Depression: diagnosis and treatment with tricyclic antidepressants.

Recognition of depression as a psychobiologic disorder, its division into categories more descriptive than "endogenous" and "reactive," and use of certain laboratory tests in suspected major (primary) depression have led to increased accuracy of diagnosis. An episode of major depression now can be readily identified by conformance to descriptive criteria, can be confirmed by results of neurophysiologic testing, and can be treated with a tricyclic antidepressant and psychotherapy.