1996). Evidence from animal studies further suggest that stressful experiences in early childhood may increase the vulnerability to drug use. Higley and colleagues (1991) studied rhesus monkeys who were reared by mothers (normal condition) or by peers (stressed condition) for the first six months of their life. Peer-reared monkeys consumed significantly more amounts of alcohol than mother-reared adult monkeys. Furthermore, when stress was increased in the adult monkeys via social separation, mother-reared monkeys increased their levels of alcohol consumption to that of peer reared monkeys. Others have found that rats who show greater reactivity to stress and novelty show an increased vulnerability to self-administration of psycho-stimulants such as amphetamines (Piazza et al., 1989; Piazza & LeMoal, 1996). These findings suggest that individual responses to stressful events and previous experience of stressful events may increase the vulnerability to use addictive substances.

Several studies have shown that acute stress increases self-administration of drugs. Acute behavioral stress in laboratory animals leads to increased drinking and drug use in the post-stress period (Nash & Maickel, 1988; Piazza & LeMoal, 1996; Shaham & Stewart, 1994; Goeders & Guerin, 1994; Miczek & Mutschler, 1996). Human laboratory studies demonstrated increased use of addictive substances after stress as opposed to non-stress situations (see Marlatt & Gordon, 1985 for review). Laboratory induction of stress has also been shown to increase craving for addictive substances in addicts (Sinha et al., 1999a; 1999b). In support of the tension reduction hypothesis, some evidence has accumulated to suggest that alcohol dampens the biological stress response in social drinkers (Sher & Levenson, 1982; Finn & Pihl, 1991; Levenson et al., 1987; Sinha et al., 1998), but this effect appears mediated by a family history of alcoholism and other individual difference variables.

Converging lines of evidence cited above support the key role of stress in mediating problem use of addictive substances. Findings suggest that stressful experiences significantly impact the vulnerability to increase substance use. In addition, in individuals using substances regularly, stressful experiences may lead to an escalation of drug use to the point that such use can lead to drug-related problems for the individual. Despite the above evidence, the specific ways in which stress increases drug intake are not well understood. Animal studies suggest that stress alters brain reward pathways such that drugs are likely to feel more reinforcing than in non-stress conditions (Koob & LeMoal, 1997). Whether these alterations can be detected in humans and modified to reduce the negative impact of stress on drug use remains to be established in future research.

CHRONIC DRUG USE AND VULNERABILITY TO STRESS

The question of whether addicts are more sensitive to the effects of stress on drug intake has received recent attention. It is now well known that the most commonly used addictive substances such as alcohol, nicotine, psychostimulants such as amphetamines and cocaine, opiates and marijuana which stimulate the brain reward pathways, also activate brain stress systems by stimulating release of corticotrophin-releasing factor (CRF) which in turn activates the hypothalamic pituitary adrenal (HPA) axis and release of catecholamines (Robinson & Berridge, 1993). With the chronic use of addictive substances, hallmark symptoms of dependence emerge, namely, tolerance and withdrawal, that are associated with changes in the CRF-HPA, dopaminergic and catecholaminergic systems (Robinson & Berridge, 1993; Koob & LeMoal, 1997). Whether this excessive substance use leads to significant 'wear' and 'tear' on the brain systems that it activates, such that these systems may be unable to function normally in addicts is being examined. Stewart and colleagues have shown that in laboratory animals with a history of drug taking, stress results in reinstatement of drug use when the animals are drug free. However, animals experienced in self-administering food, sucrose pellets or sucrose solution, do not show a stress-related increase in these behaviors. Such data has led to the suggestion that it is a history of drug taking that appears to increase vulnerability to stressful events (Stewart, 2000).

Finally, some human studies support the hypothesis that chronic drug use may alter stress and coping. Evidence suggests that baseline responsivity of the CRF-HPA system is altered during acute and protracted withdrawal in alcoholics and cocaine and opiate addicts (Kreek & Koob, 1998). This co-occurs with behavioral symptoms such as increases in irritability, anxiety, emotional distress, sleep problems, dysphoria and restlessness that are common during acute and protracted phases of withdrawal from alcohol, cocaine, opiates, nicotine and marijuana (Diagnostic and Statistical Manual-IV, 1994; Hughes, 1992). Furthermore, high levels of stress are reported in smokers who are unable to quit, while those who abstain show lower levels of stress (Cohen & Lichtenstein, 1990). However, there is also evidence that stressful life events are not associated with subsequent drug use and relapse in addicts after treatment (Hall et al., 1990; 1991). Future research on the psychobiological effects of chronic drug use as they pertain to the addicts' ability to respond to stress and cope with abstaining from drug use, would be relevant in understanding the nature of this association.

SUMMARY

This section outlines the key aspects of stress and coping and how they relate to addictive behavior. Facing stress is basic to all organisms, but how we cope with stress can differ significantly across individuals. The above section outlines two possible ways in which stress has been associated with addictive behavior. The first aspect targets vulnerability to stress and use of addictive substances as a way of coping with stress. The second aspect of the association has only recently received attention, namely, the effect of chronic drug use on stress and coping. Although the above outline presents key evidence to support the important association between stress and addictive processes, the field continues to develop in order to further our understanding on the psychobiological mechanisms that link stress and coping to addictive behaviors.

(See also: Addiction: Concepts and Definitions ; Co-morbidity and Vulnerability ; Complications ; Endorphins ; Epidemiology of Drug Abuse ; Families and Drug Use ; Family Violence and Substance Abuse ; Poverty and Drug Use )

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Lorenzo Cohen

Andrew Baun

Revised by Rajita Sinha