The "science" here has absolutely been affected by decades of lobbying and coercion.
> In 1973, after intense lobbying by gay and lesbian groups and new scientific information from researchers like Evelyn Hooker and Kinsey, the APA declassified homosexuality as a mental disorder[33] with a vote of 58% of the membership supporting the measure. [0]
I'm not saying that every lobbying effort was wrong - but you have to admit a couple things here:
1. Topics that are surrounded by controversy are way more susceptible the effects of political agendas. [1]
2. Psychology is a soft science. [2] So, it's even more susceptible.