Earlier quoted context omitted.
Do you want to discuss this seriously? If so, cite an actual study and say specifically what conclusion it reaches and specifically how that contradicts Szasz. You seem to be implying that Szasz and I hold our positions due to scientific ignorance, which is demonstrably false, and insulting. But maybe you didn't mean it that way.
http://www.szasz.com/manifesto.html > Mental illness is a metaphor (metaphorical disease). The word "disease" denotes a demonstrable biological process that affects the bodies of living organisms (plants, animals, and humans). The term "mental illness" refers to the undesirable thoughts, feelings, and behaviors of persons. Classifying thoughts, feelings, and behaviors as diseases is a logical and semantic error, like…
It says nothing about what inherently is a mental disease and what is not. Perhaps genetic differences causing certain mental "diseases" in average American society (or whatever society in which you conduct a study) actually benefit the individuals in societies with different cultures or structures. In the same way that certain non-psych heritable "diseases" confer some advantages and disadvantages (sickle-cell anemia and malaria, for instance). Fact is, many genetic differences that some people regard as undesirable are not even classified as diseases, even though they have advantages and disadvantages, if not for lifespan, certainly in social mobility within social environments.
tl;dr: it's patently obvious and beneath discussion that in certain genetic differences might lead two otherwise identical individuals to differ on whether they have different behavior, just as they might differ in many other ways. It's the determination that different behavior in some cases is a "disease" that seems to be at the heart of Szasz's critique of psychology.