Obsessive-compulsive symptoms in patients with schizophrenia: Relationships with olanzapine pharmacological parameters, psychopathology, and quality of life.

Obsessive-compulsive symptoms (OCS) occur in a substantial portion of schizophrenia patients and have significant impacts on clinical course. This study was intended to investigate the relationships of OCS with pharmacological parameters of olanzapine, psychopathology, and quality of life. Totally 151 schizophrenia patients were recruited, and rated using Yale-Brown Obsessive-Compulsive scale (YBOCS), Positive and Negative Syndrome Scale (PANSS), Montgomery-Åsberg Depression Rating Scale (MADRS), and World Health Organization Questionnaire on Quality of Life: Short Form (WHOQOL-BREF). The concentrations of olanzapine and N-desmethylolanzapine were determined by HPLC. Twenty-five patients (16.6%) revealed the presence of OCS. OCS group had significantly higher olanzapine dose, more numbers of past hospitalizations, higher PANSS total, positive, negative, and general psychopathology scores, and higher MADRS score than those in non-OCS group. The WHOQOL-BREF physical subscale score in schizophrenia patients with OCS was significantly lower. Olanzapine dose, PANSS score, and MADRS score were significantly correlated with YBOCS score. Our findings highlight that OCS is highly prevalent in schizophrenia patients under olanzapine treatment, especially those at high doses. Schizophrenia patients with OCS had higher severity of psychotic and depressive symptoms and poorer quality of life. Clinicians should monitor OCS in patients with schizophrenia receiving olanzapine treatment.