Psychiatric diagnosis in clinical practice: Is comorbidity being missed?

The recognition of comorbidity has important clinical significance. Comorbi dity predicts a poorer outcome for patients with depressive and anxiety dis orders, and the presence of multiple psychiatric disorders is associated wi th greater psychosocial impairment. In routine clinical settings, an unstru ctured interview is typically used to assess patients. However, unstructure d interviews may result in missed diagnoses, with potential negative clinic al consequences. The goal of the present study was to examine whether diagn ostic comorbidity is less frequently identified during a routine clinical e valuation versus a semistructured diagnostic interview. Axis I diagnoses de rived from structured and unstructured clinical interviews were compared in two groups of psychiatric outpatients in the same practice setting. Five h undred individuals presenting for an intake appointment to a general adult psychiatric practice underwent a routine unstructured clinical interview. S ubsequent to completion of the first study, the method of conducting diagno stic evaluations was changed and 500 individuals were interviewed with the Structural Clinical Interview for DSM-IV Axis I Disorders (SCID). The two g roups had similar demographic characteristics and scored similarly on sympt om questionnaires. Individuals interviewed with the SCID were assigned sign ificantly more axis I diagnoses than individuals assessed with an unstructu red interview. More than one third of the patients interviewed with the SCI D were diagnosed with three or more disorders, in contrast to fewer than 10 % of the patients assessed with an unstructured interview. Fifteen disorder s were more frequently diagnosed in the SCID sample, and these differences occurred across mood, anxiety, eating, somatoform, and impulse-control diso rder categories. The results suggest that in routine clinical practice, cli nicians underrecognize diagnostic comorbidity. Anxiety, somatoform, and not otherwise specified (NOS) disorders were the most frequently underdetected disorders. The implications of underdiagnosis for the treatment outcome ar e discussed. Copyright (C) 1999 by W.B. Saunders Company.