Sex influence in hyperprolactinemia incidence has been studied, observing a higher incidence in female than in males, a study of Schoretsanitis et al. [67] involving 111 patients (61 males and 49 females) evaluates association between CYP2D6 activity, risperidone levels and sex finding a significant association across them. This evidence concerns the gene CYP2D6 and hyperprolactinemia.