Only the second and fourth paragraph of this response are "important". The rest is an attempt at clarification of my personal viewpoint. I'm doing my absolute best to not offend people on a very touchy subject - but I know it is inevitable to do so. For that, I apologize for holding a different opinion but ask that you read the entire response to understand the reasoning behind my position.

[Paragraph the second] The declassification of homosexuality as a mental disorder had more to do with harassment of the APA for several years leading up to 1973 by advocate groups than it does scientific consensus. Scientists are afraid to speak on the issue due to harassment and the possibility of losing their jobs due to said advocate groups. Even so much as trying to conduct studies on SOCE would get you harassment nowadays if the public was aware.

If we are to consider reproduction and the continuation of a species to be what is "normal" for a species (ie. the goal of a species is to produce a generation to succeed it to avoid extinction) then homosexuality is a disorder. Homosexuals cannot reproduce naturally and only through scientific advances can they choose to have a surrogate mother or a sperm donor to have a child: which is from a heterosexual process.

[Paragraph the fourth] The issue that arises of classifying it as a mental disorder is the stigma people attach to people with mental disorders. This stigma can be harmful to people and thus should be avoided. Regardless of scientific accuracy - I approve of any effort to treat people more humanely and if that means not considering a deviation from the norm to be a disorder, than so be it. I would like to point out that not all mental disorders have equivalent social stigma attached. OCD and insomnia don't tend to get someone harassed - while being anti-social or autistic is more likely to get someone harassed.

The definition of "mental disorder" is a mental condition that negatively impacts the person with the disorder. It's not clear (due to poorly conducted studies [0]) whether homosexuality is a disorder or if societal pressures are the cause of an increased number of suicides and depression. Until the social stigma goes away, I don't think we can find an answer on this. My intuition tells me that the increased amount of stress/depression/suicide are all strongly correlated with social stigma and that in more progressive and accepting regions these negative feelings are more rare. But my intuition and science don't always agree, so I've learned to not trust my intuition.

My personal views are closely related to Havelock Ellis [1].

>He proposed that being “exclusively homosexual” is to be deviant because the person is a member of a minority and therefore statistically unusual, but that society should accept that deviations from the "normal" were harmless, and maybe even valuable. Ellis believed that psychological problems arose not from homosexual acts alone, but from when someone "psychologically harms himself by fearfully limiting his own sex behavior.

TFL;DFR: It doesn't matter if it is or isn't. What matters is that society works to remove the stigma attached and treat each other humanely.

[0] http://www.apa.org/pi/lgbt/resources/therapeutic-response.pd...

[1] https://en.wikipedia.org/wiki/Homosexuality_and_psychology