PA-1
Effects of olanzapine on plasma levels of catecholamine metabolites, cytokines, and brain-derived neurotrophic factor in schizophrenic patients

Hikaru Hori, Reiji Yoshimuta, Yasuhisa Yamada, Atsuko Ikenouchi, Masae Mitoma, Yoshishige Ida, and Jun Nakamura

Department of Psychiatry, Univ. of Occup. and Envir. Health

Olanzapine, an atypical antipsychotic agent like clozapine and risperidone, was introduced into clinical practice, and placebo-controlled studies have shown that olanzapine is effective in reducing positive symptoms and there is increasing evidence that olanzapine is effective in treating negative symptoms. In the present study, we investigated the effects of olanzapine on plasma levels of catecholamine metabolites, brain-derived neurotrophic factor, and cytokines 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 MHPG levels, which were associated with the changes in the total scores of negative symptoms measured on the Positive and Negative Symptoms Scale (PANSS), and decreased the plasma HVA levels. In addition, treatment with olanzapine for 8 weeks reduced the plasma IL-2 levels. In contrast, olanzapine did not alter the plasma levels of BDNF, IL-6, or TNFα. These results suggest that olanzapine influences of catecholamine metabolites and IL-2, which might be associated with its clinical efficacy. However, since most patients had been treated with conventional and atypical antipsychotic drugs before olanzapine administration, the effects of those antipsychotic drugs on plasma levels of catecholamine metabolites, cytokines, and BDNF might not be ruled out. Therefore, further studies are warranted to confirm our preliminary results.