Department of Mental Health Services, University College London
Institute of Psychiatry, London
Department of Psychology, University of Westminster, London
Psychiatry Unit, Department of Clinical Medical Sciences, University of the West Indies, Champs Fleurs, Trinidad
University of Nottingham, Nottingham
Academic Unit of Psychiatry, Cotham House, Bristol
Department of Mental Health Sciences, University College London
Department of Psychiatry, University of Cambridge, Addenbrookes Hospital, Cambridge
Institute of Psychiatry, London
Department of Mental Health Sciences, University College London
Institute of Psychiatry, London, UK
Correspondence: Professor Paul Bebbington, UCL Department of Mental Health Sciences, Charles Bell House, Riding House Street, London W1W 7EY, UK. Email: p.bebbington{at}ucl.ac.uk
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People from Black ethnic groups (African–Caribbean and Black African) are more prone to develop psychosis in Western countries. This excess might be explained by perceptions of disadvantage.
Aims
To investigate whether the higher incidence of psychosis in Black people is mediated by perceptions of disadvantage.
Method
A population-based incidence and case–control study of first-episode psychosis (Aetiology and Ethnicity in Schizophrenia and Other Psychoses (ÆSOP)). A total of 482 participants answered questions about perceived disadvantage.
Results
Black ethnic groups had a higher incidence of psychosis (OR= 4.7, 95% CI 3.1–7.2). After controlling for religious affiliation, social class and unemployment, the association of ethnicity with psychosis was attenuated (OR=3.0, 95% CI 1.6–5.4) by perceptions of disadvantage. Participants in the Black non-psychosis group often attributed their disadvantage to racism, whereas Black people in the psychosis group attributed it to their own situation.
Conclusions
Perceived disadvantage is partly associated with the excess of psychosis among Black people living in the UK. This may have implications for primary prevention.
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Direct racist attack is less common than perceived discrimination in interpersonal interactions.5 Using data from a large, cross-sectional national survey in Sweden, Wamala et al demonstrated that perceived discrimination, defined as unfair treatment that results in humiliation, was associated with psychological distress.6 Veling et al demonstrated that the rates of self-reported discrimination among people living in a Dutch city were higher among people from non-Western ethnic groups (mainly people originating from Surinam, Turkey and Morocco) compared with those from Western ethnic groups, and that this partially explained the greater likelihood of psychosis in the non-Western ethnic groups.7
In this study we distinguish between the perception of disadvantage and its attribution (for instance, to discrimination, to mental illness or to personal failings). We primarily aimed to use data from the ÆSOP study in order to test the hypothesis that the increased incidence of psychosis among Black people living in the UK is mediated by higher rates of perceived disadvantage. We also explored participants own accounts of the reasons for perceived disadvantage, including whether they attributed this to mental illness. Our second hypothesis was that reporting higher levels of disadvantage would be more common in people with psychosis after taking account of ethnic status and other socioeconomic factors. Finally, we investigated whether there was an association in people with psychosis between perceived disadvantage and (first) self-esteem and self-concept, and (second) psychotic symptoms. The purpose of this was to explore whether the association between psychosis and perceived disadvantage might be accounted for by low self-esteem and poor self-concept or by psychotic symptoms such as delusions of persecution or reference.
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A random population-based sample of control participants was selected using the sampling frame preferred by the Office of Population and Census Statistics Psychiatric Morbidity Survey, namely the Postal Address File.9 The Postal Address File was used to generate a random sample of ten target addresses in relation to each case, from which controls were recruited. Each address was contacted three times (morning, afternoon, evening) to find eligible and willing control participants aged 16–65 years. This method matches cases and controls by area of residence. Cases and controls were otherwise unmatched, the aim being to select a sample of controls representative of the population from which the cases were drawn. Candidates for the control group were excluded if they screened positive for psychosis on assessment with the Psychosis Screening Questionnaire.10 African–Caribbean controls were oversampled to ensure sufficient numbers.
During the study period 535 cases (330 in south-east London, 205 in Nottingham) and 391 controls (183 in south-east London, 208 in Nottingham) were identified, a total of 926 participants; the response rate for the main study was 66% (see earlier ÆSOP papers for more details of the study).11,12 Five hundred and seventeen participants–41.9% (n = 224) of cases and 74.9% (n = 293) of controls–completed the questions on disadvantage. Of these, we included those from the Black (Black Caribbean n = 108, Black African n= 32, Black other n = 2; total n = 142) and White (British n= 305, Irish or other n = 35; total n = 340) ethnic groups in the current study.
Measures
Data on ethnicity, gender, age and social class were collected using the
Medical Research Council Socio-demographic
Schedule.13
Ethnicity was based on participant self-ascription using 2001 census
categories. Social class was based on the participants highest-level
occupation in 1990, or their fathers last occupation if they had never
worked. We also extracted data on the highest educational level attained
(school, further, higher); whether participants were born in the UK or not;
employment status (coded as employed, unemployed, other); religion (coded as
Christian, Muslim, other and none); and recruitment centre (London or
Nottingham).
The Culture and Identity Schedule–2 (CANDID–2) questionnaire, developed from an earlier instrument,14 explores the attitudes and perceptions of participants to life in the UK today. As part of this questionnaire participants were asked, Do you believe that you experience any disadvantage when compared with other individuals in British society? and requested to rate their answers on a Likert scale from 1 (no), 3 (partly) to 5 (yes). Those rating their answers 2–5 were then asked to rate, also on five-point Likert scales, 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, and invited to make additional comments about possible reasons. They were asked what else might be responsible for the disadvantage that they experienced. Answers were recorded verbatim, and subsequently classified by one of the authors (C.C.) according to the type of reason given. Finally, respondents were asked, What do you think determines your social class? Interviewers then probed for the responses: family background, education, race, address, culture, clothing, accent, wealth or income. All determinants listed by the participants were recorded.
Patients were interviewed using the World Health Organization (WHO) Schedules for Clinical Assessment in Neuropsychiatry (SCAN) version 2.1.15 A total symptom score was obtained by summing the SCANs individual symptom item scores, as per Wing & Sturts procedure for the Present State Examination.16 Scores for persecutory delusions, delusions of reference and other non-affective delusions, and for auditory hallucinations were analysed as below threshold (score 0), present and associated with moderate disability (score 1) or present with severe disability or distress (score 2). Participants also completed the Rosenberg Self-Esteem Scale,17,18 a ten-item questionnaire with items rated on a four-point Likert scale which assesses respondents overall evaluation of themselves, and the Robson self-concept questionnaire.19
Data analysis
In all analyses we weighted data (using the pweight command in
Stata 8.0 for Windows) to account for the oversampling of
African–Caribbean controls, using weights of 0.48 and 0.18 respectively
for African–Caribbean controls from London and Nottingham. We compared
the socio-demographic characteristics of those with psychosis and those
without who had completed the CANDID–2 questionnaire. We then conducted
a series of logistic regressions with case status (psychosis case or control)
as the dependent variable. To test our first hypothesis, that perceived
disadvantage mediates the association between ethnicity and case status, we
used the following steps: first, we determined whether ethnicity (the main
explanatory variable) was associated with perceived disadvantage; second, we
determined whether ethnicity was associated with psychosis (outcome) using
logistic regression adjusting for age, centre and gender, and reporting as
odds ratio; third, the odds ratio for relationship of perceived disadvantage
(mediator) with psychosis was determined; fourth, assuming that the first
three steps confirm a positive association, we added perceived disadvantage to
the logistic regression in step 2, to determine whether the size of the
association between ethnicity and psychosis was
reduced.20
We determined whether reports of perceived disadvantage correlated with any of the psychosis symptoms (in the case group), self-esteem and self-concept scores (in the whole sample), using Spearmans rho correlations, to explore whether reports of disadvantage might plausibly be related to specific symptoms. We repeated the logistic regression above with self-esteem and self-concept as the added independent variables, to determine whether they attenuated the relationship between ethnicity and case status. To test our second hypothesis that people with psychosis experienced more disadvantage after controlling for socio-economic variables, we entered all the socio-economic variables studied that approached significance (P<0.1) on univariate analysis in an overall model.
We investigated whether the categories (skin colour, culture and social class) of disadvantage were more likely to be experienced by people with psychosis compared with controls after controlling for ethnicity, age and gender. Finally, we qualitatively described and summarised the factors cited as contributing to social class, and additional reasons given for experiencing disadvantage in those with psychosis and those without.
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=–0.14, P=0.003) and
self-concept (
=–0.12, P=0.016) scores, but not with scores
for persecutory delusions (
=–0.055, P=0.46), delusions of
reference (
=–0.011, P=0.89), non-affective auditory
hallucinations (
=–0.021, P=0.78) or non-specific auditory
hallucinations (
=0.051, P=0.050). |
View this table: [in a new window] | Table 1 Comparison of socio-economic characteristics of the cases and control groups |
After controlling for age and gender, people from Black ethnic groups were over four times more likely to have psychosis than White people (Table 2). The association between Black ethnicity and case status was reduced by controlling for socio-economic factors (social class, educational level, religious adherence, employment) and for greater perception of disadvantage, confirming evidence of mediation, but increased by controlling for self-esteem and self-concept. In our final model (Table 3), being younger, unemployed and from a Black ethnic group, expressing adherence to some form of religion and perceiving more disadvantage were the significant factors predicting case status.
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View this table: [in a new window] | Table 2 Odds ratios for relationship between case status and Black ethnic group, adjusted for factors studied |
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View this table: [in a new window] | Table 3 Logistic regression of factors predicting case status (psychosis) |
Reasons for perceived disadvantage
People with psychosis were more likely than those in the control group to
report experiencing disadvantage due to skin colour (OR=1.2, 95% CI
1.1–1.4; P=0.009), but findings for cultural beliefs and
religion (OR =1.2, 95% CI 0.96–1.4; P=0.12) and social class
(OR=1.2, 95% CI 0.98–1.4; P=0.091) were not statistically
significant. However, once the higher perception of disadvantage scores by
Black people, who were more likely to be categorised as cases, were controlled
for, people with psychosis were no more likely to report perceiving
disadvantage due to cultural beliefs and religion or to social class, and they
were actually less likely to report disadvantage due to skin colour (OR= 0.82,
95% CI 0.68–0.98; P=0.027). The proportion of people who
reported being disadvantaged due to culture or religion at least part of the
time (score 3 or above) was greater in Black people (26.1%) than in White
people (6.0%); this was also true for reports of disadvantage due to skin
colour (55.0% v. 4.8%) and social class (27.1% v.
12.1%).
Qualitative analyses
Culture and religion
Several respondents mentioned specific situations in which they felt they
were disadvantaged because of their culture, most frequently in seeking
employment. One person with psychosis originally from Yugoslavia described
snide remarks from colleagues about taking jobs at the expense of
British people. Several reported tensions emanating from a clash of
their own and British culture. One Black person with psychosis commented,
I was supposed to follow my culture but was prevented from doing
this. Others who made additional comments attributed cultural
disadvantage to their physical appearance (e.g. dreadlocks, mode of dress), or
language (e.g. accent, disapproval of communication in their own language in
public). Some described negative assumptions made by others as a result of
their culture. One Black person recruited as a control commented, I
didnt feel people of my colour could achieve and this seemed to be
confirmed by my teachers. A Black person with psychosis commented,
[The discrimination] boils down to what happens to us and our history.
Whites will never fully respect us. Another stated that, The
people in power dont like Black culture. Three people (all
categorised as cases: one from a White group and two from Black groups)
specifically commented about racism.
Skin colour
One person with psychosis commented, Youre seen as just a
Black person; another that Black men were seen as
aggressive. Twelve White people from the control group (compared with
one from the cases group) reported feeling that people from ethnic minorities
were given preferential treatment in British society.
Social class
The majority of comments concerned lack of opportunities in education and
employment due to being from a lower social class. When asked what determined
social class, the most frequently endorsed responses were wealth or income
(n=233; 48.3%), family background (n=215; 48.2%), education
(n=168; 37.7%), occupation (n=101; 21.0%), address
(n=58; 12.0%) and the persons own behaviour and attitudes
(n=40; 8.3%). There was no significant difference in the proportion
of people with and without psychosis citing these factors.
Other reasons for disadvantage
Finally, we investigated other reasons given for perceiving disadvantage in
those with psychosis (n=67) and those without (n=64). The
most frequent answers were gender (8 cases, 9 controls); health or disability
(physical or unspecified; 5 cases, 9 controls); racism, nationality or asylum
status (6 cases, 9 controls); lack of education or support at school (10
cases, 3 controls); family background, problems or lack of support (8 cases, 3
controls); own lack of confidence, attitude or behaviour (7 cases, 2
controls); financial factors (2 cases, 7 controls); social class, profession
or social exclusion (3 cases, 5 controls); age (2 cases, 6 controls); the
negative attitudes of others (4 cases, 4 controls); appearance or height (5
cases, 1 control); manner of speech, accent or use of language (1 case, 2
controls) and bad luck (3 cases, 0 controls). Only one respondent (with
psychosis) specifically mentioned mental health as a reason for
discrimination.
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This research touches on two key theoretical issues in psychosis. The first is how social contexts shape the content of psychotic symptoms.21 The second is the central role of appraisal in cognitive models of psychosis.22 One might predict that perceiving disadvantage would give rise to paranoid thoughts. It is clear that incidents of discrimination occur, and in any given society there will be groups who experience them more often than others, and ethnic groups for whom the experience is qualitatively different. Where individuals appraise such incidents as personally directed, they may regard them as persecutory, and persecutory patterns of thought may be initiated. If so, this would represent a direct cognitive pathway into paranoid interpretations. The converse, that a paranoid view of the world may increase the perception of experiences as disadvantageous, would also seem a reasonable assumption. It is therefore surprising that we found no correlation between perceived disadvantage and persecutory delusions or other measures of psychotic symptoms in our study. This suggests that the participants recognition of disadvantage was not greatly distorted by specific psychotic patterns of thinking.
Black people with psychosis reported particularly high rates of disadvantage, but they were no more likely than other Black people to attribute this to their culture, religion, social class or skin colour, and they were less likely than other Black people to include the possibility of racism in their comments. Their greater perception of disadvantage must therefore have other attributions. When asked to comment upon 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: only one participant mentioned mental health. There is no reason to doubt the reports of people with psychosis that they received less support at school or home. Black pupils in England are more likely to be expelled than those from White UK ethnic groups,23 so this could potentially contribute to some of the excess of psychosis in Black groups. Many of the reasons given by people with psychosis for perceived discrimination are suggestive of negative self-beliefs. Such beliefs may have led people with psychosis to blame themselves for a disadvantage that might have been more accurately attributed to race, culture, class or mental illness. It has been suggested previously that negative schematic beliefs about the self might have a role in the origin and maintenance of psychosis.24,25 It is possible that correctly identifying hostility as due to anothers prejudice rather than to internal factors is protective, and that those unable to do so are more vulnerable to developing psychosis.
Although our findings do not support a direct link between the perception of disadvantage and the specific emergence of persecutory delusions, perceptions of disadvantage could act synergistically with other affective mechanisms to evoke psychotic symptoms. Modern cognitive models claim that emotional processes act singly or in combination with cognitive biases in vulnerable individuals to increase the risk of positive psychotic symptom formation through the resulting appraisal patterns.26–29
Low self-esteem and poor self-concept are indicators of emotional biases that might act in such a way. The Rosenberg measure of self-esteem, sufficiently closely associated with depressed mood to serve as a proxy for affect,30 was clearly associated with psychosis in our study. Those perceiving greater disadvantage had significantly poorer self-esteem and self-concepts, although the size of the association was small. Such associations have been reported before.31 It has been suggested that extreme negative evaluations of the self and others mediate the link between emotional processes and positive symptoms of psychosis.24,25 However, this could not explain the increased rates of perception of disadvantage among Black participants because, in line with previous findings,32 ÆSOP participants from non-White ethnic groups reported higher self-esteem and self-concept scores.33 Controlling for these factors thus increased the odds ratio for the relationship between Black ethnicity and psychosis.
Our findings thus lead us to conclude that the greater disadvantages perceived by Black participants were due neither to psychotic symptoms nor to negative self-perceptions. A logical assumption would be that they were probably due to actual discriminatory experiences. Such a hypothesis should be considered with caution, as we measured perception of disadvantage rather than actual experiences. It is, however, supported by previous studies of associations of psychosis with discrimination and racist abuse.3,4 We agree with previous authors5 that a longitudinal study–for example of people at high risk who have yet to develop psychosis–is now needed to determine whether disadvantage, perceived or actual, predicts the emergence of psychosis. Qualitative research to explore notions of perceived disadvantage across ethnic groups would also be an interesting direction for future work.
Limitations of the study
Direction of causality cannot be determined from this cross-sectional
study. We categorised ethnicity and religion into broad groups to ensure we
had adequate power to test our hypotheses, but there might well have been
diversity in the experiences of disadvantage within groups, for example the
experiences of White Irish people probably differed from those of White
British people. Those not interviewed because they did not speak English might
have experienced particularly high levels of disadvantage. The response rate
for the cases group was fairly low and this might have led to either over-or
underestimation of mediation. We could not include all potential confounders;
for example, we did not measure recent life events or early life experiences,
which might have contributed to the participants perceptions of
disadvantage. The questions relating to perceptions of disadvantage were
single-item Likert scales which had not been individually validated. We have
hypothesised that the participants perceptions of disadvantage were
based on actual discriminatory experiences, but these were not measured
directly.
Implications of the study
Perceived disadvantage partly mediated the relationship between psychosis
and ethnicity, lending support to the hypothesis that disadvantage, perceived
or actual, might contribute to the excess of psychosis observed in Black
ethnic groups in the UK. If those who experience more disadvantage are indeed
more prone to psychosis, it would have important consequences both for primary
prevention and for treatment. However, people with psychosis are more likely
to perceive that they are disadvantaged in society, even after taking into
account ethnicity, social class and other socio-economic factors. Few people
with psychosis attributed the disadvantage they felt to mental illness or
racism, and they were more likely to attribute it to their own appearance or
behaviour, or to lack of support at school or home. A longitudinal study is
now needed to determine the direction of causality.
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