Testosterone and the brain

Several studies have found a role for testosterone on cognition (particularly visuo-spatial abilities), mood and depression, and low testosterone values may predict the development of Alzheimer's disease. Testosterone administration to hypogonadal men supports this notion. But not all studies have been able to confirm the association between testosterone and mental functions. These discrepancies might be explained by the large variations in design, inclusion criteria with regard to threshold values of testosterone, duration of study and psychometric instruments. It is likely that men with plasma testosterone values below the lower limit of normal will benefit (most). It is presently not justified to prescribe testosterone as a primary treatment for men with impaired cognitive functioning or mood disorders. These complaints are common in elderly men, and one of the diagnostic considerations might be testing for testosterone deficiency as an etiological factor, and if, upon laboratory measurement, testosterone levels are truly hypogonadal, testosterone treatment is warranted. This probably will not only benefit mental functioning but there will be somatic benefits as well as a result of normalization of testosterone levels.