Symptom response and side-effects of olanzapine and risperidone in young adults with recent onset schizophrenia

The symptom response and side-effects of olanzapine and risperidone were compared in patients with recent onset schizophrenia. Actively symptomatic patients (n=44) randomly received olanzapine 15 mg (median dose) or risperidone 4 mg (median dose). Symptom response and side-effects were measured during a 6-10-week treatment study. No major differences were observed between the two treatment groups. Symptoms improved significantly on the Positive and Negative Syndrome Scale total score, positive subscale and general psychopathology subscale for both treatment groups. Using five symptom dimensions, both drugs were effective in treating positive symptoms and agitation/excitement symptoms, and neither olanzapine or risperidone influenced disorganization and depression symptoms. Results on the negative symptoms subscale and symptom dimension were inconclusive. No major differences were found in the frequency of the reported side-effects akathisia, parkinsonism and weight gain. These data indicate that the differences between olanzapine and risperidone in symptom response are small. In spite of the relatively low power of the study, we could exclude the presence of substantially different treatment effects between olanzapine and risperidone.