It was also believed that gender identity was socially created. In effect they believed that if you raised the boy as a girl and gave him estrogen at puberty, he would never know that he was in fact male. But, almost without exception, the child eventually reverts to being a boy, if that's how he was born. There have been some very good studies and books on a particularly clear example of identical twin boys where one lost his penis in a circumcision accident and was raised solidly and unambiguously as a girl from the first months of life. He is now a middle-aged man with a loving wife and two adopted children.
Gender identity is just as fixed for transsexuals.
Transsexualism doesn't go away. It just doesn't go away. But, it doesn't exist. Now, having said that, there are some very good things about the accepted, standard treatment regimen. First, it is fairly free of risk.