Females with Gender Identity Disorders generally experience less ostracism because of cross-gender interests and may suffer less from peer rejection, at least until adolescence. In child clinic samples, there are approximately five boys for each girl referred with this disorder. In adult clinic samples, men outnumber women by about two or three times. In children, the referral bias towards males may partly reflect the greater stigma that gross-gender behavior carries for boys than for girls.
There are no recent epidemiological studies to provide data on prevalence of Gender Identity Disorder. Data from smaller countries in Europe with access to total population statistics and referrals suggest that roughly 1 per 30,000 adult males and 1 per 100,000 adult females seek sex-reassignment surgery.
For clinically referred children, onset of cross-gender interests and activities is usually between ages 2 and 4 years, and some parents report that their child has always had cross-gender interests. Only a very small number of children with gender Identity Disorder will continue to have symptoms that meet criteria for Gender Identity Disorder in later adolescence or adulthood. Typically, children are referred around the time of school entry because of parental concern that what they regarded as a phase does not appear to be passing. Most children with Gender Identity Disorder display less overt cross-gender behaviors with time, parental intervention, or response from peers. By late adolescence or adulthood, about three-quarters of boys who had a childhood history of Gender Identity Disorder report a homosexual or bisexual orientation, but without concurrent Gender Identity Disorder. Most of the remainder report a heterosexual orientation, also without concurrent Gender Identity Disorder. The corresponding percentages for sexual orientation in girls are not known. some adolescents may develop a clearer cross-gender identification and request sex-reassignment surgery or may continue in a chronic course of gender confusion or dysphoria.
In adult males, there are two different courses for the development of Gender Identity Disorder. The first is a continuation of Gender Identity Disorder that had an onset in childhood or early adolescence. These individuals typically present in late adolescence or adulthood. In the other course, the more overt signs of cross-gender identification appear later and more gradually, with a clinical presentation in early to mid-adulthood usually following, but sometimes concurrent with, Transvestic Fetishism. The later-onset group may be more fluctuating in the degree of cross-gender identification, more ambivalent about sex-reassignment surgery, more likely to be sexually attracted to women, and less likely to be satisfied after sex-reassignment surgery. Males with Gender Identity disorder who are sexually attracted to males tend to present in adolescence or early childhood with a lifelong history of gender dysphoria. In contrast, those who are sexually attracted to females, to both males and females, or to neither sex tend to present later and typically have a history of Transvestic Fetishism. If Gender Identity Disorder is present in adulthood, it tends to have a chronic course, but spontaneous remission has been reported.