'Perceived disadvantage' may explain the higher rates of psychosis found among Black people living in the UK, a new study has found.

The Aetiology and Ethnicity in Schizophrenia and Other Psychoses (AESOP) study has confirmed that levels of psychosis are significantly higher in African-Caribbean and Black African people living in the UK, compared with the White British population.

In this study, published in the March 2008 issue of the British Journal of Psychiatry, the researchers distinguished between people's perception of disadvantage, and what they thought was the reason for it (for example, discrimination, mental illness, or personal failings).

AESOP is a population-based study of first-episode psychosis among people aged 16-65 living in the Nottingham area and in South-East London. In this study, 482 participants were asked the question, 'Do you believe that you experience any disadvantage when compared with other individuals in British society?' This group was compared with a control group of people without psychosis.

Those answering 'partly' or 'yes' to the question were asked to rate the degree to which they thought this was due to their skin colour; to their culture, cultural beliefs or religion; or to their social class. Participants were assessed for psychotic symptoms and for self-esteem.

It was found that people with psychosis were younger, more likely to be unemployed, to belong to a Black ethnic group, to have left school at age 18 or before, to come from social class V (unskilled), and to have some form of religious affiliation.

The analysis in this paper was designed to distinguish, if possible, between two potential explanations for the excess of psychosis in black members of the British population. One explanation is that discrimination induces a mindset characterised by a tendency to attribute personal disadvantage to the machinations of others, machinations driven for instance by racism. In extreme cases this mindset might cross the boundary into the frank paranoia that characterises psychosis.

The other possible explanation is that people who internalise disadvantage as self deprecation are more prone to develop psychosis.

We found that study participants in the Black non-psychosis group did indeed often attribute their disadvantage to racism, whereas their counterparts in the psychosis group attributed it to their own situation. When asked to comment on the reasons for their disadvantages, people with psychosis referred more frequently than controls to lack of support at school or home, their own lack of confidence, attitudes, behaviour or physical appearance, and bad luck.

Thus the results suggest that a minor degree of paranoia might even protect people from ethnic minority backgrounds from psychosis, perhaps by fostering community cohesion. However, low self-esteem, possibly indicating depression, was clearly linked to psychosis. Those perceiving greater disadvantage had significantly poorer self-esteem and had a poorer view of themselves.

The researchers also concluded that the greater disadvantages perceived by Black people were not due either to psychotic symptoms or to negative self-perceptions, but probably due to actual discriminatory experiences.

If people who experience more disadvantage really are more prone to psychosis, it would have important consequences both for primary prevention and for treatment, say the researchers.

However, people with psychosis are more likely to perceive that they are disadvantaged in society than healthy people, even after taking into account ethnicity, social class and other socio-economic factors.

Few people in this study attributed the disadvantage they felt to mental illness or racism; they were more likely to mention their appearance and behaviour, or lack of support. A long-term study is needed to determine exactly what causes what.

Reference

Perceptions of disadvantage, ethnicity and psychosis
Cooper C, Morgan C, Byrne M, Dazzan P, Morgan K, Hutchinson G, Doody GA, Harrison G, Leff J, Jones P, Ismail K, Murray R, Bebbington PE and Fearon P
British Journal of Psychiatry, 192, 185-190.

Royal College of Psychiatrists