Actually, schizophrenia appears to be one of the few mental illnesses -- maybe the only one -- to affect all cultures almost equally. Schizophrenics can be found in small African villages, Chinese industrial centers, Tibetan mountain villages, and of course in the West.

There's some variation in the respective prevalence of certain symptoms across cultures (catatonia is more common in non-western cultures, for example), but the cluster of symptoms defined as schizophrenia in the DSM has been found in almost every culture known to man (I believe symptoms of schizoprenia have even been found among some people from the Yamomamo indigenous tribe of the Amazon).

My knowledge of this comes from graduate and undergrad psychology, neuroscience and global public health courses -- I'm definitely not a psychologist or psychiatrist. But I am somewhat skeptical of the study you posted. I suppose it's possible that prevalence of schizophrenia might be somewhat higher in urban environments, but there's pretty overwhelming evidence that schizophrenia occurs across cultures in similar proportions.

There have been many, many published studies on this phenomenon. Here's one:

https://blogs.commons.georgetown.edu/journal-of-health-scien...