An open-label trial of risperidone augmentation for refractory anxiety disorders.

BACKGROUND: There is a paucity of data to support "next-step" treatments for the many patients with anxiety disorders who remain symptomatic after initial pharmacotherapy.

METHOD: Thirty patients with a primary diagnosis of an anxiety disorder-panic disorder (PD), social anxiety disorder (SAD), or generalized anxiety disorder (GAD)-refractory to initial pharmacotherapy with an adequate (or maximally tolerated) antidepressant and/or benzodiazepine trial of at least 8 weeks' duration prior to study initiation received open-label augmentation with flexibly dosed risperidone for 8 weeks. Participants were diagnosed using the Structured Clinical Interview for DSM-IV.

RESULTS: Risperidone augmentation at a mean +/- SD dose of 1.12 +/- 0.68 mg/day (range, 0.25-3.00 mg/day) resulted in a significant reduction in anxiety symptoms across disorders as measured by the Clinical Global Impressions-Severity of Illness scale and Hamilton Rating Scale for Anxiety (HAM-A) scores and for each disorder-specific primary outcome measure-the Panic Disorder Severity Scale, the Liebowitz Social Anxiety Scale, and HAM-A-in the intent-to-treat sample. Seventy percent (21/30) of participants completed the 8-week trial, with premature discontinuation due primarily to sedation and weight gain.

CONCLUSIONS: Although conclusions are limited by the open-label, relatively brief nature of this trial, our data suggest that augmentation with low-dose risperidone may be a useful option for patients with PD, SAD, or GAD refractory to adequate initial intervention with antidepressants and/or benzodiazepines. Longer-term, controlled safety and efficacy data are needed to understand the place of risperidone augmentation in the algorithm of treatment options for refractory anxiety disorders.