In discussing sexually dangerous pedophiles, clinicians focus on the concept of paraphilia, from the Greek term meaning 'love of deviation.' The essential feature of disorders in this subclass is the necessity for unusual or bizarre imagery or actions to experience sexual excitement. Pedophilia is a form of paraphilia manifested in an adult who repeatedly and as the preferred or exclusive means of achieving sexual excitement engages in actual or imagined sexual activity with prepubescent children. Pedophiles are typically within the normal range of intelligence, come from all occupational groups, and have the common feature of relative isolation from adult social contact. Those over 20 years old tend to be married, with the exception of homosexual pedophiles, of whom one-third are married. Most pedophiles have personality deficiencies but are not psychotic. As used in the treatment of sex offenders, antiandrogens reduce circulating testosterone, which is associated with the male sexual drive. Since antiandrogens have not yet been approved for use by the Federal Drug Administration, they must be used with volunteer subjects under experimental parameters. Research studies which have been conducted since the 1960's indicate that antiandrogens have reduced male sex drive, decreased the intensity of sexual fantasies, and increased subjects' ability to control dangerous sexual behaviors. Until the long-term effects of antiandrogens have been determined, its administration should not be mandatory.