The Role of Testosterone in Sexuality and Paraphilia-A Neurobiological Approach. Part I: Testosterone and Sexuality

Introduction. Antiandrogen therapy has been used for 30 years to treat paraphilic patients and sexual offenders. Yet the therapeutic success of antiandrogens is uncertain. Furthermore, there is still a lack of comprehensive knowledge about the effects of androgen-lowering therapy in paraphilic patients. Aim. This article reviews current neurobiological and clinical knowledge about testosterone and its impact on sexuality, acquired from animal and human basic research. This knowledge may not only enhance our understanding of the great variability of the therapeutic outcome, but could also offer new opportunities to evaluate the effect of androgen-lowering therapy in paraphilia. Methods. A comprehensive review of the human and animal literature is presented, considering the classical and non-classical mechanisms of androgens and the androgen brain receptors. Furthermore, the clinical evidence about the impact of testosterone on human sexual behavior is discussed. These are integrated into two current neurobiological theories of sexual behavior, the four-component model and the dual-control model. Results. The wide distribution of androgen receptors throughout the whole brain and their numerous mechanisms demonstrate that androgens can modulate almost every aspect of sexual behavior-i.e., not only autonomic functions, but also emotional, motivational, and cognitive aspects. Furthermore, testosterone participates in excitatory and inhibitory processes of sexual functions by modulating the activity of mainly dopaminergic neurotransmitter systems. Conclusions. Using the data presented, we combine the two models and present a new integrated approach to understand the role of testosterone in the excitation and inhibition of sexual function, at the neurochemical, neuroanatomical, and behavioral levels. This knowledge will help us to gain a better understanding of the few and inconsistent data that are currently available concerning (i) the association between testosterone and paraphilic behavior; and (ii) the highly variable effects of antiandrogen therapy, discussed in Part II of this review. Jordan K, Fromberger P, Stolpmann G, and Muller JL. The role of testosterone in sexuality and paraphilia-A neurobiological approach. Part I: Testosterone and Sexuality. J Sex Med 2011;8:2993-3007.