Neuroendocrine and behavioral effects of high-dose anabolic steroid administration in male normal volunteers

Objective: Despite widespread abuse of anabolic-androgenic steroids (AAS), the endocrine effects of supraphysiologic doses of these compounds remain unclear. We administered the AAS methyltestosterone (MT) to 20 normal volunteers in an in-patient setting, examined its effects on levels of pituitary-gonadal, -thyroid, and -adrenal hormones, and examined potential relationships between endocrine changes and MT-induced psychological symptoms. Method: Subjects received MT (three days of 40 mg/day, then three days of 240 mg/day) or placebo in a fixed sequence with neither subjects nor raters aware of order. Samples were obtained at the ends of the baseline, high-dose MT and withdrawal phases. Potential relationships between hormonal changes and visual analog scale measured mood changes were examined. Results: Significant decreases in plasma levels of gonadotropins, gonadal steroids, sex hormone binding globulin, free T3 and T4, and thyroid binding globulin (Bonferroni t, p < 0.01 for each) were seen during high-dose MT; free thyroxine and TSH increased during high-dose MT, with TSH increases reaching significance during withdrawal. No significant changes in pituitary-adrenal hormones were observed. Changes in free thyroxine significantly correlated with changes in aggressiveness (anger, violent feelings, irritability) (r = 0.5,p = 0.02) and changes in total testosterone correlated significantly with changes in cognitive cluster symptoms (forgetfulness, distractibility) (r = 0.52,p = 0.02). Hormonal changes did not correlate with plasma MT levels. Conclusions: Acute high-dose MT administration acutely suppresses the reproductive axis and significantly impacts thyroid axis balance without a consistent effect on pituitary-adrenal hormones. Mood and behavioral effects observed during AAS use may in part reflect secondary hormonal changes.