MicroRNA-195 predicts olanzapine response in drug-free patients with schizophrenia: A prospective cohort study

Disturbances of microRNA-195 have been implicated in the pathogenesis of schizophrenia. However, microRNA-195 levels in schizophrenia are controversial.

To the best of our knowledge, this is the first study to examine microRNA-195 levels in untreated schizophrenia patients and their relationship to olanzapine response.

We recruited 81 untreated schizophrenia patients and 96 healthy controls. The patients received 2 months olanzapine treatment. MicroRNA-195 levels in peripheral blood mononuclear cells were measured using quantitative real-time polymerase chain reaction testing. Psychiatric symptoms were assessed using the Positive and Negative Syndrome Scale.

No significant differences in microRNA-195 levels were found between patients and healthy controls (p > 0.05). Olanzapine significantly reduced microRNA-195 levels after 2 months treatment (p = 0.003). Interestingly, microRNA-195 levels decreased significantly in responders (p = 0.010), but not in non-responders (p > 0.05). Both baseline microRNA-195 levels (p = 0.027, p = 0.030) and the reduction rate of microRNA-195 levels (p = 0.034, p = 0.044) were positively associated with the reduction rate of Positive and Negative Syndrome Scale total score and general psychopathological subscale score. Multiple stepwise regression analysis revealed that baseline microRNA-195 level was an independent contributor to the reduction in Positive and Negative Syndrome Scale total score and the general psychopathological subscale score (p = 0.018, p = 0.030). Finally, logistic regression analysis suggested that baseline microRNA-195 level can serve as a biomarker for response to olanzapine (p = 0.037).

Our data indicate that microRNA-195 level may predict symptomatic improvement and olanzapine response in schizophrenia patients, suggesting that microRNA-195 should be considered as a potential therapeutic target for antipsychotics.