Treatment of cognitive dysfunction in chronic schizophrenia by augmentation of atypical antipsychotics with buspirone, a partial 5-HT(1A) receptor agonist.

OBJECTIVES To assess effects of a semi-acute administration of buspirone in comparison to a placebo on cognitive function and negative symptoms in patients with schizophrenia and schizoaffective disorder. METHODS In a 6-week, double-blind, placebo-controlled, independent groups study 18 subjects (14 males, four females) received in random order either placebo or buspirone (15-30 mg/day). A neuropsychological assessment using the Hopkins verbal learning test (HVLT) simple reaction time (SRT), choice reaction time (CRT), n-back spatial working memory task and the stroop colour and word test was performed at baseline and final visit. Symptom rating scales were administered at testing weeks 0, 2, 4 and 6. RESULTS Repeated measures ANOVA was used to examine changes in performance on tests over time. There were no statistically significant differences between placebo and buspirone treatments on either cognitive function measures or symptom ratings. CONCLUSION Semi-acute adjunct treatment with buspirone may be too short to be clinically efficacious in patients with schizophrenia. Intrinsic activation of 5-HT(1A) receptors by atypical antipsychotics may hinder the ability of buspirone to further improve cognitive functions. Buspirone did not affect clinical outcomes for this chronically ill group of patients being treated with atypical antipsychotic drugs.