Classifying homosexuality as a mental disorder has a good level of objectivity and that’s why I’ll explain this view before concluding whether it is helpful or pointless. I’m also sorry that the word ‘disorder’ has a bad stigma to it while in fact ‘disorder’ is just what is different from what we subjectively consider ‘order’.
Mental or personality disorders, such as psychopathy, are the behaviors driven from the brain of the individual handling certain values. They’re almost all contributed to the individual having susceptible genetics and environmental variables that default the brain to those behaviors during its developing years. There are also drugs that stimulate those mental disorders temporarily. Unfortunately however, there is no counter drug that neutralizes every mental or personality disorder.