Sex differences in prolactin levels and clinical outcomes in patients with a first psychotic episode

To analyze the clinical, neurocognitive, and functional impact of prolactin levels according to sex in patients with a First Episode Psychosis (FEP). We measured prolactin levels in 221 non-affective FEP patients treated with antipsychotics (AP) and 224 healthy controls, at baseline and 2-year follow-up. We examined whether the relationships between clinical and functional variables were mediated by prolactin, controlling for antipsychotic use, according to sex. Prolactin levels were higher in patients when compared to controls at both time points. Baseline factors associated with prolactin were chlorpromazine equivalents, attention, and executive functioning. In the FEP group, prolactin levels were associated with functioning and diminished expression in males, and with working memory in females. Prolactin levels (p=0.0134) played a role as a mediator between negative symptomatology (p=0.086) and functional outcome (p=0.008) only in FEP male patients at baseline. Prolactin plays a role in the functionality and clinical symptomatology of FEP patients. Our results suggest that pharmacological counselling in patients with hyperprolactinemia at baseline and negative symptomatology might improve their functional and clinical outcomes. •Prolactin plays a role in the functionality and clinical symptomatology of patients.•Prolactin levels mediated negative symptomatology and functional outcomes in males.•Prolactin was associated with functioning and diminished expression in males.•Prolactin was associated with working memory in females.