Clinical evaluation and natural course of depression

Without antidepressant therapy, episodes of clinical depression last from 2 months to several years, with an average of around 5 to 6 months. One-third of the patients recover within a year; probably one out of four untreated episodes may last more than 2 years. Depressive episodes occur, on the average, every 2 to 3 years. ECT and antidepressant drug therapy greatly reduce the duration of episodes and significantly decrease the morbidity and mortality of affective disorders. With modern treatment, during a 5-year follow-up, about one quarter of depressed patients had no recurrent episodes, more than half recovered in less than 2 or 3 months, and about one in seven patients developed chronic depression (episodes lasting longer than 2 years). Suicide attempts were made by one fifth of this group of patients, and 6% committed suicide. However, three-fourths of the patients were well three-fourths of the time. Age and culture seem to influence the course of depression. In addition to the classified clinical depressions, there is a considerable prevalence in the general population of depressive symptomatology and dysphoric states, apparently related to genetic factors, age, and stress. Little is known about the course and indications for treatment of these latter conditions, which should be the target for more systematic study and research in the ever widening fields of the phenomenology and therapy of depression.