Epidemiology ECA Study data indicate a lifetime rate for dysthymic disorder (with and without major depressive disorder) of 4.1 percent for women and 2.2 percent for men. Women aged 25 to 64 had rates of almost 6 percent. Men 65 and over had the lowest rate (1.0 percent). The 1-month prevalence for dysthymic disorder without major depressive disorder was 0.8 percent. The 1-month prevalence for dysthymic disorder with major depressive disorder was 1.3 percent. ECA Study data indicate that 15 percent of those with dysthymic disorder also have a concurrent nonmood psychiatric disorder, usually alcohol or drug abuse. In adults, dysthymic disorder is more common in women than in men. In children, dysthymic disorder, like major depressive disorder, is equally frequent in both sexes. Dysthymic disorder is more common among first-degree biologic relatives of persons with major depressive disorder or with bipolar I and II disorders than among the general population. The point prevalence of dysthymic disorder in primary care outpatients is 2.1 to 3.7 percent. Costs of Untreated Dysthymic Disorder The functional and financial costs of untreated dysthymic disorder are substantial. In the ECA Study, 29 percent of general medical patients with dysthymic disorder had some chronic restriction of their activity (Wells, Golding, and Burnam, 1988b). Similarly, 27 percent of patients with dysthymic disorder in that community survey showed decreased activities in the previous week. Sixteen percent reported bed days within the previous 2 weeks, compared to only 5 percent of the general population. Furthermore, 39 percent of those with dysthymic disorder said that they had poor or fair health, compared to 19 percent of the general population. Patients with dysthymic disorder reported an average of 3 disability days per 90-day interval, compared to 2 days for the general population. Depression Not Otherwise Specified Clinical Features and Course Guideline: Depression not otherwise specified identifies mood conditions with depressive symptoms that do not meet either severity or duration criteria for dysthymic, major depressive, or bipolar disorders. It is a heterogeneous category. (Strength of Evidence = B.) Examples of DNOS include minor depression (Merikangas, Ernst, Maier, et al., in press), recurrent brief depressive disorder (Merikangas, Hoyer, and Angst, in press), and mixed anxiety/depression (Zinbarg, Barlow, Liebowitz, et al., in press). Whether these three groupings are true disorders is under investigation. Currently, they are not formally recognized diagnoses. They are described here because less than major forms of depression are common in primary care settings. The treatment implications of these groupings are unclear. Minor depressive disorder is symptomatically similar to major depressive disorder, but with fewer symptoms and less disability; symptoms come and go, but are present for at least 2 weeks at a time. Minor depressive disorder does not have the chronic/pervasive, multiyear pattern of dysthymic disorder. Recurrent brief depressive disorder features brief (3 to 7 days) episodes that return 6 to 10 times per year and meet the symptomatic threshold and clinical features of a major depressive episode, but not the 2-week duration criterion (Angst, Merikangas, Scheidegger, et al., 1990). It occurs somewhat more often in women than in men, and the age of onset is late adolescence to the mid-20s. The likelihood of a positive history in firstdegree relatives of patients with recurrent brief depressive disorder is 12 to 20 percent for major depressive disorder and 1 to 3 percent for bipolar disorder. Studies (Zinbarg, Barlow, Liebowitz, et al., in press) have begun to suggest the existence of a disorder involving symptoms of both anxiety and depression that was particularly prevalent among primary care patients, but they did not use DSM nomenclature. Barrett, Barrett, Oxman, et al. (1988) found that 4.1 percent of a sample of 1,055 primary care patients had mixed anxiety/depression, defined as concurrent anxious and depressive symptoms, neither of which was of sufficient frequency or duration to meet criteria for a formal anxiety or mood disorder. Epidemiology An analysis of the ECA Study data showed that 11.0 percent of subjects met the criteria for DNOS. The point prevalence of DNOS in primary care outpatients is 8.4 to 9.7 percent (see Depression Guideline Panel, forthcoming). A reanalysis of the ECA Study 1-year followup data on subjects who had a mood disturbance and two associated symptoms of major depression (an attempt to operationalize DNOS) was commissioned by the panel. The data indicated that for those with DNOS interviewed at 1-year followup, 38 percent were not ill, 52 percent still had DNOS, 3 percent had developed dysthymic disorder, and 9 percent had developed major depressive disorder (Johnson and Weissman, unpublished manuscript). For some patients, substantial morbidity is thus associated with DNOS over 1 year. Fifty percent of patients with DNOS in the ECA sample had one or more of the following co-morbid nonmood psychiatric conditions: alcohol or substance abuse/dependence, panic disorder, obsessive-compulsive disorder, or somatization disorder. Phobic and generalized anxiety disorders were not included. The point prevalence for the 167 subjects with co-morbid DNOS was 40 percent for alcohol dependence, 15 percent for drug dependence, 37 percent for panic or obsessive-compulsive disorder, and 1 percent for somatization disorder. Costs of Untreated DNOS Preliminary evidence indicates that DNOS significantly affects patients' functioning, health, and disability. Patients with DNOS have decreased physical, social, and role functioning (Wells, Stewart, Hays, et al., 1989) and increased disability days. Their current health has been found to be worse than that of those with no chronic condition or those with only chronic medical conditions. Patients with DNOS reported 4 to 6 disability days per 90-day period, compared to the community population rate of 2 days per 90-day period (Broadhead, Blazer, George, et al., 1990). Bipolar Disorders Clinical Features and Course Guideline: Bipolar disorders classically feature episodes of major depression interspersed with episodes of mania and/or hypomania. (Strength of Evidence A.) = The major depressive episodes of bipolar disorder meet the criteria outlined in Table 1. Manic episodes are distinct periods of persistently elevated, abnormally expansive, or irritable mood associated with at least three of the symptoms noted in Table 5. About 3 percent of all bipolar disorder patients experience only manic episodes (so-called unipolar mania). Table 5. DSM-III-R criteria for a manic episode A. A discrete period of abnormal, persistently elevated, expansive, or irritable mood. B. At least three of the following in the same period: (1) Inflated self-esteem/grandiosity. (2) Marked decrease in need for sleep. (3) Much more talkative (pressured speech) than usual. (4) Flight of ideas (rapidly racing thoughts). (5) Marked distractibility. (6) Increased goal-directed activity/psychomotor agitation. (7) Excessive involvement in pleasurable activities without regard for negative consequences (e.g., unrestrained buying sprees, sexual indiscretions, foolish business ventures). C. Symptoms severe enough to impair function markedly or require hospitalization to prevent harm to self or others. D. Not caused by schizophrenia, schizoaffective disorder, or substance abuse. Source: American Psychiatric Association, 1987. Delusions or hallucinations are sometimes present in manic episodes. Their content is usually consistent with the predominant mood (moodcongruent). For example, a patient may hear "God's voice" explaining that the patient has a special mission or special powers. Delusions may be based on the idea that the person is being persecuted because of some special relationship or attribute. Less commonly, hallucinations or delusions have no apparent content relationship to the expansive/irritable mood (mood-incongruent). Disorders with mood-incongruent psychotic features in the manic episode appear to have a poorer prognosis. Although they are similar to manic episodes, hypomanic episodes are milder. They are usually brief periods (4 days to several weeks) in which patients are often mildly dysfunctional. Sometimes, they actually feel very well and are creative, but others see them as different from their normal selves. By definition, psychotic symptoms are never present in hypomanic episodes. Patients often do not recall hypomanic periods as times of illness, though others recognize the disturbance. Persons with bipolar I disorder may have hypomanic episodes as well as manic episodes. In the course of classic bipolar disorder (so-called bipolar I disorder) manic, depressive, and/or mixed manic episodes may occur. (Mixed manic episodes refer to the simultaneous presence of both depressive and manic symptoms in the same episode within the same 24- to 48-hour period.) In bipolar I disorder, manic and depressive episodes are equally frequent. Mixed manic episodes occur in one-third of patients with bipolar I disorder, but these episodes represent only 6 percent of all episodes. The mean age at onset of bipolar disorder is in the early 20s, and the decade for highest risk of onset is 20 to 29 years of age. The sexes do not differ in age at onset. Men are more likely to have initial manic episodes, while women are more likely to experience initial depressive episodes. The mean duration of untreated manic episodes is 6 months; the mean duration of untreated major depressive episodes is approximately 8 to 10 months. The depressive episodes immediately precede and/or follow manic episodes in more than half of cases. The total number of episodes of illness experienced by a patient with bipolar disorder during a lifetime is variable. On the average, the episode risk is 0.3 to 0.4 episodes each year. The time between episodes decreases with subsequent episodes. For individuals, the temporal pattern of episodes tends to repeat itself. Therefore, the future course of illness is best predicted by the individual's prior course. There is usually a full recovery between episodes, although roughly 25 percent have less than full recovery. The morbidity and mortality associated with bipolar I disorder are high. Suicides, "accidental deaths," and intercurrent illnesses contribute to an excessive mortality rate. Ten to 15 percent of untreated patients commit suicide, which is 15 to 20 times the suicide rate in the general population (1 percent over a lifetime of 70 years). Women with bipolar disorder are much more likely than are men to attempt suicide; men are more likely to complete suicide. A large study found that prior to the availability of effective treatment, 23 percent of 4,341 patients with a manic episode admitted between 1912 and 1932 died in the hospital, 60 percent from "exhaustion" (Derby, 1933). Patients with bipolar disorder experience considerable impairment in social and occupational functioning. While manic, they often need to be protected from the consequences of their poor judgment and overactivity, which often results in involuntary hospitalization. Over time, even with periods of remission, the chronicity and unpredictability of the disorder lead to secondary problems, such as joblessness, legal difficulties, divorce, and death by suicide, as well as medical morbidity. Epidemiology Bipolar I disorder affects men and women equally. It has a lifetime prevalence of 0.4 to 1.2 percent. The 1-month prevalence for bipolar disorder is 0.1 to 0.6 percent. Bipolar I disorder occurs at much higher rates in first-degree biologic relatives of persons with bipolar I disorder than in the general population. First-degree relatives of those with bipolar I disorder have a 12 percent chance of having the same disorder over their lifetimes. Another 12 percent have recurrent major depressive disorder, and roughly an additional 12 percent have dysthymic or other mood disorders (Goodwin and Jamison, 1990; Rush, Cain, Raese, et al., 1991). Subtypes of Bipolar Disorder Guideline: Psychoactive substances, such as cocaine and amphetamines; head trauma; certain neurologic diseases; endocrinopathies; and some other disorders can produce secondary manic and hypomanic episodes similar to those seen in primary bipolar disorder. In addition, in some patients with a family history of bipolar disorder, antidepressant medications can precipitate a manic or hypomanic episode. (Strength of Evidence = A.) Case reports suggest that secondary bipolar disorders may be more effectively treated with anticonvulsants than with lithium. (For a review, see Goodwin and Jamison, 1990.) A seasonal pattern has been found in a subset of patients who have bipolar II disorder (and in some, but fewer, cases of bipolar I disorder). The requisite feature is the occurrence of major depressive episodes in a seasonal pattern (typically, fall onset, spring offset). Perhaps 10 percent of patients with bipolar II disorder experience such seasonal episodes. It is unclear whether lithium is differentially effective in these patients and, indeed, whether the disorder becomes nonseasonal over time. Some patients with bipolar I or II disorder exhibit a “rapid cycling" pattern, experiencing four or more mood episodes each year. Mood episodes include manic (or mixed manic-depressive), hypomanic, and major depressive episodes. The mood episodes may follow one another |