Whether hyperprolactinaemia contributes to exacerbation of psychosis, and whether its effect varies with age and menopause status, is not clear, as research on the topic is scarce and results conflicting.3,7 However, in a recent longitudinal study in first-episode (non-affective) psychosis (FEP), Jordà-Baleri et al demonstrated sex-specific associations: in males, prolactin mediated the relationship between negative symptoms and functional outcome; in females, prolactin negatively correlated with cognitive performance.8 The gene discussed is PRL; the disease is psychotic disorder.