Depression and Depressive Disorders

Definition

Description

Demographics

Causes and Symptoms

Resources

Definition

Depression or depressive disorders (unipolar depression) are mental illnesses characterized by a profound and persistent feeling of sadness or despair and/or a loss of interest in things that were once pleasurable. Disturbance in sleep, appetite, and mental processes are a common accompaniment.

Description

Everyone experiences feelings of unhappiness and sadness occasionally. But when these depressed feelings start to dominate everyday life and cause physical and mental deterioration, they become what are known as depressive disorders. Each year in the United States, depressive disorders affect an estimated 18.8 million people, or about 9.5% of the adult population, at an approximate annual direct and indirect cost of more than $51 billion. One in four women is likely to experience an episode of severe depression in her lifetime, with a 10-20% lifetime prevalence, compared to 5-10% for men. The average age a first depressive episode occurs is in the mid-20s, although the disorder strikes all age groups indiscriminately,

from children to the elderly. In fact, the rate of increase in depression among children in 23%.

There are two main categories of depressive disorders: major depressive disorder and dysthymic disorder. Major depressive disorder is a moderate to severe episode of depression lasting two or more weeks. Individuals experiencing this major depressive episode may have trouble sleeping, lose interest in activities they once took pleasure in, experience a change in weight, have difficulty concentrating, feel worthless and hopeless, or have a preoccupation with death or suicide. In children, the major depression may appear as irritability.

While major depressive episodes may be acute (intense but short-lived), dysthymic disorder is an ongoing, chronic depression that lasts two or more years (one or more years in children) and has an average duration of 16 years. The mild to moderate depression of dysthymic disorder may rise and fall in intensity, and those afflicted with the disorder may experience some periods of normal, non-depressed mood of up to two months in length. Its onset is gradual, and dysthymic patients may not be able to pinpoint exactly when they started feeling depressed. Individuals with dysthymic disorder may experience a change in sleeping and eating patterns, low self-esteem, fatigue , trouble concentrating, and feelings of hopelessness.

Depression can also occur in bipolar disorder , a mood disorder that causes radical emotional changes and mood swings, from manic highs to depressive lows. The majority of bipolar individuals experience alternating episodes of mania and depression.

Demographics

Major depressive disorder occurs twice as frequently in adolescent and adult females as in the corresponding male populations. Both genders of preadolescent children are affected equally.

Causes and Symptoms

The causes behind depression are complex and not yet fully understood. While an imbalance of certain neurotransmitters—the chemicals in the brain that transmit messages between nerve cells—are thought to be key to depression, external factors such as upbringing (more so in dysthymia than major depression) may be as important. For example, it is speculated that, if an individual is abused and neglected throughout childhood and adolescence, a pattern of low self-esteem and negative thinking may emerge. From that, a lifelong pattern of depression may follow.

Depression is also associated with an imbalance of cortisol, the main hormone secreted by the adrenal glands. Other physiological factors sometimes associated with depression include viral infections, low thyroid hormone levels, and biological rhythms, including women’s menstrual cycles—depression is a prominent symptom of premenstrual syndrome (PMS).

Heredity seems to play a role in the development of depressive disorders. Individuals with major depression in their immediate family are up to three times more likely to have the disorder themselves. It would seem that biological and genetic factors may make certain individuals predisposed or prone to depressive disorders, but environmental circumstances may often trigger the disorder.

External stressors and significant life changes, such as chronic medical problems, death of a loved one, divorce or estrangement, miscarriage, or loss of a job, can also result in a form of depression known as adjustment disorder. Although periods of adjustment disorder usually resolve themselves, occasionally they may evolve into a major depressive disorder.

In addition, chemical imbalance in the brain, certain medical conditions, diet, and alcohol or drug use may lead to depression.

The primary symptoms of major depressive disorder are depressed mood or anhedonia (the inability to enjoy experiences or activities normally considered to be pleasant) over a period of at least two weeks. Other symptoms that may be symptomatic of major depression include:

• change in appetite with marked weight gain or loss
• decreased pleasure or interest in daily activities
• difficulty concentrating
• disturbed sleep patterns (e.g., insomnia or excessive sleep)
• fatigue or loss of energy
• feelings of abandonment
• feelings of guilt
• feelings of overwhelming sadness or fear
• intense feelings of helplessness, hopelessness, worthlessness, anxiety
• recurrent thoughts of death

KEY TERMS

Psychotropic drug —A drug that acts on or influences the activity of the mind.

Treatments

Depression is typically treated with a combination of psychotropic drugs and psychotherapy. Antidepressant medications include monoamine oxidase inhibitors (MAOIs), tricyclic antidepressants, selective serotonin reuptake inhibitors (SSRIs) , norepinephrine reuptake inhibitors (NRIs), norepinephrine-dopamine reuptake inhibitors, serotonin-norepinephrine reuptake inhibitors (SNRIs), and noradrenergic and specific serotonergic antidepressants (NASSAs). Severe cases of depression that are not responsive to these treatments have historically been treated with electroconvulsive therapy (ECT). ECT is a controversial treatment in which controlled, low-dose electrical currents are used to cause a seizure. Although rarely used today, ECT is still sometimes used in the treatment of severe depression. The benefits of ECT in the treatment of depression are temporary. Currently, research is underway investigating the effectiveness of transcranial magnetic stimulation (TMS). TMS is a non-invasive experimental procedure that gently stimulates the brain using short bursts of electromagnetic energy received through focused powerful magnets placed on the patient’s scalp.

Resources

BOOKS

American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders. 4th edition, text revised. Washington, DC: American Psychiatric Association, 2000.

DePaulo, J. Raymond, Jr., and Leslie Alan Horvitz. Understanding Depression: What We Know and What You Can Do About It. New York: John Wiley and Sons, 2002.

Freeman, Arthur; James Pretzer; Barbara Fleming; and Karen M. Simon, Clinical Applications of Cogninitive Therapy, 2nd ed. New York: Kluwer Academic/Plenum Publishers, 2004.

Kasper, Siegfried; Johan A. den Boer; and J. M. Sitsen, Ad, Eds. Handbook of Depression and Anxiety, 2nd ed. New York: Marcel Dekker, 2003.

VandenBos, Gary R., Ed. APA Dictionary of Psychology. Washington, DC: American Psychological Association, 2007.

PERIODICALS

Jarema, Marek, III. “Atypical Antipsychotics in the Treatment of Mood Disorders.” Current Opinion in Psychiatry 20(1) (Jan 2007): 23–29.

Nemeroff, Charles B. “The Burden of Severe Depression: A Review of Diagnostic Challenges and Treatment Alternatives.” Journal of Psychiatric Research 41(3-4) (Apr-Jun 2007): 89-206.

Rihmer, Zolt´n. “Suicide Risk in Mood Disorders.” Current Opinion in Psychiatry 20(1) (Jan 2007): 17–22.

Paula Anne Ford-Martin, M.A.
Ruth A. Wienclaw, Ph.D.