We observed that carriers of at least one COMT rs165815 C allele had lower odds for developing visual hallucinations (OR = 0.34; 95% CI = 0.16–0.72; p = 0.004), while carriers of at least one DRD3 rs6280 C allele and CC homozygotes had higher odds for this adverse event (OR = 1.88; 95% CI = 1.00–3.54; p = 0.049 and OR = 3.31; 95% CI = 1.37–8.03; p = 0.008, respectively). Here, COMT is linked to Visual hallucination.