Effect of Testosterone Replacement Therapy on Cognitive Performance and Depression in Men with Testosterone Deficiency Syndrome

PURPOSE We aimed to evaluate the effect of testosterone replacement therapy (TRT) on cognitive function and depression in men with testosterone deficiency syndrome. MATERIALS AND METHODS We carried out a prospective, placebo-controlled trial involving 106 men with total testosterone levels <3.3 ng/mL and symptoms of hypogonadism. Based on whether the patients received TRT (injection with 1,000 mg testosterone undecanoate) or a placebo (advice to modify lifestyle), the study population was divided into a TRT group (n=54) and a control group (n=52). RESULTS The age among patients in the TRT and control groups was 56.7±12.6 years and 57.8±11.4 years, respectively (p> 0.05). At baseline, no significant differences between the TRT and control groups were noted regarding serum testosterone or prostate-specific antigen levels, or regarding the scores for aging symptoms (Aging Males' Symptoms scale), erectile function (5-item International Index of Erectile Function questionnaire), cognitive function (Korean Mini-Mental State Examination), and depression (Beck Depression Inventory). At 8 months after intervention total serum testosterone levels and erectile function scores had significantly increased (p<0.05), whereas the scores for aging symptoms and depression had significantly decreased (p<0.05) in the TRT group; no significant improvement in any parameters was noted for the control group. Notably, significant improvement in cognitive function was noted among patients with cognitive impairment at baseline (cognitive function score <25) who received TRT. CONCLUSIONS TRT may be considered in men with testosterone deficiency syndrome if low testosterone levels are associated with depression or cognitive impairment.