Effects of olanzapine on plasma levels of catecholamine metabolites, cytokines, and brain-derived neurotrophic factor in schizophrenic patients.

In the present study, we examined the effects of olanzapine on plasma levels of catecholamine metabolites, brain-derived neurotrophic factor, and cytokines (interleukin-2, interleukin-6 and tumor necrosis factor-alpha) using 32 olanzapine-treated schizophrenic patients and age and sex-matched 55 healthy individuals. Treatment with olanzapine for 8 weeks improved both positive and negative symptoms of schizophrenia. It also increased the plasma 3-methoxy-4-hydroxyphenylglycol levels, which were associated with the changes in the total scores of negative symptoms measured on the Positive and Negative Symptom Scale, and decreased the plasma homovanillic acid levels. In addition, treatment with olanzapine for 8 weeks reduced the plasma interleukin-2 levels. In contrast, olanzapine did not alter the plasma levels of brain-derived neurotrophic factor, interleukin-6, or tumor necrosis factor-alpha. These results suggest that olanzapine influences the dynamics of catecholamine and interleukin-2, which might be associated with its clinical efficacy.