Compared to the White population the incidence of psychosis among people from the African-Caribbean community living in the U.K. has been estimated as from anything between two and 18 times higher. The reasons for this are not completely clear but some people have suggested that it reflects institutional racism on the part of mental health services who are more likely to diagnose Black people as suffering from psychosis. A team of researchers from the Institute of Psychiatry, King's College London studied 143 people. Half were suffering from their first episode of psychosis and half were healthy controls; within the two groups half were White and half Black. The researchers thought that the Black people diagnosed with psychosis would have less brain abnormalities associated with the condition reflecting the fact that at least some of their diagnoses were due to institutional racism. In fact there were no differences in brain structure between the Afro-Caribbean patients and the White ones and the Afro-Caribbean patients showed a greater loss of grey matter overall than the White ones; showing, that in this sample at least, genuine changes to brain structure may have been behind the diagnoses of the Black patients not just institutional racism. Other conclusions one could draw from this study include: (i) psychosis is a complex social and cultural phenomenon not easily reduced to questions of brain structure (ii) the changes to brain structure observed are the consequences not the causes of psychosis (iii) Afro-Caribbean people aremore vulnerable to psychosis but this is due to poverty, racism, prejudice and, for immigrants at least, isolation and culture shock (iv) Afro-Caribbean people are more vulnerable to psychosis for other reasons. Whatever the theories it will be a long, tortuous and controversial process before the higher rates of psychosis among Black people are properly explained.
Morgan, K.D. ... [et al] - Differing patterns of brain structural abnormalities between black and white patients with their first episode of psychosis Psychological Medicine July 2010, 40(7), 1137-1147