Paraphilia: One of several complex psychiatric disorders that are manifested as deviant sexual behavior. For example, in men, the most common forms are pedophilia (sexual behavior or attraction toward children) and exhibitionism (exposing one's body in a public setting). Other paraphilias include compulsive sexual behavior (nymphomania), sadism, masochism, fetishism, bestiality (zoophilia), and necrophilia. Treatment may include cognitive behavioral therapy, psychotherapy, behavior modification, use of antidepressant medications, and use of medications that alter hormone production, particularly of testosterone. However, the cause and treatment of paraphilia are poorly understood, and treatment is rarely effective. In addition, many professionals prefer not to pathologize sexual behavior that involves only willing adults, even if the behavior might be deemed deviant in mainstream society. In cases where the behavior is potentially criminal, as in pedophilia, treatment is usually delivered within the penal system.