Dimensions of schizophrenia and their time course of response to a second generation antipsychotic olanzapine-A clinical study.

Background: The pattern of symptom response to second generation antipsychotics (SGAs) has not been studied extensively. Understanding the time course of symptom response would help to rationally monitor patient progress.

Objective: To determine the short-term differential time course of response of symptom dimensions of first episode schizophrenia viz., negative, positive symptoms and 5 factors of anergia, thought disturbance, activation, paranoid-belligerence and depression to treatment with SGA olanzapine.

Methods: 57 drug naive patients with schizophrenia were treated for 4 weeks with olanzapine 10mg/day, increased to 20mg/day in 1 week. Weight was recorded and ratings with the Positive and Negative Syndrome scale (PANSS), the Simpson Angus Scale (SAS) were performed weekly.

Results: 43 patients completed 4 weeks of assessment. Scores on all of the dimensions improved. By the end of week 1, only positive syndrome, thought disturbance and paranoid-belligerence dimensions improved. Maximum improvement was seen with paranoid-belligerence by week 1, followed by positive syndrome in week 2, and depression at week 3. The percentage improvement in positive syndrome was significantly greater than negative. Over 4 weeks there was a mean weight gain of 2kg and there were significant extrapyramidal symptoms.

Conclusions: Olanzapine produced reduction in all dimensions, but the pace of responding of individual dimensions differed. Longer-term studies comparing SGAs with first generation antipsychotics are needed.