[Role of hormones in sexual dysfunctions, homosexuality, transsexualism and deviant sexual behavior: diagnostic and therapeutic consequences].

Hormones only play a minor role in sexual dysfunctions. They are clearly involved only in erectile dysfunction. Total testosterone is low in 8% of those patients, but only 32% of them are improved with androgen therapy. Free testosterone is also electively decreased in 30% and bioavailable (non SHBG bound) testosterone in 15%. However androgen-therapy is still less effective in these subgroups. Plain hyperprolactinemia is found in only 0,7% of the cases. Half of them result from a pituitary adenoma. The other endocrine dysfunctions are still scarcer. This data cannot justify a systematic determination of serum prolactin and testosterone in sexual dysfunctions. A cost effective hormonal screening is proposed, whereas the role of androgen-therapy in erectile dysfunction with or without hypogonadism is discussed. The hypothesis of an "inverted brain sexual differentiation" in homosexuality and for transsexualism, resulting from an abnormal antenatal endocrine milieu is reviewed. It cannot obviously explain by itself these conditions, but some amazing morphological findings in transsexual people do not permit to totally refute it. Lastly the role of androgens in paraphilia and parapaphilia related disorders seems limited to the arousal of an abnormal sexual behaviour previously scheduled by non hormonal mechanisms. However anti-androgens are in such cases one of the main effective treatment.