To put these findings into context, it is necessary to recognize that data from epidemiologic community samples include many mood-disordered persons who are neither seeking nor receiving treatment for their psychiatric disorders. Assuming that these people are “less ill” than are those in treatment with mental health care specialists, outcomes based on community samples are likely to provide a more optimistic view than are outcomes in primary care or psychiatric outpatient samples. Epidemiology Guideline: The point prevalence for major depressive disorder in the Western industrialized nations is 2.3 to 3.2 percent for men and 4.5 to 9.3 percent for women. The lifetime risk for major depressive disorder is 7 to 12 percent for men and 20 to 25 percent for women. Risk factors for major depressive disorder include female gender (especially during the postpartum period), a history of depressive illness in firstdegree relatives, and prior episodes of major depression. (Strength of Evidence = A.) The above gender difference is found in community samples and, thus, is not due to increased female help-seeking behavior. Prevalence rates for major depressive disorder are unrelated to race, education, income, or civil status. Recent epidemiologic data clearly indicate that the age at onset of major depressive disorder has decreased for the more recently born (the "birth cohort" effect) in many westernized cultures. A recent review of available studies strongly suggests that psychosocial events or stresses may play a significant role in precipitating the first or second episodes of major depressive disorder, but they may play little or no role in the onset of subsequent episodes (Post, 1992). That is, for the recurrent forms of major depressive disorder, new episodes are less likely to involve a specific precipitant as the disorder becomes more firmly established. Individuals with major depressive disorder, as well as those with dysthymic disorder and DNOS, are high users of medical services and are as functionally impaired as are patients with severe chronic medical disorders (Katon, von Korff, Lin, et al., 1990; von Korff, Ormel, Katon, et al., 1992; Weissman, Leaf, Tischler, et al., 1988; Weissman and Myers, 1978). The lifetime psychiatric co-morbidity rate for major depressive disorder can be as high as 43 percent (Sargeant, Bruce, Florio, et al., 1990). That is, up to 43 percent of patients with major depressive disorder have histories of one or more nonmood psychiatric disorders. The 1-month point prevalence for concurrent in contrast to lifetime psychiatric comorbidity is 8 percent. Depressive conditions are highly prevalent in primary care settings (Johnson and Weissman, unpublished manuscript). Prevalence rates of depression based on chart notations by primary care physicians vary from 1.5 to 4.5 percent. Structured psychiatric interviews based on standard diagnostic systems (DSM-III-R or ICD-9) provide the best prevalence data because they identify all who have the conditions and differentiate them from those with depressive symptoms from other causes. (However, even many of the studies in which the investigators used structured interviews may not fully exclude patients whose depression was caused by concurrent nonpsychiatric medical disorders, medications, or substances of abuse.) Eleven studies have used structured psychiatric interviews and specific diagnostic criteria to determine the prevalence of major depressive disorder in primary care settings (Table 2). The point prevalence of major depressive disorder in primary care outpatient settings ranged from 4.8 to 8.6 percent; 14.6 percent of adult medical inpatients studied met ICD-9 criteria for major depressive disorder (Feldman, Mayou, Hawton, et al., 1987). Costs of Untreated Major Depressive Disorder Guideline: Patients with major depressive disorder have substantial amounts of physical and psychological disability, as well as occupational difficulties. (Strength of Evidence = A.) Untreated major depressive disorder has a substantial effect on health and functioning. Patients in a major depressive episode report substantially poorer intimate relationships and less satisfying social interactions than do members of the general population who have previously suffered from depression or who currently have other psychiatric disorders (Fredman, Weissman, Leaf, et al., 1988). Physical complaints are also common during a major depressive episode. Twenty-three percent of patients in one study reported some days in which their health kept them in bed all or most of the day in the previous 2 weeks, compared to 5 percent for the general population (Wells, Golding, and Burnam, 1988a). This finding is supported by reports of the health status of community respondents with major depressive disorder, 48 percent of whom described their health as either fair or poor, compared to only 19 percent of the general population (Wells, Golding, and Burnam, 1988a). Other general population data indicate that patients with major depressive disorder reported 11 disability days per 90-day interval versus 2.2 disability days for the general population (Broadhead, Blazer, George, et al., 1990). Data from community respondents indicate that 38 percent of patients with major depressive disorder have some chronic activity restriction, and 30 percent of those with depression reported decreased activity days in the previous 2 weeks (Wells, Golding, and Burnam, 1988a). Clinical samples of patients with major depressive disorder also provide evidence of severe impairment in interpersonal and occupational Table 2. Prevalence of major depressive and other mood disorders = = = Note: SCL = Symptom Checklist. SADS-RDC Schedule for Affective Disorders and Schizophrenia-Research Diagnostic Criteria. GHQ = General Health Questionnaire. PSE Present State Examination. DIS = Diagnostic Interview Schedule. SADS-L Schedule for Affective Disorders and Schizophrenia--Lifetime Version. MDD = major depressive disorder. ECA Epidemiologic Catchment Area. CES-D = Center for Epidemiological Studies Depression Scale. = functioning, including loss of work time (Wells, Stewart, Hays, et al., 1989). Patients with major depressive disorder have more physical illnesses than do other patients seen in primary care settings (Coulehan, Schulberg, Block, et al., 1990). Health care utilization is increased in persons in the community with major depressive disorder compared to other patients in the general medical setting (Regier, Hirschfeld, Goodwin, et al., 1988). Major depressive disorder is associated with increased mortality, which is generally considered to be secondary to suicide and accidents (Wells, 1985). A recent report indicated that patients with major depressive disorder admitted to nursing homes had a 59 percent greater likelihood of death in the first year following admission compared to those without major depressive disorder (Rovner, German, Brant, et al., 1991). Patients with major depressive disorder in the ECA Study aged 55 and over had a mortality rate over the next 15 months that was four times higher than that of nondepressed age-matched controls. Up to 15 percent of patients with major depressive disorder severe enough to require hospitalization eventually die by suicide (Coryell, Noyes, and Clancy, 1982). Subgroups of Major Depressive Disorder Studies of major depressive disorder reveal heterogeneity with regard to the biology, family history, pharmacologic response, genetics, and course of illness. Several schemes have been proposed to subdivide major depressive conditions. The common subgroups and possible clinical relevance of each are shown in Table 3. These subtypes are not allinclusive. For example, a large number of patients who have major depressive disorder without melancholic, psychotic, or atypical features have episodes that are not seasonally related and do not have a postpartum onset. Three subgroups based on cross-sectional symptom features— psychotic, melancholic, and atypical-may have implications for treatment selection. Two based on course features-seasonal pattern and postpartum onset-have prognostic utility; the seasonal type may also suggest the specific therapeutic option of light therapy. However, these subgroups may not be etiologically distinct. Rather, they may represent varying clinical expressions of the same condition over time, in different age groups, or in the context of particular provoking stimuli. Psychotic Features Guideline: Psychotic features refer to the presence of delusions or hallucinations. They occur in 15 percent of patients with major depressive disorders. (Strength of Evidence = A.) In psychotic depressions, psychotic features are never present without concurrent mood symptoms. Psychotic depressions must be distinguished from schizoaffective disorder. In the latter only, there are periods of at = Note: ECT = electroconvulsive therapy. TCA tricyclic antidepressant. MAOIS oxidase inhibitors. SSRIs selective serotonin reuptake inhibitors. = = monoamine least 2 weeks during which delusions or hallucinations are present without mood disturbances. The content of the hallucinations or delusions in psychotic depressions is usually logically consistent with the predominant sad mood (moodcongruent). For example, there may be a delusion that the patient has |