Outcomes of Minor and Subsyndromal Depression among Elderly Patients in Primary Care Settings

4 April 2006 | Volume 144 Issue 7 | Pages 496-504

Background: Although depressive conditions in later life are a major public health problem, the outcomes of minor and subsyndromal depression are largely unknown.

Objective: To compare outcomes among patients with minor and subsyndromal depression, major depression, and no depression, and to examine putative outcome predictors.

Design: Cohort study.

Setting: Patients from primary care practices in greater New York City, and Philadelphia and Pittsburgh, Pennsylvania.

Patients: 622 patients who were at least 60 years of age and presented for treatment in primary care practices that provided usual care in a randomized, controlled trial of suicide prevention. Of the 441 (70.9%) patients who completed 1 year of follow-up, 122 had major depression, 205 had minor or subsyndromal depression, and 114 did not have depression at baseline.

Measurements: One year after a baseline evaluation, data were collected by using the following tools: Hamilton Depression Rating Scale, the depressive disorders section of the Structured Clinical Interview for DSM-IV (Diagnostic and Statistical Manual of Mental Disorders, fourth edition), Charlson Comorbidity Index, Multilevel Assessment Instrument for measuring instrumental activities of daily living, Physical Component Summary of the Medical Outcomes Study Short Form-36, and Duke Social Support Index.

Results: Patients with minor or subsyndromal depression had intermediate depressive and functional outcomes. Mean adjusted 1-year Hamilton depression score was 10.9 (95% CI, 9.6 to 12.2) for those with initial major depression, 7.0 (CI, 5.9 to 8.1) for those with minor or subsyndromal depression, and 2.9 (CI, 1.6 to 4.2) for those without depression (P < 0.001 for each paired comparison). Compared with patients who were not depressed, those who had minor or subsyndromal depression had a 5.5-fold risk (CI, 3.1-fold to 10.0-fold) for major depression at 1 year after controlling for demographic characteristics (P < 0.001). Cerebrovascular risk factors were not associated with a diagnosis of depression at 1 year after controlling for overall medical burden. Initial medical burden, self-rated health, and subjective social support were significant independent predictors of depression outcome.

Limitations: Participants received care at practices that had personnel who had been given enhanced education about depression treatment; 29.1% of participants withdrew from the study before completing 1 year of follow-up.

Conclusions: The intermediate outcomes of minor and subsyndromal depression demonstrate the clinical significance of these conditions and suggest that they are part of a spectrum of depressive illness. Greater medical burden, poor subjective health status, and poorer subjective social support confer a higher risk for poor outcome.

*Additional information regarding the authors' roles as study coordinators is available in the Appendix.

Editors' Notes Context The spectrum of depressive illness includes milder forms, about which we know relatively little. Content Older patients selected from 10 primary care practices for depressive symptoms had major depression, minor or subsyndromal depression, or were not depressed. After 1 year, depression symptom severity was closely associated with the initial depression diagnosis. Patients with minor or subsyndromal depression had a much higher incidence of major depression than nondepressed patients, but most were no longer depressed or still had minor or subsyndromal depression. Cautions Approximately 29% of patients withdrew before the end of the study. Implications Minor or subsyndromal depression causes substantial morbidity and is a risk factor for major depression. —The Editors

 

Author and Article Information

From University of Rochester Medical Center, Rochester, New York; Weill Medical College of Cornell University, White Plains, New York; University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania; and University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania.

Grant Support: PROSPECT is a collaborative research study funded by the National Institute of Mental Health. The 3 collaborative sites include the Advanced Centers for Intervention and Services Research of Cornell University (R01 MH59366, P30 MH68638), the University of Pennsylvania (R01 MH59380, P30 MH52129), and the University of Pittsburgh (R01 MH59381, P30 MH52247, P30 MH71944). Additional small grants came from Forest Laboratories and the John D. Hartford Foundation. Dr. Bruce is a recipient of National Institute of Mental Health grant NIMH K02 MH01634, and Dr. Lyness is supported by NIMH R01 MH61429 and K24 MH71509 from the Institute.

Potential Financial Conflicts of Interest: Consultancies: G.S. Alexopoulos (Forest Pharmaceuticals); Honoraria: G.S. Alexopoulos (Forest Pharmaceuticals, Janssen, Cephalon, Pfizer Inc., Bristol-Myers Squibb, Eli Lilly Inc., Glaxo Wellcome); Grants received: G.S. Alexopoulos (Forest Pharmaceuticals, Cephalon); Other (tablets and placebos): C.F. Reynolds III (Forest Pharmaceuticals, GlaxoSmithKline, Pfizer Inc., Eli Lilly Inc.).

Requests for Single Reprints: Jeffrey M. Lyness, MD, Department of Psychiatry, University of Rochester Medical Center, 300 Crittenden Boulevard, Rochester, NY 14642; e-mail, Jeffrey_Lyness{at}urmc.rochester.edu.

Current Author Addresses: Dr. Lyness: Department of Psychiatry, University of Rochester Medical Center, 300 Crittenden Boulevard, Rochester, NY 14642.

Drs. Heo, Alexopoulos, and Bruce: New York Hospital Cornell Medical Center, 21 Bloomingdale Road, White Plains, NY 10605.

Drs. Datto, Ten Have, and Katz: University of Pennsylvania, 3535 Market Street, Philadelphia, PA 19104.

Drs. Drayer and Reynolds: Western Psychiatric Institute and Clinic, 3811 O'Hara Street, Pittsburgh, PA 15213.

Author Contributions: Conception and design: J.M. Lyness, T.R.Ten Have, I.R. Katz, C.F. Reynolds III, G.S. Alexopoulos, M.L. Bruce.

Analysis and interpretation of the data: J.M. Lyness, M. Heo, C.J. Datto, R. Drayer, I.R. Katz, M.L. Bruce.

Drafting of the article: J.M. Lyness, C.J. Datto, C.F. Reynolds III, G.S. Alexopoulos, M.L. Bruce.

Critical revision of the article for important intellectual content: J.M. Lyness, M. Heo, T.R.Ten Have, C.J. Datto, R. Drayer, C.F. Reynolds III, G.S. Alexopoulos, I.R. Katz, M.L. Bruce.

Final approval of the article: J.M. Lyness, M. Heo, T.R.Ten Have, C.J. Datto, C.F. Reynolds III, G.S. Alexopoulos, I.R. Katz, M.L. Bruce.

Provision of study materials or patients: C.F. Reynolds III, G.S. Alexopoulos, I.R. Katz, M.L. Bruce.

Statistical expertise: T.R.Ten Have, M. Heo.

Obtaining of funding: T.R.Ten Have, C.F. Reynolds III, G.S. Alexopoulos, I.R. Katz, M.L. Bruce.

Administrative, technical, or logistic support: I.R. Katz, M.L. Bruce.

Collection and assembly of data: C.J. Datto, G.S. Alexopoulos, I.R. Katz, M.L. Bruce.