Antidepressants are used more commonly than any other form of psychotropic medication. Treatment with antidepressants is increasing while the use of psychotherapy appears to be declining (1,2). Antidepressant use increased by 115 percent between 1993 and 1998 alone (3). However, not all of this increase can be attributed to increased treatment of depression. This study examined the proportion of members of a private health insurance plan who received an antidepressant and the extent to which this use was accompanied by other mental health care.

Data were drawn from Medstat's 2002 MarketScan Database, a convenience sample of more than 5.5 million privately insured employees and their dependents aged 0 to 64 years from the largest U.S. firms, covering a wide range of health plans and employers. Mental health service use was identified by scanning all 2002 claims and encounters for selected diagnoses, provider types, and procedure codes. Antidepressant use was identified from pharmaceutical claims. Mental health service use was defined as a claim with one of the following: a primary or secondary diagnosis of a mental health or substance use disorder, including tobacco addiction; a service provided by a mental health specialist; or a service coded as individual or group counseling or as mental health or substance abuse treatment.

Antidepressant use with or without other mental health service use was common in 2002. Eleven percent of the enrollees received at least one antidepressant during the year (F1).

A majority of patients who used antidepressants did not receive any other mental health care or a diagnosis of a mental health or substance use disorder. Furthermore, one-fifth of antidepressant users (19.4 percent) did not have any claims for mental health care and had one of several medical conditions known to be associated with off-label use of antidepressants. These findings suggest that, to some degree, analyses that assume that all antidepressant users receive treatment for a mental health condition may overstate the number of people who are reached by the mental health system. Research should investigate the basis on which providers are choosing to prescribe an antidepressant when no other apparent mental health care is delivered.

The authors thank Judith Teich, M.S.W., and Jeff Buck, Ph.D. The project was funded by contract 03-M000-1880-1D from the Center for Mental Health Services.

Dr. Larson and Ms. Fleming are affiliated with the Institute for Health Services Research and Policy at New England Research Institutes, 9 Galen Street, Watertown, Massachusetts 02474 (e-mail, mjlarson@neriscience.com). Ms. Miller is with Medstat in Santa Barbara, California. Harold Alan Pincus, M.D., Terri L. Tanielian, M.A., and Amy M. Kilbourne, Ph.D., M.P.H., are editors of this column.