First off -- how much do you know about psychology?
Homosexuality only leads to depression and emotional discomfort because it's not widely accepted in society. People will hide who they really are for fear of being discriminated against, and THIS is what leads to people becoming depressed and anxious. And it's ridiculous that so many people have to stay silent about who they are and suffer emotionally because they're forced to live a lie out of fear of persecution.
Just because a sexual behavior is considered deviant doesn't make it abnormal; and these definitions change constantly. Things that were thought to be odd 20 years ago aren't anymore.
Ahh, but people don't have sex simply for reproduction. They do it for enjoyment as well, and I'd say that two gay men or women can succeed in that. Therefore homosexuality isn't necessarily dysfunctional.