Mix effect of prolactin on cognitive performance in patients with schizophrenia.

Prolactin has a wide range of biological functions, including regulation of cognition. However, there are few studies on the relationship between prolactin and cognition in schizophrenia. A total of 113 patients with schizophrenia were included in this study. Serum prolactin concentrations were collected and MATRICS consensus cognitive battery (MCCB) was used for cognitive assessment. Eighty-four of one hundred and thirteen patients (74.3%) had hyperprolactinemia. There was no significant difference in the incidence rate of hyperprolactinemia between different sex (χ2 = 1.57, p = 0.21), but the serum prolactin concentration of female patients was significantly higher than that of male patients (median = 676.5mIU/L for male and median = 1178 mIU/L for female, Z = 2.53, p = 0.001). Inverse U-shaped relationships were found between prolactin and brief visuospatial memory test-revise (BVMT-R) (F = 4.008, p = 0.021); and Hopkins verbal learning test-revised (HVLT-R) (F = 5.857, p = 0.004). Prolactin may have a mixed effect on cognition depending on its concentration and mild elevated prolactin level is beneficial for cognitive performance in schizophrenia.