Differential relationship between neurological and cognitive dysfunction in first episode psychosis patients and in healthy individuals.

The minor neurological and cognitive deficits consistently reported in psychoses may reflect the same underlying brain dysfunction. Still, even in healthy individuals minor neurological abnormalities are associated with worse cognitive function. Therefore, establishing which neurological and cognitive deficits are specific to psychosis is essential to inform the pathophysiology of this disorder. We evaluated a large epidemiological sample of patients with first episode psychosis (n=242) and a population-based sample of healthy individuals (n=155), as part of the AESOP study. We examined neurological soft signs using the Neurological Evaluation Scale (Buchanan and Heinrichs, 1989), and generalized and specific cognitive deficits (memory; verbal abilities; attention, concentration and mental speed; executive functions and working memory; language; visual constructual/perceptual abilities). In patients, more neurological signs across all subscales were associated with worse general cognitive function, while in controls this was only present for sensory integration and sequencing signs. Furthermore, in patients, but not in healthy individuals, more sensory integrative signs were associated with deficits in specific cognitive domains, such as memory, verbal abilities, language, visual/perceptual, executive function (p ranging <0.001-0.002); sequencing signs with language, executive function, and attention (p<0.001-0.004); and motor signs with poorer verbal abilities (p=0.001). These findings indicate the presence of specific associations between neurological and cognitive deficits in psychosis that are distinct from those of healthy individuals.

Linear and non-linear associations of symptom dimensions and cognitive function in first-onset psychosis.

BACKGROUND: Associations between symptom dimensions and cognition have been mainly studied in non-affective psychosis. The present study investigated whether previously reported associations between cognition and four symptom dimensions (reality distortion, negative symptoms, disorganisation and depression) in non-affective psychosis generalise to a wider spectrum of psychoses. It also extended the research focus to mania, a less studied symptom dimension. METHODS: Linear and non-linear (quadratic, curvilinear or inverted-U-shaped) associations between cognition and the above five symptom dimensions were examined in a population-based cohort of 166 patients with first-onset psychosis using regression analyses. RESULTS: Negative symptoms showed statistically significant linear associations with IQ and processing speed, and a significant curvilinear association with verbal memory/learning. Significant quadratic associations emerged between mania and processing speed and mania and executive function. The contributions of mania and negative symptoms to processing speed were independent of each other. The findings did not differ between affective and non-affective psychoses, and survived correction for multiple testing. CONCLUSIONS: Mania and negative symptoms are associated with distinct patterns of cerebral dysfunction in first-onset psychosis. A novel finding is that mania relates to cognitive performance by a complex response function (inverted-U-shaped relationship). The associations of negative symptoms with cognition include both linear and quadratic elements, suggesting that this dimension is not a unitary concept. These findings cut across affective and non-affective psychoses, suggesting that different diagnostic entities within the psychosis spectrum lie on a neurobiological continuum.

Satisfaction with inpatient treatment for first-episode psychosis among different ethnic groups: a report from the UK AeSOP study.

BACKGROUND: There is concern about the level of satisfaction with mental healthcare among minority ethnic patients in the UK, particularly as black patients have more compulsory admissions to hospital. AIMS: To determine and compare levels of satisfaction with mental healthcare between patients from different ethnic groups in a three-centre study of first-onset psychosis. METHOD: Data were collected from 216 patients with first-episode psychosis and 101 caregivers from South London, Nottingham and Bristol, using the Acute Services Study Questionnaire (Patient and Relative Version) and measures of sociodemographic variables and insight. RESULTS: No differences were found between ethnic groups in most domains of satisfaction tested individually, including items relating to treatment by ward staff and number of domains rated as satisfactory. However, logistic regression modelling (adjusting for age, gender, social class, diagnostic category and compulsion) showed that black Caribbean patients did not believe that they were receiving the right treatment and were less satisfied with medication than white patients. Black African patients were less satisfied with non-pharmacological treatments than white patients. These findings were not explained by lack of insight or compulsory treatment. CONCLUSIONS: The study found that black patients were less satisfied with specific aspects of treatment, particularly medication, but were equally satisfied with nursing and social care. Understanding the reasons behind this may improve the acceptability of psychiatric care to black minority ethnic groups.

Association between locus of control in childhood and psychotic symptoms in early adolescence: results from a large birth cohort.

INTRODUCTION. Specific attributional styles have been demonstrated in individuals with psychotic disorders and are implicated in the development of psychotic symptoms. We aimed to examine the association between locus of control (LOC) assessed in childhood and psychotic symptoms reported in early adolescence. METHODS. We used a prospective longitudinal design using data from a large birth cohort (the Avon Longitudinal Study of Parents and Children, ALPSAC). 6455 subjects completed a semistructured clinical interview assessing 12 individual psychotic symptoms at a mean age of 12.9 years. A measure of LOC was previously collected in the cohort at the age of 8. RESULTS. Children who reported an externalised LOC at age 8 were at increased risk of reporting both broadly defined (OR 1.77, 95% CI 1.49 to 2.08) and narrowly defined (OR 2.06, 95% CI 1.58 to 2.67) psychotic symptoms at age 13 years. These associations were only slightly attenuated after adjustment for potential confounders. The associations were similar for broadly defined specific paranoid symptoms but weaker for narrowly defined specific paranoid symptoms. CONCLUSIONS. An externalised LOC appears to be associated with later reporting of psychotic symptoms in early adolescence. Further investigation of the role of attributional styles, such as LOC, in increasing the risk for psychotic disorders, is warranted.

Childhood facial emotion recognition and psychosis-like symptoms in a nonclinical population at 12 years of age: results from the ALSPAC birth cohort.

INTRODUCTION: Nonclinical psychotic symptoms (for example, low intensity or low frequency psychotic symptoms such as ideas of reference or single word auditory hallucinations) are common in adolescents and may be associated with an increased risk of developing a psychotic disorder in adulthood. Those at high risk of developing a psychotic disorder appear to perform poorly on facial emotion recognition tasks but the relationship between facial emotion recognition and nonclinical "psychosis like symptoms" (PLIKS) in children is unclear. We aimed to examine the association between childhood facial emotion recognition and PLIKS in adolescents. METHODS: Longitudinal study using a large birth cohort. 6455 subjects completed a semistructured clinical assessment for psychotic symptoms (the PLIKSi) at the mean age of 12.9 (SD=0.23). Facial emotion recognition (using the DANVA) was previously assessed at the age of 8 in the cohort. RESULTS: There was no increase in odds of reporting any PLIKS either in relation to the total score on the measure of facial emotion recognition or for the individual emotion scores of fear, sadness, anger, and happiness. Similar results were also found when examining more intense and/or more frequently experienced psychotic symptoms. CONCLUSIONS: Deficits in facial emotion recognition in 8-year-olds do not appear to predict later reporting of nonclinical psychotic symptoms in early adolescence. The results do not support the proposal that recognition of emotion is a trait phenomenon in those individuals at increased risk for psychosis. However, further research is warranted in older children/adolescents when more subtle emotion recognition deficits can be investigated.

The association between substance misuse and first-episode psychosis in a defined UK geographical area during the 1990s.

OBJECTIVE: The aim of this study was to examine the prevalence of all substance use disorders (SUD) and cannabis-specific SUDs reported in two first-episode epidemiological studies, conducted in the same catchment area, 5 years apart. METHODS: The prevalence of schizophrenia in Nottingham and Aetiology and Ethnicity of Schizophrenia and Other Psychoses studies included all people with a first-episode of psychosis between 1992 and 1994 and 1997 and 1999, respectively. Those individuals with a comorbid diagnosis of a SUD (ICD-10 harmful use or dependence) were identified. RESULTS: An upward (but not statistically significant) trend in all SUDs was found for the first-episode study population as a whole, between the two cohorts (11.9-18.2%). When analysed by age, a significant increase in cannabis-specific SUDs was observed for all first-episode cases aged 16-29 between cohorts (3.2-10.6%). When analysed by age and gender, a significant increase in all SUDs was apparent for female first-episode patients aged 16-29 between cohorts (6.1-24.2%), this same increase was not seen in male patients. CONCLUSIONS: Illegal drug misuse is common in patients with a first-episode of psychosis. However, most concerning is that when both age and gender are considered, females with a first-episode of psychosis aged 16-29 show a highly significant rise in the prevalence of all SUDs over the 1990s. More recent drug use data from England and Wales shows that the prevalence of drug use in the 21st century is declining; further epidemiological studies are required to determine whether this is also the case in young female first-episode psychosis populations.

Examining the association between maternal analgesic use during pregnancy and risk of psychotic symptoms during adolescence.

BACKGROUND: Children and adolescents who report psychotic symptoms in non-clinical samples are at an increased risk of developing schizophrenia. Study of such 'high risk' groups may increase our understanding of early risk factors for psychotic illnesses. Maternal infection during pregnancy is associated with an increased risk of schizophrenia in the offspring, and it has been hypothesised that exposure to maternal intake of analgesics during pregnancy, taken to alleviate the symptoms of viral infections, may partly explain this association. The aim of this study was to examine the relationship between maternal use of aspirin and other analgesics during pregnancy and the occurrence of psychotic symptoms in the offspring. METHODS: This was a longitudinal study of 6437 children belonging to the Avon Longitudinal Study of Parents and Children (ALSPAC) cohort who participated in the psychosis-like-symptoms semi-structured interview (PLIKSi) at 12years of age. Data on in-utero exposure to analgesics were obtained from self-report questionnaires completed by the mothers during pregnancy. RESULTS: Increasing frequency of aspirin use during pregnancy was associated with an increased risk of psychotic experiences (adjusted OR 1.44, 95% CI 1.08-1.92). Risk was highest in those whose mothers used aspirin most days or daily (adjusted OR 2.79, 95% CI 1.27-6.07). Paracetamol and other analgesic use during pregnancy were not associated with the risk of offspring psychotic symptoms. CONCLUSIONS: Medications such as aspirin that interfere with the prostaglandin pathway, taken during pregnancy, may influence the risk of schizophrenia in the offspring. Other epidemiological studies are needed to examine this association further.

Translating the epidemiology of psychosis into public mental health: evidence, challenges and future prospects.

Genetic and environmental factors are associated with psychosis risk, but the latter present more tangible markers for prevention. We conducted a theoretical exercise to estimate the proportion of psychotic illnesses that could be prevented if we could identify and remove all factors that lead to increased incidence associated with ethnic minority status and urbanicity. Measures of impact by population density and ethnicity were estimated from incidence rate ratios [IRR] obtained from two methodologically-similar first episode psychosis studies in four UK centres. Multilevel Poisson regression was used to estimate IRR, controlling for confounders. Population attributable risk fractions [PAR] were estimated for our study population and the population of England. We considered three outcomes; all clinically relevant ICD-10 psychotic illnesses [F10-39], non-affective psychoses [F20-29] and affective psychoses [F30-39]. One thousand and twenty-nine subjects, aged 18-64, were identified over 2.4 million person-years. Up to 22% of all psychoses in England (46.9% within our study areas) could be prevented if exposures associated with increased incidence in ethnic minority populations could be removed; this is equivalent to 66.9% within ethnic minority groups themselves. For non-affective psychoses only, PAR for population density was large and significant (27.5%); joint PAR with ethnicity was 61.7%. Effect sizes for common socio-environmental risk indicators for psychosis are large; inequalities were marked. This analysis demonstrates potential importance in another light: we need to move beyond current epidemiological approaches to elucidate exact socio-environmental factors that underpin urbanicity and ethnic minority status as markers of increased risk by incorporating gene-environment interactions that adopt a multi disciplinary perspective.

Effectiveness of a cognitive behavioural workbook for changing beliefs about antipsychotic polypharmacy: analysis from a cluster randomized controlled trial.

RATIONALE, AIMS AND OBJECTIVES: Educational workbooks have been used in psychiatry to influence patient but not clinician behaviour. Targeted education interventions to change prescribing practice in other areas of medicine have only looked at changes in prescribing and not attitudes or beliefs related to the prescribing. We aimed to examine whether clinicians' beliefs about a common prescribing issue in psychiatry (antipsychotic polypharmacy prescription) changed alongside behaviour as a result of a complex intervention. METHOD: Medical and nursing staff were recruited from 19 general adult psychiatry units in the south-west of the UK as part of a cluster randomized controlled trial. A questionnaire was used to assess beliefs on the prescribing of antipsychotic polypharmacy as a secondary outcome before and after completion of a cognitive behavioural 'self-help' style workbook (one part of a complex intervention). A factor analysis suggested three dimensions of the questionnaire that corresponded to predetermined themes. The data were analysed using a random-effects regression model (adjusting for clustering) controlling for possible confounders. RESULTS: There was a significant change in beliefs on both of the factors: antipsychotic polypharmacy (coefficient = -0.89, P < 0.01) and rapid tranquilization (coefficient = -0.68, P = 0.01) specifically targeted by the workbook. There was a modest but statistically significant change in antipsychotic polypharmacy prescribing (odds ratio 0.43, 95% confidence intervals 0.21-0.90). CONCLUSIONS: The workbook appeared to change staff beliefs about antipsychotic polypharmacy, but achieving substantial changes in clinician behaviour may require further exploration of other factors important in complex prescribing issues.

Maternal tobacco, cannabis and alcohol use during pregnancy and risk of adolescent psychotic symptoms in offspring.

BACKGROUND: Adverse effects of maternal substance use during pregnancy on fetal development may increase risk of psychopathology. AIMS: To examine whether maternal use of tobacco, cannabis or alcohol during pregnancy increases risk of offspring psychotic symptoms. METHOD: A longitudinal study of 6356 adolescents, age 12, who completed a semi-structured interview for psychotic symptoms in the Avon Longitudinal Study of Parents and Children (ALSPAC) birth cohort. RESULTS: Frequency of maternal tobacco use during pregnancy was associated with increased risk of suspected or definite psychotic symptoms (adjusted odds ratio 1.20, 95% CI 1.05-1.37, P = 0.007). Maternal alcohol use showed a non-linear association with psychotic symptoms, with this effect almost exclusively in the offspring of women drinking >21 units weekly. Maternal cannabis use was not associated with psychotic symptoms. Results for paternal smoking during pregnancy and maternal smoking post-pregnancy lend some support for a causal effect of tobacco exposure in utero on development of psychotic experiences. CONCLUSIONS: These findings indicate that risk factors for development of non-clinical psychotic experiences may operate during early development. Future studies of how in utero exposure to tobacco affects cerebral development and function may lead to increased understanding of the pathogenesis of psychotic phenomena.

Neuropsychological functioning in first-episode schizophrenia.

BACKGROUND: Identifying neurocognitive subtypes in schizophrenia may help establish neurobiologically meaningful subtypes of the disorder, but is frequently confounded by differences in intellectual function between individuals with schizophrenia and controls. AIMS: To examine neuropsychological performance in individuals with epidemiologically based, first-onset schizophrenia and intellectually matched controls. METHOD: Using standard IQ and reading tests, we examined the proportions of 101 people with epidemiologically derived, first-onset schizophrenia/schizoaffective disorder and 317 community controls, falling into three a priori defined intellectual categories: 'stable good', 'deteriorated poor' and 'stable poor'. Neuropsychological function was compared between intellectually matched participants with schizophrenia and control subgroups. RESULTS: Multiple deficits in executive function, processing speed and verbal memory, but not visual/spatial perception/memory, were detected in all participant groups with schizophrenia compared with controls. The average effect size across the affected domains ranged from small to medium to large in the stable good, deteriorated poor and stable poor subgroups of participants with schizophrenia, respectively. CONCLUSIONS: Compared with intellectually matched controls, people with epidemiologically derived, first-onset schizophrenia/schizoaffective disorder show multiple deficits in executive function, processing speed and verbal memory.

Selective deficits in semantic verbal fluency in patients with a first affective episode with psychotic symptoms and a positive history of mania.

OBJECTIVES: Neurocognitive dysfunction is likely to represent a trait characteristic of bipolar disorder, but the extent to which it comprises 'core' deficits as opposed to those secondary to longstanding illness or intellectual decline is unclear. We investigated neuropsychological performance in an epidemiologically derived sample of patients with a first affective episode with psychotic symptoms and a positive history of mania, compared to community controls. METHODS: Using a nested case-control, population-based study, measures of episodic and working memory, executive function, processing speed, and visual-spatial perception were compared between 35 patients with a first affective episode with psychotic symptoms and a positive history of mania, and 274 community controls, as well as a subgroup of 105 controls matched on current IQ ('good' versus 'poor') and IQ trajectory ('stable', 'declined', or 'improved') with the patients (three controls per case). RESULTS: Compared to the extended control sample, probands showed a suggestive deficit in short-term verbal recall, and a significant deficit in semantic fluency. Only the latter was detectable in the comparison with the IQ-matched controls. All other neurocognitive domains showed intact performance or nonsignificant deficits of small effect sizes compared to both control groups. Semantic fluency showed no association with symptoms or duration of untreated illness. CONCLUSIONS: Patients with a first affective episode with psychotic symptoms and a positive history of mania show an isolated, selective deficit in semantic verbal fluency, against a background of generally preserved neurocognitive function. This pattern seems to contrast with the more widespread neuropsychological dysfunction seen in schizophrenia.

Prospective study of peer victimization in childhood and psychotic symptoms in a nonclinical population at age 12 years.

CONTEXT: Psychotic symptoms are commonly experienced in nonclinical populations of adolescents and adults and have been shown to be predictive of later schizophreniform disorders. Associations between adverse experiences in childhood and psychotic symptoms in adulthood have been demonstrated. OBJECTIVE: To examine whether peer victimization is associated with psychotic symptoms in a population-based sample of 12-year-olds. DESIGN: Prospective cohort study. SETTING: Assessment clinic for 12-year-old members of the Avon Longitudinal Study of Parents and Children birth cohort in Bristol, England, where parents had participated since pregnancy and their children completed a range of physical and psychological annual assessments since age 7 years. PARTICIPANTS: A total of 6437 respondents with complete interviews (mean age, 12.9 years). MAIN OUTCOME MEASURE: The Psychosis-like Symptoms Interview developed for the study using stem questions, glossary definitions, and rating rules, adapted from the National Institute of Mental Health Diagnostic Interview Schedule for Children-IV and the Schedules for Clinical Assessment in Neuropsychiatry. The interview, carried out by trained psychology graduates, investigated respondents' experience of psychotic symptoms (hallucinations, delusions, and thought disorders) over the previous 6 months. RESULTS: The risk of psychotic symptoms was increased about 2-fold (odds ratio = 1.94; 95% confidence interval, 1.54-2.44) among victims of bullying at ages 8 and/or 10 years, independent of other prior psychopathology, family adversity, or child's IQ. Similar results were found using mother and teacher reports of victimization. Associations were stronger (up to odds ratio = 4.60; 95% confidence interval, 3.24-6.50) when victimization was chronic or severe (ie, experience of relational as well as overt victimization reported). CONCLUSIONS: Peer victimization in childhood, especially if it is chronic or severe, is associated with psychotic symptoms in early adolescence. These results lend further support to the relevance of psychosocial factors in the etiology of psychotic symptoms in nonclinical populations, which may increase the risk of adult-onset psychotic disorders.

Neurological abnormalities and cognitive ability in first-episode psychosis.

BACKGROUND: It remains unclear if the excess of neurological soft signs, or of certain types of neurological soft signs, is common to all psychoses, and whether this excess is simply an epiphenomenon of the lower general cognitive ability present in psychosis. AIMS: To investigate whether an excess of neurological soft signs is independent of diagnosis (schizophrenia v. affective psychosis) and cognitive ability (IQ). METHOD: Evaluation of types of neurological soft signs in a prospective cohort of all individuals presenting with psychoses over 2 years (n=310), and in a control group from the general population (n=239). RESULTS: Primary (P<0.001), motor coordination (P<0.001), and motor sequencing (P<0.001) sign scores were significantly higher in people with any psychosis than in the control group. However, only primary and motor coordination scores remained higher when individuals with psychosis and controls were matched for premorbid and current IQ. CONCLUSIONS: Higher rates of primary and motor coordination signs are not associated with lower cognitive ability, and are specific to the presence of psychosis.

IQ and non-clinical psychotic symptoms in 12-year-olds: results from the ALSPAC birth cohort.

BACKGROUND: Non-clinical psychotic symptoms appear common in children, but it is possible that a proportion of reported symptoms result from misinterpretation. There is a well-established association between pre-morbid low IQ score and schizophrenia. Psychosis-like symptoms in children may also be a risk factor for psychotic disorder but their relationship with IQ is unclear. AIMS: To investigate the prevalence, nature and frequency of psychosis-like symptoms in 12-year-old children and study their relationship with IQ. METHOD: Longitudinal study using the Avon Longitudinal Study of Parents and Children (ALSPAC) birth cohort. A total of 6455 children completed screening questions for 12 psychotic symptoms followed by a semi-structured clinical assessment. IQ was assessed at 8 years of age using the Wechsler Intelligence Scale for Children (3rd UK edition). RESULTS: The 6-month period prevalence for one or more symptoms was 13.7% (95% CI 12.8-14.5). After adjustment for confounding variables, there was a non-linear association between IQ score and psychosis-like symptoms, such that only those with below average IQ score had an increased risk of reporting such symptoms. CONCLUSIONS: Non-clinical psychotic symptoms occur in a significant proportion of 12-year-olds. Symptoms are associated with low IQ and also less strongly with a high IQ score. The pattern of association with IQ differs from that observed in schizophrenia.

Neurological abnormalities and cognitive ability in first-episode psychosis.

BACKGROUND: It remains unclear if the excess of neurological soft signs, or of certain types of neurological soft signs, is common to all psychoses, and whether this excess is simply an epiphenomenon of the lower general cognitive ability present in psychosis. AIMS: To investigate whether an excess of neurological soft signs is independent of diagnosis (schizophrenia v. affective psychosis) and cognitive ability (IQ). METHOD: Evaluation of types of neurological soft signs in a prospective cohort of all individuals presenting with psychoses over 2 years (n=310), and in a control group from the general population (n=239). RESULTS: Primary (P<0.001), motor coordination (P<0.001), and motor sequencing (P<0.001) sign scores were significantly higher in people with any psychosis than in the control group. However, only primary and motor coordination scores remained higher when individuals with psychosis and controls were matched for premorbid and current IQ. CONCLUSIONS: Higher rates of primary and motor coordination signs are not associated with lower cognitive ability, and are specific to the presence of psychosis.

Investigating if psychosis-like symptoms (PLIKS) are associated with family history of schizophrenia or paternal age in the ALSPAC birth cohort.

Psychosis-like symptoms (PLIKS) occur in about 15% of the population, but it is unclear to what extent PLIKS share aetiological mechanisms in common with those for schizophrenia. We examined whether the presence of PLIKS was associated with a family history of schizophrenia (FH-SCZ), or with advancing paternal age, using data from 6356 children in the ALSPAC birth cohort who participated in a semi-structured PLIKS interview at 12 years of age. We found no evidence of association between FH-SCZ and suspected or definite PLIKS (adjusted OR=0.94, 95%CI 0.44, 2.00; p=0.880). There was weak evidence that advancing paternal age was associated with increased PLIKS (adjusted OR per 10-year age increase=1.23, 95%CI 0.99, 1.55; p=0.058). Although not a priori hypotheses, family history of depression (adjusted OR=1.28, 95%CI 1.04, 1.57; p=0.018), and younger maternal age (adjusted OR per 10-year age increase=0.62, 95% CI 0.47, 0.82; p<0.001) both showed stronger evidence of association with suspected or definite PLIKS. Overall our findings provide little evidence that these established risk factors for schizophrenia show a similar relationship with PLIKS, suggesting that the presence of PLIKS is unlikely to be a strong marker of early expression of the pathology underlying schizophrenia. Whether future studies of PLIKS will increase our understanding of mechanisms underlying the development of schizophrenia, or prove useful in prediction of this disorder, remains to be seen.

Perceptions of disadvantage, ethnicity and psychosis.

BACKGROUND: 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 (AESOP)). 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.

Perceptions of disadvantage, ethnicity and psychosis.

BACKGROUND: 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 (AESOP)). A total of 482 participants answered questions about perceived disadvantage. RESULTS: Black ethnic groups had a higher incidence of psychosis (OR= 4.7, 95 per cent 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 per cent 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.

Risk of schizophrenia and other non-affective psychosis among individuals exposed to head injury: case control study.

Studies of the risk of schizophrenia and related non-affective psychoses among individuals exposed to head injury have reported conflicting findings. The diagnostic specificity of reported associations remains unclear and the effects of sex, genetic vulnerability and timing of exposures are also uncertain. The authors used a comprehensive range of data derived from the linkage of several Swedish registers to investigate associations of head injury with schizophrenia and other non-affective psychoses. We carried out a nested case control study drawn from a cohort of 785,051 men and women born between 1973 and 1980. After head injury exposure, there was a small increase in the risk (OR 1.37 (CI 1.14-1.66)) of non-schizophrenic, non-affective psychoses but not schizophrenic disorder (OR 1.10 CI 0.82 to 1.47). There was no critical period effect for exposures in early childhood, the association with non-affective psychosis being observed only in those exposed to head injury after age 10. There was no evidence that associations differed in males and females or in those with, and those without, a family history of psychosis. We conclude that it is unlikely that head injury causes schizophrenia. There is a small but significant risk of non-schizophrenic psychotic disorders but this is not associated with early age of injury or family history of psychosis. Further research is needed to clarify the potential roles of social and biological intermediary factors.