Western Schizophrenia Tests Overdiagnose Immigrants

New research suggests that it’s not that immigrants have higher rates of schizophrenia, but rather that our tests for schizophrenia are biased

Joe Skinner Photography

Statistically, immigrants are more likely to have schizophrenia. In Denmark, the rates of schizophrenia are 5 to 12 times higher in the Greenland Inuit immigrants. Moroccan men who move to the Netherlands are at a seven times higher risk of schizophrenia than native Dutchmen. Afro-Carribeans in England are nine times more likely to have schizophrenia. The statistics go on. But new research suggests that it’s not that these people have higher rates of schizophrenia, but rather that our tests for schizophrenia are biased to overly diagnose immigrants. 

According to Eva de Lozanne at United Academics, “standardized test may overdiagnose immigrants due to cultural misinterpretation.” Not only do most doctors not know the cultural norms of the patients they’re testing, they often try to keep it that way, to prevent assumptions. But this could backfire, if cultural understandings impact how people take these kinds of tests. De Lozanne explains:

Researcher Tekleh Zandi suspected that immigrants may be overdiagnosed as schizophrenic as a result of different interpretations of the disease’s symptoms. Specifically hearing voices as well as experiencing dissaociation may actually be more susceptible to cultural interpretation than one may think at first.

Scientists have tried to figure out just how bad schizophrenia tests are at accounting for cultural differences. In one study they gave 26 Moroccan and 26 Dutch subjects two tests — one normal and one culturally sensitive. Thirty months later, they called the same subjects back and gave them the same two tests. The Dutch subjects answered the tests the same way both times. But the diagnostic stability between the first and second tests for the Moroccan subjects was only 27 percent. “That Morrocan patients were often ‘cured’ after 30 months is odd, considering the usually chronic character of schizophrenia.” On the other hand, the culturally sensitive test saw the same diagnostic consistency for both Dutch and Moroccan subjects. 

Other studies have also suggested that culturally sensitive tests can close the gap between native and immigrant diagnoses when it comes to schizophrenia. Which suggests that doctors should lift their cultural blinders for a bit. 

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