Research looks at differential rates of psychoses by ethnicity

Nov 5 2008

Researchers examining the occurrence of psychoses among migrant groups have shown a raised incidence for all black and ethnic minority subgroups compared with white British counterparts, and reveal that the risk of psychoses for first and second generations varies by ethnicity.

Findings from the East London First Episode Psychosis Study, which recommend that further research should focus on differential rates of psychoses by ethnicity, rather than between generations, are published in the journal Archives of General Psychiatry on 3rd November, 2008.

Led by Professor of Forensic Psychiatry at Barts and The London School of Medicine and Dentistry, Jeremy Coid, and Dr James Kirkbride from the Department of Psychiatry at the University of Cambridge, the research shows that both first and subsequent generation groups in England are at higher risk of schizophrenia and other psychoses (in line with previous literature). Unknown prior to this study, was whether rates were further elevated in second and later generations (i.e. UK born) ethnic minority groups, than in their first generation counterparts.

Professor Coid's and Dr Kirkbride's research suggests that in fact rates are not consistently elevated to a greater extent for later generations (in comparison to the first) but that much depends on the ethnic group in question, and more specifically their age profile. The study, for example, shows incidence rates of psychoses are significantly (statistically) greater for second compared with first generation black Caribbean immigrants, yet their respective age profiles reveal that this is primarily because the second generation are more likely to be in the peak at-risk ages for psychoses (under 30) and that the first generation, having migrated in the 1950s and 1960s whilst in their 20s and 30s, have now moved out of the critical age period of risk for psychoses into their 50s, 60s and 70s.

For other ethnic - such as Asian - groups, rates are elevated among the first generation, who tend to be younger and have migrated to the UK more recently - there are too few second and later generation Asian groups in the sample to detect significantly elevated rates. This is important because it helps to show that while ethnic minority groups are at elevated risk of psychoses compared with the white British, the second generation are not at even greater risk than the first, as speculated by some commentators.

Professor Coid said: "This research shifts the emphasis away from genetics and brain structure to social stress factors experienced by minority groups and the protective factors that buffer them against these stresses. All migrants are at risk of discrimination and other forms of social exclusion and mental health can be adversely affected by these experiences. But why should some minority groups be at greater risk than others? It may be that those who are at greater risk have fewer protective factors. The most likely factors buffering vulnerable persons against social stress include cultural factors relating to that minority group in the population, such as religious and other cultural practices. But family structure is probably the most important protective factor for coping with adverse experiences."