Open, randomized trial of the effect of aripiprazole versus risperidone on social cognition in schizophrenia.

Impairments in social functioning are a hallmark characteristic of schizophrenia. Deficits in social functioning are present throughout the course of the disorder. Indeed, they are even present before the
onset of psychosis (Davidson et al. 1999) and frequently persist despite antipsychotic treatment (Addington & Addington 2000).



The study of social cognition in schizophrenia examines the
processes underlying social dysfunction (Corrigan & Penn, 2001;
Pinkham et al. 2003). Social cognition has been defined as ?the
mental operations underlying social interactions, which include the
human ability to perceive the intentions and dispositions of others?.
A crucial finding is that performance on social cognition tasks predicts social functioning (Penn et al. 2000; Pinkham et al. 2003).



Brain circuits underlying social cognition concern the ventral striatum, the amygdala, the medial prefrontal and orbitofrontal cortex, anterior cingulate, and insula (Phan et al. 2002; Pinkham et
al. 2003). The importance of dopamine pathways in neural processing in these circuits is well established (Grace 2000).



Until now, antipsychotics have not been able to reverse the social deficits associated with schizophrenia, which might be due to their general antagonist activity at dopamine D2 receptors. We
hypothesize that, because of its unique action as a partial dopamine agonist in brain circuits underlying social cognition,
treatment with aripiprazole will lead to a significant improvement in social cognitive processing compared to risperidone. Computerised behavioral tasks are used to measure social cognition and
questionnaires and inventories are used to map social functioning in patients with schizophrenia.

We hypothesize that, because of its unique action as a partial dopamine agonist in brain circuits underlying social cognition, treatment with aripiprazole will lead to a significant improvement in social cognitive processing compared to risperidone.

N/A

80 schizophrenia patients are randomly assigned to either risperidone (4 mg) or aripiprazole (15 mg).