No association of antipsychotic agent-induced weight gain with a DA receptor gene polymorphism and therapeutic response.

AIM: To investigate whether there is an association of antipsychotic agent-induced weight gain with the TaqI A polymorphism of dopamine D2 receptor (DRD2) gene and therapeutic response to antipsychotic treatment in schizophrenia.

METHODS

Genotyping was performed using the PCR-RFLP techniques in a total of 117 first-episode Chinese Han schizophrenic patients (mean age 26+/-8 a; 58 male, 59 female). Moreover, the measurements were finished either for baseline weight and body mass index (BMI) or for changed weight and BMI 10 weeks after antipsychotic treatment. The Positive and Negative Symptom Scale (PANSS) was used for the evaluation of the improvement of clinical psychotic symptoms.

RESULTS

There was an average increase in body weight of (3+/-3) kg or (6+/-6) % of baseline weight with a changed range of -7 kg - 12 kg or -7.8 % - 32.4 % 10 weeks after treatment, and the change in the BMI was associated with the baseline BMI and patients' age (P=0.0001; P=0.03; respectively). However, there was no significant difference in distribution of allelic frequencies (X2=0.65, v1, P>0.05) and genotype (x2=1.47, v2, P>0.05) between the subgroups, and the change in BMI was not associated with genotypes of DRD2. Furthermore, there was no relationship of the therapeutic response to antipsychotic treatment with changed BMI in the patients (P>0.05).

CONCLUSION

The TaqI A polymorphism of DRD2 gene is therefore unlikely to play an important role in antipsychotic agent-induced weight gain, a side effect of antipsychotic treatment. Furthermore, increase in body weight is unlikely to be prediction of therapeutic response to antipsychotic treatment in schizophrenia.