Is Testosterone a Food for the Brain?

INTRODUCTION: Testosterone is fundamental for psychological, sexological, cognitive, and reproductive aspects, and its lack or reduction largely impacts the quality of life in males and females. AIM: Therefore, the aim of this review is to describe the role of testosterone in the neurophysiology of the brain and related aspects regarding the quality of general and sexual life. METHODS: We listed and discussed the principal studies on the role of testosterone in the brain regarding sexual health, psychopathological conditions, and the elderly. The search strategies were composed by the insertion of specific terms in PubMed regarding the main studies from January 2000 to June 2015. MAIN OUTCOME MEASURES: Using a psychoneuroendocrinologic perspective, we considered 4 main sections: brain and testosterone, sexuality and testosterone, psychopathology and testosterone, and cognitive impairment and testosterone. RESULTS: Much evidence on the neuroendocrinology of testosterone regarding brain activity, sexual function, psychological health, and senescence was found. In any case, it is known that testosterone deficiency negatively impacts quality of life, first, but not exclusively, through a central effect. Moreover, testosterone and androgen receptors are differently expressed according to age and gender. This aspect contributes to gender differences and to the dimorphic physiological role of this hormone. CONCLUSION: A universal role for testosterone can be recognized: low levels of testosterone are associated with mental disorders, sexual dysfunction, and cognitive impairment in both sexes. Hence, physicians should carefully assess testosterone levels, not only in the management of sexual dysfunctions but also when seeking to help patients with severe mental or organic diseases.