The clinical course of undiagnosed depressions

A retrospective study of the clinical course of undiagnosed depression was carried out. During a consecutive 12-month period patients admitted to the psychiatric service of a hospital were interviewed, and the Zung Self-rating Depression Scale (SDS) given. All patients who were regarded as depressed by the investigator were given the SDS on admission and discharge. Patients with depression as a primary or secondary discharge diagnosis were treated for their depressive illness and results of their treatment were reflected by improved post-treatment depression scale ratings. Patients who did not have any discharge diagnosis of depression were not treated, and showed no improvement on their depression scale ratings over time.