Adjunctive Risperidone in the Treatment of Generalized Anxiety Disorder: A Double-Blind, Prospective, Placebo-Controlled, Randomized Trial

Background: Residual symptoms despite treatment are common in generalized anxiety disorder (GAD). The Patient-Rated Troubling Symptoms for Anxiety (PaRTS-A) is a newly created and validated instrument that measures the symptoms most troublesome to each individual patient, and was used to test the hypothesis that adjunctive risperidone improves residual GAD symptoms.

Methods: Primary care and psychiatry clinicians enrolled adults (n = 417) with GAD and a Clinical Global Impressions of Severity rating ≥ 4 despite 8 weeks of anxiolytic treatment. Subjects were randomized to adjunctive risperidone or placebo. The primary endpoint was change from baseline to week 4 endpoint in PaRTS-A.

Results: Improvement from baseline to week 4 endpoint in PaRTS-A total score (mean ± SE) was similar between treatment groups (8.54 [0.63] and 7.61 [0.64] for adjunctive risperidone and placebo, respectively; P = .265). Patients in each treatment group exhibited significant improvements from baseline in nearly all patient- and clinician-rated measures. A post-hoc analysis of PaRTS-A symptoms of moderate to severe severity at baseline suggested greater improvement with risperidone than placebo (P = .04). Headache, weight increase, and increased appetite were the most frequently reported adverse events in both groups.

Conclusions: Residual GAD symptoms assessed by the PaRTS-A improved with either adjunctive risperidone or placebo. Alternative analyses or scoring approaches may improve the ability of the PaRTS-A to provide clinically meaningful information on patient-rated symptoms. Further exploration of the benefits of risperidone in patients with more severe GAD may be indicated.

Psychopharmacology Bulletin. 2007;40(3):41–57.