ELSEVJER Differences Between Detected and Und Patients in Primary Care and Depressed Psychiatric Patients Thomas L. Schwenk, M.D., James C. Coyne, Ph.D., and Suzanne Fechner-Bates, Ph.D. Abstract: The aim of this study was to explore differences between primary care and tertiary psychiatry patients meeting DSM-III-R criteria for depressive disorders in terms of a wide range of demographic and clinical variables including psychi- atric comorbidity. A weighted sample of 153 depressed primary care patients was obtained from the waiting rooms of family physicians using a two-stage selection and assessment proce- dureincludingthe Structured ClinicalInterviewfor the DSM- III-R (SCID). A measure of physician detection was also ob- tained. The 123 depressed psychiatric patientswere seeking evaluation and treatment at a university-based depression pro- gram, and DSM-III-R diagnoses were also obtained usingthe SCID. Overall, fewer depressed prima y care patients metcri- teria for major depressive disorder, and more of those who did wereonly mildly depressed. Depressed primary care patients were more likely to be women, older, and had less education, less past treatment, and greaterlifetime comorbidity. Clinical differences were greatest for the depressed patients who had gone undetected by theirphysicians: theywere higherfunction- ing, less distressed, and more mildly depressed. Findings are discussed in terms of the validity and acceptability of practice guidelines for depression in prima y care. 0 1996 Elsevier Science Inc. Introduction Most research on the nature, diagnosis, and treat- ment of depression has been conducted in tertiary psychiatric settings rather than in primary medical care Ill. The Depression Guideline Panel [2,31, es- tablished by the Agency for Health Care Policy Re- Department of Family Practice, The University of Michigan Medical Center, Ann Arbor, Michigan Address reprint requests to: Thomas L. Schwenk, M.D., Uni- versity of Michigan Medical Center, Department of Family Prac- tice, 1018 Fuller Street, Ann Arbor, MI 48109-0708. General Hospital Psychiatry 18, 407-415, 1996 0 1996 Elsevier Science Inc. 655 Avenue of the Americas, New York, NY 10010 search, has concluded that the validity of findings from mental health settings is such that generaliza- tion to primary medical care is warranted. How- ever, there have been long-standing concerns about differences between patients in specialty vs primary medical care settings [41, and more specifically, questions about the comparability of patients in psychiatry vs primary medical care fS--72. Unfortu- nately, there are very few studies making direct comparisons and there are methodological limita- tions to all of them. Previous Studies Earlier British studies concluded that much of the depression in primary care is milder and shorter in duration than what is presented in men&l health settings [8,9]. However, these differences were probably due in part to stricter referral patterns and the inability of patients to self-refer in the British system. Limited research conducted in American settings has produced mixed results. There have been indications in these studies that depressed pri- mary care and psychiatric patients amble each other [lOI and that psychiatric patients are more severely depressed [ill, but sample sizes have been small. Data from the NIMH Epidemiologic Catch- ment Area (ECA) study has been used to argue that studies of psychiatric patients can be used to make generalizations about depressed primary care pa- tients, but only if demographic differences are taken into account 1121. The ECA data suggested that de- pressed persons utilizing the two types of settings are similar in symptom profiles and psychiatric co- 407 ISSN Ol&8343/96/$15.00 PII Sol 63-8343(96)00062-X