Adjunctive Risperidone in Generalized Anxiety Disorder: A Double-Blind, Placebo-Controlled Study

Olga Brawman-Mintzer, M.D.; Rebecca G. Knapp, Ph.D.; and Paul J. Nietert, Ph.D.

Objective: Although significant advances have been made in recent years in the treatment of generalized anxiety disorder (GAD), many patients remain symptomatic despite ongoing treatment, underscoring the need for adjunctive new treatments to help improve response.

Method: Forty patients with a primary diagnosis of DSM-IV GAD, who continued to experience GAD symptoms despite current anxiolytic treatment of at least 4 weeks' duration, as evidenced by Hamilton Rating Scale for Anxiety (HAM-A) total score >= 18 and Clinical Global Impressions-Severity of Illness scale score of moderate or greater, completed a 1-week screening phase and were then randomly assigned to 5 weeks of double-blind adjunctive treatment with placebo or risperidone at flexible doses of 0.5 to 1.5 mg/day. Patients continued to take their anxiolytics throughout the study. The study was conducted from June 2001 through March 2003.

Results: Adjunctive risperidone was associated with statistically significant improvements in core anxiety symptoms, as demonstrated by greater reductions in HAM-A total scores (p = .034) and HAM-A psychic anxiety factor scores (p = .047) compared with placebo. Although change scores on other outcome variables, including response rates, were higher in the risperidone group, differences did not achieve statistical significance.

Conclusion: Study findings suggest that risperidone at low doses may represent a useful tool in the management of symptomatic GAD patients.

(J Clin Psychiatry 2005;66:1321-1325)

Received Feb. 2, 2005; accepted June 16, 2005. From the Departments of Psychiatry (Dr. Brawman-Mintzer) and Biometry and Epidemiology (Drs. Knapp and Nietert), Medical University of South Carolina, and the Ralph H. Johnson VA Medical Center (Dr. Brawman-Mintzer), Charleston, S.C.

This study was conducted with the support of an unrestricted investigator-initiated grant from Janssen Pharmaceutica, Inc., Titusville, N.J.

Presented in part at the European College of Neuropsychopharmacology (ECNP) 16th Annual Meeting; September 20-24, 2003; Prague, Czech Republic.

Dr. Brawman-Mintzer has served as a consultant for Pfizer, Janssen, AstraZeneca, UCB Pharma, and Cephalon; has received grant/research support from Pfizer, Forest, Eli Lilly, Janssen, and AstraZeneca; has received honoraria from AstraZeneca, Forest, Pfizer, Janssen, and Eli Lilly; and has served on the speakers or advisory boards of Pfizer, Forest, AstraZeneca, Janssen, and Eli Lilly. Drs. Knapp and Nietert report no other financial affiliation relative to the subject of this article.

Corresponding author and reprints: Olga Brawman-Mintzer, M.D., 5900 Core Road, Suite 203, Charleston, SC 29406 (e-mail: mintzero@musc.edu).