According to a study in The Hague, the risk for schizophrenia by Moroccan men in the Netherlands is six times greater than by ethnic Dutch, but the risk by women is not significantly higher.
For Moroccans of the second generation, the chance of this psychiatric disorder is 11 times as high than for ethnic members of the same age group. For the second generation the total number of patients was too small in order to draw conclusion about sex differences.
On the other hand, the risk for migrants form Turkey were only slightly higher by men and not high at all for women.
Doctor JP Selten is now running a study to find the cause for these difference.
Source: ZonMw (Study site, Dutch)