Improvement in social functioning in outpatients with schizophrenia with prominent negative symptoms treated with olanzapine or risperidone in a 1 year randomized, open-label trial

Abstract

GENERAL PURPOSE: To evaluate the social functioning of schizophrenic outpatients after switching to second-generation antipsychotics.

Methodology: Multi-center, randomized, open-label, parallel, flexible-dose, 1-year study of schizophrenic outpatients with prominent negative symptoms (defined as a SANS Global score > or =10), previously treated with conventional antipsychotics. Patients were randomly assigned (1:1 ratio) to treatment with an initial dose of at least 10 mg/day olanzapine (N = 120) or at least 3 mg/day risperidone (N = 115). Dosage could be modified during the study according to clinical criteria. Social functioning was evaluated using the total and subscales scores of the Social Functioning Scale (SFS) (validated Spanish version). Other efficacy measures included the SANS, SAPS, and CGI-S scales. Response was defined in advance as a 30% improvement in the SANS Global score.

Results: The mean doses during the trial were 12.2 mg/day (S.D. = 5.8) of olanzapine and 4.9 mg/day (S.D. = 2) of risperidone. There were no significant baseline differences in SFS total scores or other relevant clinical variables. At 1 year, olanzapine-treated patients presented a mean improvement in SFS total scores (7.75) that were significantly higher (p = 0.0028) than for risperidone-treated patients (-0.92). Treatment with olanzapine resulted in a greater numerical improvement than risperidone in all SFS domains and reached statistical significance in such categories as social engagement or withdrawal (p = 0.01), independence (performance) (p = 0.0098), independence (competence) (p = 0.04), recreational activities (p = 0.0391), and occupation/employment (p = 0.0024) in which the greatest difference between the olanzapine and risperidone groups was found (0.86 vs. -3.06). Significantly more patients treated with olanzapine reached or surpassed the SFS typified total scores corresponding to a functional level that is representative of a sample of stabilized Spanish outpatients with schizophrenia without prominent negative symptoms (p = 0.0009). Associated factors were treatment with olanzapine and a 30% improvement or more in SANS global score or SAPS global score.

Conclusions: Long-term treatment with olanzapine was associated with overall greater improvement in social functioning (as measured by SFS) compared to risperidone-treated patients.