According to the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders, those experiencing gender identity disorder experience "a persistent and intense distress about assigned sex, together with a desire to be (or insistence that one is) of the other sex. There is a persistent preoccupation with the dress and activities of the opposite sex and repudiation of the individual's own sex."
Jacqueline Hewitt and Campbell Paul, the doctors who run Melbourne's Royal Children Hospital, recently published a review of their clinic's activities in the Medical Journal of Australia.
Since the hospital opened, 39 children have been treated for gender identity disorder, the doctors report. Of these 39, seven of the children have successfully applied to the Family Court for permission to suppress their puberty by use of medication, giving them more time to decide if they wish to undergo further changes to their gender via cross-sex hormone treatment or surgery.
All seven of these children began around 15 and 16 years old their cross-sex hormone treatments, which include extra estrogen treatments for those who wish to be female and extra testosterone treatments for those who wish to be male.
Sex-change surgery is not allowed to occur until age 18 in Australia.
Testosterone treatment for females includes increased muscle bulk, deepening of the voice, stimulated hair growth, and suppression of menstruation, according to the Sydney Morning Herald.
Estrogen treatment includes development of the breasts in males along with a softening and shrinking of the testicles, the newspaper adds.
Many are skeptical of physical solutions to gender identity disorder, arguing that it is a psychiatric problem possibly brought on by environmental factors, and is only worsened by physical interference.
According to the U.S. National Library of Medicine, the cause of gender identity disorder is unknown. The organization claims, however, that "hormones in the womb, genes, and environmental factors (such as parenting) may be involved."
Doctors Paul and Hewitt wrote in their report that all children receive mental evaluations and support during the hormone treatment, and that their clinic has become a main option for children and adolescents seeking cross-sex hormone treatments in Australia.
Dr. Paul told the country's ABC News that there are ethical questions to consider regarding cross-sex hormone treatments, as the long term health and psychological effects are unknown.
"We take that issue very seriously; which is why we have a multidisciplinary, interdepartmental clinic; so we have people from psychiatry, from endocrinology, gynecology, pediatrics," he told ABC News.
The topic of gender identity disorder has been a controversial one, as many have questioned how to deal with young children who claim to be born the wrong gender.
The topic of cross-sex hormone treatment appears to be more accepted in Australia and the United Kingdom.
As previoulsy reported by The Christian Post, Britain's National Health Service (NHS) agreed in Feb. 2012 to fund hormone injections for six gender-confused, pre-adolescent children. These injections would suppress puberty in the children, ages 11 and 12, so they may have time to consider switching sexes.
According to the NHS website, 1 in 4,000 Britons suffers from gender identity disorder. Britain has previously allowed doctors to administer hormone shots to individuals as young as 16, but Feb. 2012 marked the first time that pre-pubescent children were given the shots.
Still, some argue that gender identity disorder is better treated as a psychological issue with therapy alone.
Charles Kane, who spent 100,000 British pounds ($158,000) on sex-change operations to look like a woman before eventually switching back to his male gender, told The Christian Institute in February that what he needed was counseling, not an operation.
"People who think they are a woman trapped in a male body are, in my opinion, completely deluded. I certainly was," Kane said.