Homosexuality was classified as a mental disease prior to DSM IV (might be three. I've had some tragedies in my life recently and I'm still not up to speed again) When it was dropped due to political, NOT MEDICAL, reasons. This is highly documented and you'll find the details in the Homsexual Agenda list of links on Scripters profile page. I believe little jeremiah also posted a link to the list n this thread.
I went over that before with Scripter here some time back. I don't agree it was political. It was medical. There is no medical justification for the claim it's a disease whatsoever. That's why the docs dumped the claim. There's no other reason.