EPIDEMIOLOGY OF AFFECTIVE-DISORDERS

Despite the development of structured interviews and operational diagnostic criteria more than 20 years ago, the lifetime prevalence rates of community studies exhibit wide variability within and between countries. Rates of affective disorders vary as follows: major depressive disorder, 1.2-18.0%, dystymia 1.1-20.6%, bipolar disorder 0.2-3.3%. The differences can partially be explained by variations of instruments and interviews. A non-hierarchical diagnostic approach in psychiatric epidemiology enables clinicians to gain understanding of the patterns of comorbidity between affective disorders and other psychiatric syndromes. Major depression, recurrent brief depression, and hypomania differ in their patterns of association with other disorders. Moreover. subjects with affective disorders with comorbidity for other conditions are more severely,affected, suffer from more symptoms with longer duration, have increased rates of suicide attempts, and seek treatment more often. It is critical for treatment studies to assess comorbid conditions in order to provide a comprehensive approach to treatment, which may be a special challenge to physicians.