Dutch Moroccans are four to five times more likely to be diagnosed with schizophrenia than the white Dutch, according to an Amsterdam University researcher quoted in Wednesday’s Volkskrant.

Psychiatrist Tekleh Zandi says there is no good reason for the more frequent diagnosis apart from a failure to take cultural background into account. Once this has been factored in, there is no difference in diagnosis rates.

For example, the concept of hearing voices – one of the signs used to identify schizophrenia – is more accepted in Moroccan cultures, Zandi writes.

This could be an ‘angry ghost’ or simply remembering something their father said. But it does make it more likely Moroccan Dutch people will tick the ‘hearing voices’ box on a questionaire.

The sample studied was small – 26 Moroccans and 37 white Dutch people. Nevertheless it does raise questions about the idea Moroccan Dutch people are much more prone to schizophrenia, Zandi told the paper.