My theory is that people with the mental and physical disorders measured in this study are more likely to regularly partake in activities that develop and accen

My theory is that people with the mental and physical disorders measured in this study are more likely to regularly partake in activities that develop and accentuate traits that are used to measure IQ throughout their lives in order to cope with social exclusion and loneliness, starting from an early age. This social exclusion can come in the form of peer rejection, voluntary solitary withdrawal, or a combination of both. If you're ugly, depressed, have an anxiety disorder, a personality disorder, or anything else that precludes you from engaging with other people and participating normally in "real life", you're going to spend more time resorting to escapism. If your form of escapism is something that contributes to a marketable skill later in life, and you engage in it from a very early age, then I think that this would correlate with a higher IQ, depending on the tests administered. Things like reading (books or the internet), videogames (certain ones), music, art, math, and programming of course.