Provider Characteristics Influencing the Prescription of Antidepressants without a Psychiatric Diagnosis in the United States, 2006-2009

Background: Antidepressant prescriptions and use have recently increased and in 2007, antidepressants were the third most prescribed therapeutic drug class in the United States. Furthermore, antidepressant prescriptions without psychiatric diagnosis by primary care providers have been steadily increasing. Methods: Using a retrospective cross-sectional study design, data was obtained from the National Ambulatory Medical Care Survey (NAMCS) database for adults receiving an antidepressant prescription from 2006-2009. Psychiatric and mental health visits indicating use of antidepressants were determined according to mental health diagnosis (as classified per International Classification of Diseases, Ninth Revision Clinical Modification, ICD-9CM, codes 290-319); or indication of depression listed or charted; or Federal Drug Administration (FDA) approved indication for prescription for this class of medication including depression related symptoms. Prescription of antidepressants without any FDA approved indication for that class of medication was considered non-FDA approved. Analysis of associations and adjustment for confounding variables, patient weight and clustering utilized multivariate logistic regression. Results: From 2006-2009, 39% of antidepressants were prescribed without an FDA-approved indication by physician offices. Utilizing multivariate logistic regression the receipt of an antidepressant for a non-FDA approved indication was significantly associated with the following factors: having seen the same provider previously [(OR 95% CI), 1.72(1.41-2.12)], not seeing a primary care physician [0.72(0.61-0.85)], spending less than 20 minutes with the provider [0.62(0.53-0.71)], and continuation of medication [1.32(1.09-1.61)]. Conclusion: Taken together, these results indicate that antidepressants prescriptions without psychiatric diagnosis is occurring in 39% physician-based office visits. The investigation of factors influencing antidepressant prescriptions provides important insight into the current increasing trends.