PRL and psychotic disorder: Gender (β = 0.27, p<0.0001), type of antipsychotic medication according to potency of inducing hyperprolactinemia (β = -0.23, p<0.003), and the duration of psychosis over 10 years (β = -0.15, p = 0.04) significantly predicted prolactin levels, when age, diagnosis, antipsychotic category (conventional/atypical/combinations of antipsychotics), and BPRS total scores were controlled for.