Behavioral Effects of Estrogen Treatment in Human Males

Abstract

Human males are exposed to exogenous estrogens in various treatment regimens: (1) Prenatally, (a) if the pregnant mother continues to ingest certain contraceptive steroids, or (b) if she is administered estrogens for pregnancy maintenance; (2) in adolescence and adulthood, when treated (a) for the control of deviant sexual behavior or (b) for demasculinization and feminization in the case of transsexualism; and (3) in midlife or later, when treated for androgen-dependent cancer, especially of the prostate. In spite of the diversity of treatment goals, each regimen provides an experimental model for the investigation of the effects of exogenous hormones on behavior—some of which may be considered undesirable side effects in a risk-benefit analysis of estrogen treatment. In this report, I will briefly review the current status of knowledge with respect to regimens 1, 2, and, to a minor degree, 3. The discussion will focus on sex-dimorphic behavior (i.e., behavior in which males and females typically differ), intelligence, and general psychopathology. In the section on prenatal effects, progestogens will be discussed along with estrogens because both are frequently administered in combination. EFFECTS OF PRENATAL EXPOSURE TO ESTROGENS AND/OR PROGESTOGENS As outlined in another Conference article by Ehrhardt (page 1166), animal research has shown prenatal exogenous estrogens to masculinize sex-dimorphic behavior in the female and to interfere with normal masculinization in the male. This is in contrast to progesterone, which is assumed to have demasculinizing effects in both males and females.1,2 With regard to mental abilities and general psychopathology, I am not aware of any animal models that would allow us to predict effects of prenatal estrogens and/or progestogens in man.