American Psychiatric Association??? What a joke. A bunch of whacked out nutjobs themselves deciding that other whacked out nutjobs are OK? On what basis do they make that determination? Who are they to say this is normal and on what basis?
Simple biology alone tells you it's not. But I guess that's just too obvious for the brainwashed educated elite to figure out.
There is a considerable body of research on which they make that determination. For example, in the 1950s it was assumed that homosexuals are generally very disturbed people, unable to lead productive, stable lives. But the research of Evelyn Hooker, who studied homosexuals in her circle of acquaintances (not homosexuals in treatment or prison), demonstrated that apart from their sexual orientation, homosexuals do indeed live normal, stable lives, often in difficult and demanding professional careers.