Hyperprolactinemia in drug-naïve first episode psychosis and its association with BDNF levels

Background and Objectives

Hyperprolactinemia is a common and well-known side effect of antipsychotic treatment. However, prolactin levels are elevated in drug-naïve first-episode psychosis (FEP) patients, which suggests that the association between prolactin and psychosis may be more complex than previously thought. One possible hypothesis to explain this association is that prolactin has a neuroprotective effect mediated by BDNF.

Methods

50 drug- naïve FEP were included and clinical characteristics as DUP; tobacco and cannabis use; and BMI were assessed. The PANSS and GAF questionnaires were administered. Fasting blood samples were obtained to determine prolactin, TSH, and BDNF levels. All statistical analyses were performed in the whole sample and stratified by sex.

Results

Of the 50 patients, 42 % had hyperprolactinemia (33.3 % of males and 55 % of females). Prolactin levels were negatively correlated with baseline GAF scores in the whole sample and in females but not in males. Prolactin levels were positively and independently associated (regardless of sex, age, BMI, TSH level, tobacco or cannabis use) with BDNF levels.

Conclusions

Prolactin secretion may be dysregulated in drug-naïve FEP, which implies that hyperprolactinemia—a common condition in FEP —may not be solely attributable to antipsychotic treatment. Elevated prolactin levels could reflect a physiological response designed to protect the central nervous system in certain critical situations. This neuroprotective effect could be mediated by increasing BDNF levels. Hyperprolactinemia is common in antipsychotic-naïve FEP. This study shows that higher prolactin levels are associated with elevated BDNF levels, suggesting a neuroprotective effect mediated through BDNF in this patient population.