Use of high-dose androgens is associated with reduced brain derived neurotrophic factor in male weightlifters

Abstract

Background: Anabolic androgenic steroid (AAS) use causes drastic changes in hormonal milieu and is associated with adverse medical, psychological, and cognitive effects. Brain derived neurotrophic factor (BDNF), a member of the neurotrophin family of growth factors plays a critical role in neuroplasticity, with implications for cognitive function and mental health. Emerging evidence suggests that sex hormones modulate BDNF activities and could be linked to sex differences in the prevalence and clinical characteristics of common mental disorders. The impact of long-term, high-dose AAS on BDNF in a natural setting has not been investigated. This study examined the association between long-term AAS exposure and BDNF levels, and the links between BDNF, heavy resistance exercise, hormones, AAS and mental health.Materials and Methods: We measured serum levels of BDNF and sex steroid hormones in male weightlifters (N=141) with a history of current (n=59), past (n=30) or no (n=52) AAS use. All participants completed questionnaires assessing maximum strength and measures of anxiety and depression. Group differences in BDNF were tested using general linear models adjusting for age, and associations between BDNF and strength, anxiety and depression using Pearson’s or Kendall’s correlations.Results: Both current (mean: 44.2 ng/ml (SD:12.8)) and past (40.0 ng/ml (SD:13.0)) AAS users showed lower serum BDNF levels compared to non-using controls (51.2 (SD: 15.3), p<.001, ηp²=0.10). BDNF levels were negatively related to maximal strength, and with hormonal status in past AAS users, but no significant associations were found with measures of depression and anxiety.Conclusion: Lower BDNF levels in current and past AAS users support a persistent sex-hormonal influence of BDNF activity. Although correlational, the findings raise concern about the long-term consequences of AAS use on neuroplasticity.