Prevalence of severe depression in private practice depressed outpatients

The prevalence of severe depression, defined by a score of 50 or less on the Global Assessment of Functioning (GAF) scale, and comparisons between severe and non-severe depression, were studied in 203 consecutive unipolar and bipolar depressed outpatients presenting for treatment of depression in private practice. The prevalence of severe degression was 42%. Of the variables investigated (unipolar/bipolar diagnosis, age at baseline/onset, gender, atypical features, psychotic features, comorbidity, chronicity, recurrences, duration of illness, baseline severity), a bipolar I diagnosis and psychotic features were significantly more common in severe depression, while comorbidity and recurrences were significantly more common in non-severe depression. Contrary to the hypothesis that an affective disorder is a progressive illness, the pattern of severe depression did not show more recurrences, more chronicity, or a longer duration of illness than non-severe depression. The findings might be related to the sample studied, as private patients are usually less severely ill than patients in public or university hospitals.