DIAGNOSING DEPRESSION IN THE MEDICALLY ILL - VALIDITY OF A LAY-ADMINISTERED STRUCTURED DIAGNOSTIC INTERVIEW

Understanding the validity of structured psychiatric diagnostic interv iews in medically ill patients will advance the ability to conduct res earch into the treatment and management of these disorders in general medical settings. We compared the University of Michigan version of th e CIDI (Composite International Diagnostic Interview) for major depres sion to a clinical gold standard, derived through Spitzer's Longitudin al, Expert, All Data (LEAD) criteria based on the SCID-III-R. A conven ience sample of medical inpatients was administered the SCID-III-R and the CIDI for major depression in random order. A physician panel revi ewed the SCID interview and other pertinent data and determined whethe r patients had a lifetime or current (past month) diagnosis of major d epression. The CIDI was scored with and without hierarchical exclusion s for mania, hypomania, substance use, or medical illness. When the UM -CIDI was scored for a lifetime diagnosis of major depression without hierarchical exclusions, agreement above chance (kappa) was very good (kappa=0.67) between the CIDI and the physician panel and good (kappa= 0.46) when the UM-CIDI was scored with exclusions. Agreement above cha nce for diagnosis of a recent disorder was better for UM-CIDI scoring with exclusions (kappa= 0.51) compared to scoring without exclusions ( kappa = 0.43). Predictive value-positive was excellent in both scoring versions for a lifetime diagnosis (82%) and good to very good for cur rent depression (46% and 62%). In all cases predictive value-negative was very good to excellent (77-93%). Discordant cases were almost unif ormly due to difficulties in attribution of symptoms to medical illnes ses. We conclude that the CIDI can perform acceptably as a research in strument to diagnose major depression in medically ill patients, poten tially supplemented by clinician review of cases identified by the CID I with current disorder. (C) 1998 Elsevier Science Ltd. All rights res erved.