Prior benzodiazepine use and buspirone response in the treatment of generalized anxiety disorder

Background: An earlier preliminary report suggested that prior treatment wi th benzodiazepines might predict a reduced response to buspirone in patient s diagnosed with generalized anxiety disorder (GAD). To confirm or refute t his hypothesis, the present data analysis was conducted. Method: One large data set (N = 735) of GAD patients (DSM-III) treated with buspirone, a benzodiazepine, and a placebo was analyzed by dividing all pa tients into 3 prior benzodiazepine (BZ) treatment groups: no prior BZ treat ment, recent (< 1 month) BZ treatment, and remote (greater than or equal to 1 month) BZ treatment. Using an intent-to-treat last-observation-carried-f orward (LOCF) data set, acute 4-week treatment response was assessed in ter ms of clinical improvement, attrition, and adverse events as a function of these 3 prior benzodiazepine treatment groups. Results: Patient attrition was significantly higher (p < .05) in the recent BZ treatment group than in the remote and no prior BZ treatment groups wit h lack of efficacy given as the primary reason by patients receiving buspir one but not benzodiazepine or placebo. In the buspirone group, adverse even ts occurred more frequently in the recent BZ treatment group than in the re mote BZ treatment and no prior BZ treatment groups. Finally, clinical impro vement with buspirone was similar to benzodiazepine improvement in the no p rior BZ treatment and remote BZ treatment groups, but less than benzodiazep ine improvement in the recent BZ treatment group, leading to the smallest b uspirone/placebo differences in improvement in the recent BZ treatment grou p. Conclusion: These data suggest that the initiation of buspirone therapy in GAD patients who have only recently terminated benzodiazepine treatment sho uld be undertaken cautiously and combined with appropriate patient educatio n.