Continuation of Discussion of Mood Disorders~Mood Disorders~Classification of Mood Disorders-Bipolar Disorders

Mood disorders are largely divided into two major categories in DSM-IV-TR (Diagnostic and Statistical Manual, fourth edition): depressive disorders (often referred to as unipolar disorder) and bipolar disorder. Once a depressive or manic episode occurs, the disorder is classified into both a category and a subcategory.

Depressive Disorders
These include major depressive disorders, dysthymic disorder, and depressive disorders not otherwise specified. All of these disorder classifications include no history of a manic episode. People who experience a major depressive episode are given the diagnosis of major depression. Symptoms should have been present for at least two weeks and should represent a change from the individual's previous functioning. The symptoms of major depression include a depressed mood or loss of interest or pleasure, weight gain or loss, sleep difficulties, fatigue, feelings of worthlessness, inability to concentrate and recurrent thoughts of death. If the episode is the person's first, it is classified as a single episode. For people who have had previous episodes, the disorder is considered a recurrent one. About one-half of those who experience a depressive episode eventually have another episode. In general, the earlier the age of onset, the more likely is a recurrance (Reuss, 1988).

If a disorder is characterized by depressed mood but does not meet the criteria for major depression, dysthymic disorder may be diagnosed. In dysthymic disorder, the depressed mood is chronic and relatively continual. Typical symptoms include pessimism or guilt, loss of interest, poor appetite or overeating, low self-esteem, chronic fatigue, social withdrawal, or concentration difficulties. Unlike major depression, dysthymia may last for years, although the symptoms are often not as severe (D. Klein et al., 1998). Each year, about 10% of individuals with dysthymia go on to have a first major depressive episode. In dysthymia, the depressive symptoms are present most of the day and for more days than not during a two-year period (or, for children and adolescents, a one-year period). One study (Myers et al., 1984) found that the prevalence of dysthymia to be higher among women than men. Overall the lifetime prevalence is about 6% (American Psychiatric Association, 2000), [DSM-IV-TR].


Bipolar Disorders
The essential feature of bipolar disorders is the occurrence of one or more manic or hypomanic episodes; the term bipolar is used because the disorders are usually accompanied by one or more depressive episodes. Symptoms of manic episodes include abnormally and elevated, expansive, or irritable moods lasting at least one week in the case of mania and four days in the case of hypomania. Grandiosity, decreased need for sleep, flight of ideas, distractibility, and impairment in occupational or social functioning are often observed in persons with the disorder.

Bipolar disorders include subcategories that describe the nature of the disorder. Bipolar 1 disorder include single manic episode, most recent episode hypomanic, most recent episode manic, most recent episode mixed, most recent episode depressed,, and most recent episode unspecified. Bipolar II disorder includes recurrent major depressive episodes with hypomania. person in whom manic but not depressive episodes have occurred are extremely rare; in such cases, a depressive episode will presumably appear at some time. Interestingly, mood disorders, especially bipolar conditions, have been associated with artistic talent (Jamison, 1996). For example, Michelangelo, Van Gogh, Tchaikovsky, F. Scott Fitzgerald, Ernest Hemingway, and Walt Whitman experienced such disorders. It is not known why this association occurs, although it should be noted that most people with mood disorders are not especially creative. Perhaps the elevated energy, expansiveness, and uninhibited mood may contribute to productivity and novel ideas.

In contrast to the much higher lifetime prevalence rates for depressive disorders, the lifetime prevalence rates for bipolar 1 and bipolar II hover around 0.8 and 0.5%, respectively (Weissman et al., 1991). Unlike depression, there appear to be no major gender differences in the prevalence of bipolar disorders (Dubovsky & Buzan, 1999). Some people have hypomanic episodes and depressed moods that do not meet the criteria for major depressive episode. If the symptoms are present for at least two years, the individuals are diagnosed with cyclothymic disorder. (For children and adolescents, one year rather than two years is the criterion.) As in the case of dysthymia, cyclothymic disorder is a chronic and relatively continual mood disorder in which the person is never symptom free for more than two months. With lifetime prevalence between 0.4 and 1%, cyclothymia is less common than dysthymia. The risk that a person with cyclothymia will subsequently develop a bipolar disorder is 15-50% (American Psychiatric Association, 2000).


This text is taken from the book 'Understanding Abnormal Behavior',pp. 352-353, written by David Sue, Derald Wing Sue, Stanley Sue, seventh edition, copyright 2003-Houghton Mifflin Company.Used with permission.