i think i see Tracy's point.
if we went back in time, say, 10,000 years...
We would be unaware of lots of modern vague diseases or conditions.
Being nomadic, hunter gatherers, everyone had addh, and no one could read.
We hadn't yet invented a back-drop; a reference point; from which to judge the mental health of individuals with subtle problems.
Back then, health was different. Life-expectancy was short.
We didn't need to sit still in school and learn math.
If we were incapable of doing that, it wouldn't have raised a blip on the collective radar.
Even color blindness would likely have been mostly irrelevant.
Everyone would have been suffering post traumatic stress.
Saber-toothed tigers would show up at night and eat your baby.
Some of the modern 'ailments' are vague, biologically speaking...
In a way, they are a side-effect of luxury.