J. van Os

Incidence of schizophrenia in ethnic minorities in London: ecological study into interactions with environment

Abstract Objective: To determine whether the incidence of schizophrenia among people from non-white ethnic minorities is greater in neighbourhoods where they constitute a smaller proportion of the total population. Design: Ecological design including retrospective study of case records to calculate the incidence of schizophrenia in the ethnic minority population across electoral wards and multi-level analysis to examine interaction between individuals and environment. Setting: 15 electoral wards in Camberwell, South London. Participants: All people aged 16 years and over who had contact with psychiatric services during 1988-97. Main outcome measure: Incidence rates of schizophrenia according to Research Diagnostic Criteria. Results: The incidence of schizophrenia in non-white ethnic minorities increased significantly as the proportion of such minorities in the local population fell. The incidence rate ratio varied in a dose-response fashion from 2.38 (95% confidence interval 1.49 to 3.79) in the third of wards where non-white ethnic minorities formed the largest proportion (28-57%) of the local population to 4.4 (2.49 to 7.75) in the third of wards where they formed the smallest proportion (8-22%). Conclusion: The incidence of schizophrenia in non-white ethnic minorities in London is greater when they comprise a smaller proportion of the local population. What is already known on this topic An increased incidence of schizophrenia has been reported in several ethnic minorities in the United Kingdom Biological risk factors do not seem to explain this Reports from the United States have shown an association between the proportion of an ethnic minority living in an area and their admission rates for mental illness in general What this study adds The lower the proportion of non-white ethnic minorities in a local area the higher the incidence of schizophrenia in those minorities

Emotional reactivity to daily life stress in psychosis and affective disorder: an experience sampling study.

Objective:  To investigate the emotional reactivity to small disturbances in daily life in patients with non‐affective psychosis (NAP), bipolar disorder (BD) and major depression [major depressive disorder (MDD)].

Psychopathological syndromes in the functional psychoses : associations with course and outcome

The aim of this study was to identify underlying dimensions of psychopathology in a cohort of patients with functional psychosis of recent onset, and to examine their prognostic value. Factor analysis of the psychopathological features of 166 consecutively admitted patients with functional psychosis of recent onset revealed seven psychopathological dimensions, which explained 63% of the variance. Five of these seven syndromes bore differential associations with subsequent treatment and illness course, independent of: (i) associations with DSM-III-R diagnosis; (ii) associations with other prognostic factors; and (iii) associations with the baseline values of outcome variables. The most striking associations were shown for an early and insidious onset syndrome with affective flattening, which predicted a more disabled course of illness on three of four outcome dimensions, and which was more common in males and unmarried individuals. A second syndrome, characterized by bizarre behaviour, inappropriate affect, catatonia, and poor rapport showed similar, slightly less striking, associations with illness course, as well as with poor pre-morbid social functioning. A third syndrome, characterized by positive psychotic symptoms was to a lesser degree associated with poorer outcome, whereas a fourth syndrome distinguished by manic symptomatology predicted a more benign illness course. A fifth syndrome identified by lack of insight predicted more time in hospital and admission under a section of the Mental Health Act during the follow-up period. A further finding was that dimensional representations of psychopathological features were considerably more useful than categorical representations (DSM-III-R and ICD-10) as predictors of illness course and treatment decisions.

Psychotic illness in ethnic minorities: clarification from the 1991 census

Age and sex-adjusted first admission rates for operationally-defined schizophrenia and other non-affective psychosis in different ethnic groups were calculated over the period 1988-1992 in a defined catchment area in South London. Standardized rates for schizophrenia, corrected for age- and gender-related under-reporting in the 1991 census and a 20% underestimate of the size of the ethnic minority populations in the area, were not only higher in the Afro-Caribbean group (SMR: 3.1; 95% C1:2.0-4.7), but also in the African group (SMR: 4.2; 95% C1: 2.8-6.2). It was further found that higher rates were not specific to schizophrenia. These findings suggest that some common factor associated with ethnic minority membership is important in producing an excess of psychotic illness.

Urbanization and risk for schizophrenia: does the effect operate before or around the time of illness onset?

Background. Higher level of urbanicity of place of birth and of place of residence at the time of illness onset has been shown to increase the risk for adult schizophrenia. However, because urban birth and urban residence are strongly correlated, no conclusions can be drawn about the timing of the risk-increasing effect. The current study discriminated between any effect of urbanization before and around the time of illness onset. Methods. All individuals born between 1972 and 1978 were followed up through the Dutch National Psychiatric Case Register for first admission for schizophrenia until 1995 (maximum age 23 years). Exposure status was defined by a combination of place of birth and place of residence at the time of illness onset in the three most densely populated provinces of the Netherlands (the ‘Randstad’, exposed) or in all other areas (the ‘non-Randstad’, non-exposed). The risk for schizophrenia was examined in four different exposure groups: non-exposed born and non-exposed resident (NbNr, reference category), non-exposed born and exposed resident (NbEr), exposed born and non-exposed resident (EbNr) and exposed born and exposed resident (EbEr). Results. The greatest risk for schizophrenia was found in the EbNR group, without evidence for any additive effect of urban residence (rate ratio (RR) for narrow schizophrenia in EbNr group, 2·05 (95% CI 1·18–3·57); in EbEr group, 1·96 (95% CI, 1·55–2·46)). Individuals who were not exposed at birth, but became so later in life, were not at increased risk of developing schizophrenia (RR for narrow schizophrenia in NbEr group, 0·79 (0·46–1·36)). Conclusion. The results suggest that environmental factors associated with urbanization increase the risk for schizophrenia before rather than around the time of illness onset.

Antipsychotic-induced tardive dyskinesia and polymorphic variations in COMT, DRD2, CYP1A2 and MnSOD genes: a meta-analysis of pharmacogenetic interactions

Despite accumulating evidence pointing to a genetic basis for tardive dyskinesia, results to date have been inconsistent owing to limited statistical power and limitations in molecular genetic methodology. A Medline, EMBASE and PsychINFO search for literature published between 1976 and June 2007 was performed, yielding 20 studies from which data were extracted for calculation of pooled estimates using meta-analytic techniques. Evidence from pooled data for genetic association with tardive dyskinesia (TD) showed (1) in COMTval158met, using Val–Val homozygotes as reference category, a protective effect for Val–Met heterozygotes (OR=0.63, 95% CI: 0.46–0.86, P=0.004) and Met carriers (OR=0.66, 95% CI: 0.49–0.88, P=0.005); (2) in Taq1A in DRD2, using the A1 variant as reference category, a risk-increasing effect for the A2 variant (OR=1.30, 95% CI: 1.03–1.65, P=0.026), and A2–A2 homozygotes using A1–A1 as reference category (OR=1.80, 95% CI: 1.03–3.15, P=0.037); (3) in MnSOD Ala–9Val, using Ala–Ala homozygotes as reference category, a protective effect for Ala–Val (OR=0.37, 95% CI: 0.17–0.79, P=0.009) and for Val carriers (OR=0.49, 95% CI: 0.24–1.00, P=0.047). These analyses suggest multiple genetic influences on TD, indicative of pharmacogenetic interactions. Although associations are small, the effects underlying them may be subject to interactions with other loci that, when identified, may have acceptable predictive power. Future genetic research will take advantage of new genomic knowledge.

Evidence that familial liability for psychosis is expressed as differential sensitivity to cannabis - an analysis of patient-sibling and sibling-control pairs

CONTEXT Individual differences in cannabis sensitivity may be associated with genetic risk for psychotic disorder. OBJECTIVES To demonstrate and replicate, using 2 conceptually different genetic epidemiological designs, that (familial) liability to psychosis is associated with sensitivity to cannabis. DESIGN, SETTING, AND PARTICIPANTS Sibling-control and cross-sibling comparisons using samples of patients with a psychotic disorder (n = 1120), their siblings (n = 1057), and community controls (n = 590) in the Netherlands and Flanders. MAIN OUTCOME MEASURES Positive and negative schizotypy using the Structured Interview for Schizotypy-Revised (for siblings and controls) and self-reported positive and negative psychotic experiences using the Community Assessment of Psychic Experiences (for siblings and patients). Cannabis use was assessed as current use (by urinalysis) and lifetime frequency of use (by Composite International Diagnostic Interview). RESULTS In the sibling-control comparison, siblings displayed more than 15 times greater sensitivity to positive schizotypy associated with particularly current cannabis use by urinalysis (adjusted B = 0.197, P < .001) than controls (adjusted B = 0.013, P = .86) (P interaction = .04) and a similar difference in sensitivity to its effect on negative schizotypy (siblings: adjusted B = 0.120, P < .001; controls: B = -0.008, P = .87; P interaction = .03). Similarly, siblings exposed to cannabis resembled their patient relative nearly 10 times more closely in the positive psychotic dimension of the Community Assessment of Psychic Experiences (adjusted B = 0.278, P < .001) compared with nonexposed siblings (adjusted B = 0.025, P = .12) (P interaction < .001). No significant effect was apparent for the Community Assessment of Psychic Experiences negative domain, although the association was directionally similar (2 times more resemblance; P interaction = .17). Cross-sibling, cross-trait analyses suggested that the mechanism underlying these findings was moderation (familial risk increasing sensitivity to cannabis) rather than mediation (familial risk increasing use of cannabis). CONCLUSIONS Genetic risk for psychotic disorder may be expressed in part as sensitivity to the psychotomimetic effect of cannabis. Cannabis use may synergistically combine with preexisting psychosis liability to cause positive and negative symptoms of psychosis.

Minor physical anomalies in psychoses : associations with clinical and putative aetiological variables

This study of patients with functional psychoses set out to examine associations between minor physical anomalies (MPAs) and demographic, clinical, CT scan measures, and putative aetiological variables. 157 psychotic patients had minor physical anomalies assessed using a modified Waldrop scale. RDC diagnoses for these patients were: schizophrenia (n = 79), schizoaffective disorder (n = 31), mania (n = 24), major depression (n = 13), unspecified functional psychosis (n = 8), other organic psychosis (n = 2). 63 healthy white controls were also assessed with the modified Waldrop scale. Minor physical anomalies were not associated with any particular diagnosis. For white subjects, patients had significantly more MPAs than well controls. Anomalies of the palate were the most frequent item reported in patients and controls. For males, there was a weak association between the presence of MPAs and positive family history of a major psychiatric disorder. Those with MPAs required more frequent and longer psychiatric admissions, and showed impaired ability on a test sensitive to left parietal system function. Within the patient group, there were no associations between MPAs and gender, age at onset, negative symptoms, premorbid level of functioning, estimated premorbid intelligence, pregnancy and birth complications, and selected CT variables. Minor physical anomalies are found in a range of functional psychoses. There may be overlap between the various genes that predispose to psychiatric illness (especially in males) and those genes that predispose to developmental instability.

Psychosis with good prognosis in Afro-Caribbean people now living in the United Kingdom

Abstract Objectives: To compare the course and outcome of psychotic illness in a group of Afro-Caribbean patients resident in the United Kingdom and a group of white British patients. Design: Cohort study of consecutive admissions followed up for four years. Subjects: 113 patients with psychotic illness of recent onset admitted to two south London hospitals. Main outcome measures: Course of illness, history of self harm, social disability, treatment received, and hospital use adjusted for socioeconomic origin. Results: The Afro-Caribbean group spent more time in a recovered state during the follow up period (adjusted odds ratio 5.0; 95% confidence interval 1.7 to 14.5), were less likely to have had a continuous illness (0.3; 0.1 to 0.8), were less at risk of self harm (0.2; 0.1 to 0.8), and were less likely to have been prescribed antidepressant treatment (0.3; 0.1 to 0.9). There were no differences in hospital use, but the Afro-Caribbean group had more involuntary admissions (8.9; 2.1 to 35.6) and more imprisonments over the follow up period (9.2; 1.6 to 52.3). Conclusions: Afro-Caribbean patients in the United Kingdom have a better outcome after psychiatric illness than do white people. The combination of high incidence and more benign course of illness of psychotic illness in this group may be due, at least in part, to a greater exposure to precipitants in the social environment.

Cerebral ventricle dimensions as risk factors for schizophrenia and affective psychosis: an epidemiological approach to analysis

A case-control study was undertaken of volumetric computerized tomographic scan measures in 216 consecutive admissions for functional psychosis and 67 healthy community controls. Odds ratio analysis demonstrated significant linear trends in the association between increasing lateral and third ventricle volumes, and both RDC schizophrenia (N = 121) and schizo-affective disorder (N = 41); cases were consistently associated with larger volumes than controls. There was an association between larger third, but not lateral, ventricle size in affective psychoses (N = 54). These associations were statistically independent of intracranial volume, sex, social class and ethnicity, factors which were significantly associated with ventricular measures in the controls. There was no evidence of a threshold corresponding to the notion of normal versus enlarged ventricles. Within the schizophrenia group, there were no large or significant associations between ventricle dimensions and age at onset, duration of illness or pre-morbid social functioning. Neither obstetric complications nor a family history of schizophrenia or other psychiatric illness was associated with large ventricles in these cases.