Possible genetic biomarker associated with antipsychotic-induced amenorrhea in female patients with schizophrenia

This study explored the association of pharmacogenomics with antipsychotic-induced amenorrhea in female patients with schizophrenia. A total of 89 female schizophrenia patients aged 18-40 receiving consistent antipsychotics at a consistent dose for more than 3 months were enrolled in this study. Amenorrhea was defined as the absence of menstrual period for 3 months or three periods in a row. Serum levels of prolactin, estradiol, follicle-stimulating hormone, luteinizing hormone, and thyroid-stimulating hormone were measured and Cytochrome P450 2D6, dopamine receptor D2 (DRD2) and estrogen receptor 1 were genotyped. Twenty-two patients with amenorrhea had higher prolactin levels and lower estradiol levels than those without amenorrhea (94.1 vs. 71.5 ng/ml for prolactin; P = 0.044 and 27.0 vs. 46.7 pg/ml for estradiol; P = 0.007, respectively). Multiple logistic regression analysis identified DRD2-141C deletion [odds ratio (OR) = 1.71, 95% confidence interval (CI) = 1.01-4.17; P = 0.049] and drugs increasing prolactin levels (OR = 6.17, 95% CI = 1.28-29.64; P = 0.023) as significant covariates for antipsychotic-induced amenorrhea. This study suggests that DRD2-141C deletion is associated with antipsychotic-induced amenorrhea although further studies are needed.