DOES RISPERIDONE IMPROVE VERBAL WORKING-MEMORY IN TREATMENT-RESISTANTSCHIZOPHRENIA

Objective: Treatment efficacy in schizophrenia is typically defined in terms of symptom reduction. However, new antipsychotic medications co uld potentially have an impact on aspects of disability, such as neuro cognitive deficits. The authors evaluated the effects of risperidone o n vel bal working memory, a memory component of theoretical interest b ecause of its link to prefrontal activity and of practical interest be cause of its link to psychosocial rehabilitation. Method: Verbal worki ng memory of 59 treatment-resistant schizophrenic patients was assesse d as part of a randomized, double-blind comparison of treatment with r isperidone and haloperidol. Verbal working memory was measured under b oth distracting and nondistracting conditions at baseline and after 4 weeks of both fixed- and flexible-dose pharmacotherapy. Results: Rispe ridone treatment had a greater beneficial effect on verbal working mem ory than haloperidol treatment across testing conditions (with and wit hout distraction) and study phases (fixed and flexible nose). The trea tment effect remained significant after the effects of benztropine cot reatment, change in psychotic symptoms, and change in negative symptom s were controlled. Neither benztropine status nor symptom changes were significantly related to memory Performance. Conclusions: Treatment w ith risperidone appears to exert a more favorable effect on verbal wor king memory than treatment with a conventional neuroleptic. The benefi cial effect appears to be due, at least partially, to a direct effect of the drug, possibly through antagonism of the 5-HT2A receptor. Resul ts from this study suggest that pharmacotherapeutic efficacy in schizo phrenia treatment could be broadened to include impact on neurocogniti ve abilities.