Overdiagnosis of depression in the general hospital.

To test the hypothesis that depression is often inaccurately detected in medical settings, we examined the psychiatric consultations performed at two medical-surgical teaching hospitals. All records for the 4396 consultations seen in a 3-year period were retrospectively reviewed. Consultations were categorized by the reason for referral. These reasons were compared with the consulting psychiatrist's diagnosis. Diagnoses were grouped into "Depressed" and "Not Depressed" categories, depending on whether the psychiatric diagnoses implied any form of depressive illness (alone or in combination with other diagnoses). The majority of the referrals for psychiatric consultation (about 25% and 30% at the respective sites) were for presumed depression. Of these referrals for depression, approximately 40% were judged by the consultant to have no depressive diagnosis. Of the referrals for depression judged not to be depressed, the majority had other undiagnosed illnesses, particularly delirium, dementia, and anxiety disorders. The authors conclude that although numerous studies report that depression is unrecognized in medical patients, it may also be inappropriately suspected. This is of most concern when the presumption of depression delays other medical, neurological, or psychiatric evaluation.