I believe the USA do have some minor form of mental health / psych eval in most cases. This coming from Botched mind you (and those guys are partly to blame).
That said, where do these people get the money for surgery in the first place, as often these "transformations" are over $100,000+.
However if they can't get something done in the USA they'll just head abroad and get it done.
Down the track there may be another way but right now that's the only effective way to treat it. There will still be those who still kill themselves but the option right now is to either allow them to change or prevent them from changing and increase their risk of suicide and other mental health illness by a large amount.
The problem is that the "want" is greater than the "need" and they are not looking at the whole picture.
Patient: "I want to look like a lizard".
Doctor: "Are you sure"
Patient: "Yes".
*3 months after recovery*
Patient: "I look ridiculous in public everyone stares at me can we undo it"
Doctor: "Yes we can.. but.."
Patient: "But what?"
Doctor: "You spent all your money on the surgery, it will cost twice as much to resolve";
Patient: "Okay no worries, I'll continue being depressed"
*3 months later*
News: In breaking news, Lizardboy has been found with a self inflicted gunshot wound to the head.
The solution isn't surgery, the solution is psychological intervention to make them realise they do not want what they seem to want.
Those that don't end up dead, have done it for the attention in the first place.
I've never been to one of them before.
