Influence of CYP2D6 polymorphisms on symptomatology and side-effects of patients with schizophrenia in Malaysia.

BACKGROUND Our objective was to investigate the association of CYP2D6 polymorphisms with symptoms and side-effects of patients with schizophrenia. METHODS The subjects were 156 patients with schizophrenia undergoing antipsychotic treatment at a psychiatric clinic. Patients with co-morbid diagnoses of substance abuse or mental retardation were excluded from the study. Psychopathology was evaluated using the Positive and Negative Symptoms Scale (PANSS). Extrapyramidal side-effects and akathisia were assessed with the Simpson Angus Scale (SAS) and the Barnes Akathisia Rating Scale (BARS), respectively. DNA was extracted from blood and subjected to PCR-genotyping. RESULTS We found that CYP2D6 polymorphisms were significantly associated with a subtotal negative PANSS score. In addition, CYP2D6 is not related to side-effects of antipsychotic therapy, or SAS and BARS scores. The results suggest that CYP2D6 polymorphisms may have implications in treatment response. CONCLUSIONS Therefore, CYP2D6 may be a predictor for treatment outcomes of patients with schizophrenia. However, further investigation is required to confirm these findings in a larger sample.