Association of DRD2 gene polymorphi̇sms wi̇th akathisia in bipolar and schizophrenia patients treated wi̇th aripiprazole

Aripiprazole is a novel antipsychotic with a unique mechanism of action. Altough it is considered as a safe and well-tolerated, akathisia is reported up to fifteen percent during it' s treatment. Akathisia is a movement disorder that is characterized objectively by an inability to sit or stand still and a subjective feeling of inner restlessness. The mechanisms underlying the occurrence of akathisia during antipsychotic treatment are still not fully understood. The blockade of D2 receptors was hypothesized to cause akathisia. Previous studies had suggested that the Taq 1A and Taq 1B polymorphisms of the dopamine D2 receptor (DRD2) gene is associated with D2 receptor binding and expression in human central nervous system. The aim of the present study was to examine the relationship between DRD2 Taq 1A and Taq 1B polymorphisms and the risk of aripiprazole-induced akathisia. One hundred eight patients with schizophrenia or bipolar disorderwere enrolled into the study. All patients were treated with aripiprazole 10 mg, 15 mg, 20 mg or 30 mg daily dosage. Akathisia was assessed using Barnes Akathisia Rating Scale (BAS). Patients had two or more BAS score were classified as akathisia while the rest were classified as control. Genomic DNA was isolated from peripheral blood samples of the patients. Genotyping was performed by PCR-RFLP analysis. Akathisia was found statisticly higher in B1 allel carriers of DRD2 Taq 1B polymorphism. Our results show that B1 allel of Taq 1B polymorphism may be a risk factor for the ariprazole induced akathisia.