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.