Quite so.
A great deal of research in medicine and psychology has been carried out mostly on white First World citizens. That has to be a handicap to generalizability.
Human psychology is human psychology, we still have the same brains, and those brains are prone to the same set of malfunctions. The example of anorexia in HK, even though the original cases were somatic, they still existed (although they were expressed differently). There's several things that could cause it in addition to simple societal pressures. The likely rise of anorexia in Hong Kong during the 90's could very well have been a result of increasing amounts of "thinner is better" social pressures.
A couple quick examples from the article:
In some Southeast Asian cultures, men have been known to experience what is called amok, an episode of murderous rage followed by amnesia;
This sounds quite a bit like having two different personalities.
men in the region also suffer from koro, which is characterized by the debilitating certainty that their genitals are retracting into their bodies
This is not culture specific, I've heard of exactly this same thing in Africa (where they believe a witch/warlock put a spell on them so they have their families take turns holding onto it while they sleep). What do these areas have in common? Often bad education and rampant superstion.
Across the fertile crescent of the Middle East there is zar, a condition related to spirit-possession beliefs that brings forth dissociative episodes of laughing, shouting and singing.
Classic bi-polar. One minute you're normal, the next minute you can't control yourself.
EDIT: Correction, probably more like just "manic". I could be mistaken though, but it is better to ask a professional.
I'm not a psychologist by anymeans, but

of this sounds really fishy.