Does a history of cannabis use influence onset and course of schizophrenia?

INTRODUCTION: While evidence strongly supports a causal effect of cannabis on psychosis, it is less clear whether the symptom pattern, clinical course, and outcomes differ in cases of schizophrenia with and without a background of cannabis use. METHODS: Analysis of medical records from a longitudinal follow-up of Swedish conscripts with data on cannabis use in adolescence and subsequent incidence of schizophrenia. One hundred sixty patients with schizophrenia were assessed using the OPCRIT protocol. Cases were validated for diagnosis schizophrenia according to OPCRIT. RESULTS: Patients with a cannabis history (n = 32), compared to those without (n = 128), had an earlier age at onset, a higher number of hospital admissions and a higher total number of hospital days. There was no significant difference in type of onset and clinical symptom profiles between the groups. CONCLUSION: Our findings indicate that the disease burden of schizophrenia is greater in individuals who use cannabis during adolescence. Strengthening evidence on causality and teasing out long-term effects of pre-illness cannabis use from continued post-illness has clinical implications for improving schizophrenia outcomes.

Gender differences in the treatment of patients with borderline personality disorder.

It is debated whether men with borderline personality disorder (BPD) are less often treated for their disorder, compared to women, even when they have sought care. Here, the aim was to examine gender differences in the treatment of patients with BPD. Through linkage to Swedish health and administrative registers, we identified all patients diagnosed with BPD (n = 5530) in Stockholm County from 2012 to 2016. We ascertained information on sociodemographic characteristics, comorbid psychiatric diagnoses, and all mental health care utilization within inpatient and outpatient mental health care, including receipt of psychiatric medication and various psychological therapies. We identified 802 men and 4,728 women with BPD during the study period. Men with BPD were less likely than their female counterparts to be treated with psychotherapy as well as psychiatric medication. Most of the differences in treatment with psychological therapies were nonsignificant in the multivariate model, indicating they are likely the result of differences in sociodemographic variables and comorbidity between men and women with BPD. Men with BPD were in average 4 years older than women at the time of the first BPD diagnosis, had lower education, and were also more likely to receive social welfare support. In conclusion, few men are diagnosed with BPD and those who are diagnosed are likely to receive somewhat less psychiatric medication and psychological therapies compared to women. Researchers and clinicians need to focus more on men with BPD to improve help-seeking and recognition of this disabling condition in men and enable equal treatment. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Inequalities in Psychiatric Service Use and Mortality by Migrant Status Following a First Diagnosis of Psychotic Disorder: A Swedish Cohort Study of 1.3M People.

It is unclear whether inequalities in mental healthcare and mortality following the onset of psychosis exist by migrant status and region-of-origin. We investigated whether (1) mortality (including by major causes of death); (2) first admission type (inpatient or outpatient); (3) in-patient length of stay (LOS) at first diagnosis for psychotic disorder presentation, and; (4) time-to-readmission for psychotic disorder differed for refugees, non-refugee migrants, and by region-of-origin. We established a cohort of 1 335 192 people born 1984-1997 and living in Sweden from January 1, 1998, followed from their 14th birthday or arrival to Sweden, until death, emigration, or December 31, 2016. People with ICD-10 psychotic disorder (F20-33; N = 9399) were 6.7 (95% confidence interval [95%CI]: 5.9-7.6) times more likely to die than the general population, but this did not vary by migrant status (P = .15) or region-of-origin (P = .31). This mortality gap was most pronounced for suicide (adjusted hazard ratio [aHR]: 12.2; 95% CI: 10.4-14.4), but persisted for deaths from other external (aHR: 5.1; 95%CI: 4.0-6.4) and natural causes (aHR: 2.3; 95%CI: 1.6-3.3). Non-refugee (adjusted odds ratio [aOR]: 1.4, 95%CI: 1.2-1.6) and refugee migrants (aOR: 1.4, 95%CI: 1.1-1.8) were more likely to receive inpatient care at first diagnosis. No differences in in-patient LOS at first diagnosis were observed by migrant status. Sub-Saharan African migrants with psychotic disorder were readmitted more quickly than their Swedish-born counterparts (adjusted sub-hazard ratio [sHR]: 1.2; 95%CI: 1.1-1.4). Our findings highlight the need to understand the drivers of disparities in psychosis treatment and the mortality gap experienced by all people with disorder, irrespective of migrant status or region-of-origin.

Suicide risk in people with post-traumatic stress disorder: A cohort study of 3.1 million people in Sweden.

BACKGROUND: It is unclear whether post-traumatic stress disorder [PTSD] is associated with suicide risk in the general population, whether this differs by sex, or what the population impact of PTSD is for suicide. METHODS: We constructed a nationwide cohort of all people living in Sweden, born 1973-1997, followed from their 14th birthday (or immigration, if later) until suicide, other death, emigration or 31 December 2016. We used Cox proportional hazards regression to estimate hazard ratios [HR], and calculated the population impact of PTSD on suicide. We included sensitivity analyses to explore effects of outcome and exposure definitions, and to account for potential competing risks. RESULTS: Of 3,177,706 participants, 22,361 (0•7%) were diagnosed with PTSD, and 6,319 (0•2%) died by suicide over 49•2 million person-years. Compared with women and men without PTSD, suicide rates were 6•74 (95%CI: 5•61-8•09) and 3•96 (95%CI: 3•12-5•03) times higher in those with PTSD, respectively, after sociodemographic adjustment. Suicide rates remained elevated in women (HR: 2•61; 95%CI: 2•16-3•14) and men (HR: 1•67; 95%CI: 1•31-2•12) after adjustment for previous psychiatric conditions; attenuation was driven by previous non-fatal suicide attempts. Findings were insensitive to definitions or competing risks. If causal, 1•6% (95%CI: 1•2-2•1) of general population suicides could be attributed to PTSD, and up to 53.7% (95%CI: 46.1-60.2) in people with PTSD. LIMITATIONS: Residual confounding remains possible due to depressive and anxiety disorders diagnosed in primary care but unrecorded in these registers. CONCLUSIONS: Clinical guidelines for the management of people with PTSD should recognise increased suicide risks.

Childhood appendectomy and adult mental disorders: A population-based cohort study.

BACKGROUND: Recent studies suggest that disruption of the colonic microbiota homeostasis is associated with low-grade systemic inflammation and mental disorders. The cecal appendix may influence the homeostasis of the colonic microbiota. In this large population-based study, we investigated whether early removal of the appendix is associated with an increased risk of mental disorders later in life. MATERIALS AND METHODS: All Swedish individuals born between 1973 and 1992 (N = 1,937,488) were included and followed prospectively until December 31, 2016 for any psychiatric International Classification of Disease diagnosis from age 14 or later in life. The main exposure was defined as having a history of appendectomy before age 14 (N = 44,259); the second exposure, appendicitis before age 14 but without appendectomy (N = 1,542), and the third exposure studied was a history of hernia surgery before age 14 (N = 35,523). Control groups for each respective exposure were all unexposed individuals in the study population. RESULTS: Individuals exposed to appendectomy before age 14 had a 19% increased risk of depressive disorder (adjusted hazard ratio [aHR] = 1.19; 95% confidence interval [95% CI]: 1.15-1.23), 27% increased risk of bipolar affective disorder (aHR = 1.27; 95% CI: 1.17-1.37), and a 20% increased risk of an anxiety disorder (aHR = 1.20; 95% CI: 1.16-1.23) compared to individuals unexposed to childhood appendectomy. We found no association between appendectomy and increased risk of obsessive-compulsive disorder and schizophrenia and there was no association between appendicitis without appendectomy and mental disorders. The association between childhood hernia surgery and mental disorders later in life was small but significant. CONCLUSION: Childhood appendectomy, but not appendicitis without appendectomy, was associated with a significantly increased risk of mood and anxiety disorders in adulthood.

Neighborhood Socioeconomic Characteristics and Utilization of ADHD Medication in Schoolchildren: A Population Multilevel Study in Stockholm County.

Objective: To examine the effects of neighborhood socioeconomic disadvantage and ethnic composition on the utilization of ADHD medication in schoolchildren after accounting for individual- and family-level characteristics. Method: A cohort of all schoolchildren living in Stockholm County was prospectively followed for new prescriptions of ADHD medication (N = 276,955). Three-level logistic regression models were used with individual/family characteristics (e.g., immigrant background) at the first level and small area market statistics (SAMS) and municipality characteristics (i.e., socioeconomic disadvantage and ethnic composition) at the second and third level. Results: SAMS socioeconomic disadvantage was associated with increased utilization of ADHD medication. The utilization of ADHD medication was lower among immigrant children as compared with natives, and their odds of not utilizing medication increased as the degree of concentration of foreign-born increased. Conclusion: These results suggest that interventions at the neighborhood level may offer an additional route for the prevention of the disorder and/or alleviation of its consequences.

Birth month and later diagnosis of schizophrenia. A population-based cohort study in Sweden.

The objective of the present study was to examine if the monthly variation in births of individuals diagnosed with schizophrenia currently differs from that of unaffected individuals in Sweden. In an extensive linkage of Swedish national and regional population registers we here investigate the birth pattern of the population born 1940-97 (5,995,499 individuals) which included 30,684 individuals diagnosed with schizophrenia in the National Patient Register by December 31, 2016. Among 2,409,862 individuals born since 1973 we investigated potential confounding by co-variates associated with pregnancy and birth. We also compared the monthly birth pattern of 22,570 affected individuals to that of their 41,528 unaffected full siblings. We observe a significant birth excess of individuals with schizophrenia in December, HR 1.07 95%CI (1.01-1.13). Patients born in December received a registered diagnosis of schizophrenia at a slightly younger age than those born during other months. A number of co-variates were associated not only with schizophrenia but also varied across birth months. Inclusion of these in the models however had virtually no influence on the risk for schizophrenia associated with December birth. In comparisons between full siblings, the association between December birth and later diagnosis of schizophrenia remained, albeit slightly attenuated, HR 1.06 (0.99-1.12). Risk for schizophrenia associated with birth in December in Sweden during the study period does not appear to be fully explained by our investigated co-variates or factors shared between family members and may thus represent monthly/seasonal variation in environmental factors involved in the etiology of schizophrenia.

Association Between Atopic Dermatitis and Cardiovascular Disease: A Nationwide Register-based Case-control Study from Sweden.

The associations between atopic dermatitis (AD) and cardiovascular disease (CVD) are debated. The aim of this study was to investigate the association between AD and coronary artery disease or ischaemic stroke in a nationwide, register-based, case-control study (104,832 AD cases, 1,022,435 controls) based on linkage of Swedish national register data between 1968 and 2016. Patients were classified as having severe AD if they had received systemic pharmacotherapy for AD or had been treated in a dermatological ward with AD as the main diagnosis. Other AD was classified as non-severe. After multivariable adjustments for comorbidities and socioeconomic status, overall AD was associated with angina pectoris (adjusted odds ratio (aOR) 1.13, 95% confidence interval (CI) 1.08-1.19), but among males with severe AD this association was not found, compared with the general population. Male non-severe AD was associated with myocardial infarction (OR 1.15, 95% CI 1.07-1.23). Severe AD was associated with ischaemic stroke, with similar estimates in men and women (aOR 1.19, 95% CI 1.07-1.33). Subgroup analyses among women indicated smoking as an important risk factor among severe cases. Dia-betes mellitus, hyperlipidaemia, and hypertension were more prevalent in severe AD than in controls, and hyper-lipidaemia and hypertension were also more prevalent in non-severe AD than in controls. In conclusion, in this study, AD was associated with CVD, and this should be kept in mind, especially when managing patients with severe AD.

Systemic inflammation and intelligence in early adulthood and subsequent risk of schizophrenia and other non-affective psychoses: a longitudinal cohort and co-relative study.

BACKGROUND: Schizophrenia is associated with impaired neurodevelopment as indexed by lower premorbid IQ. We examined associations between erythrocyte sedimentation rate (ESR), a marker of low-grade systemic inflammation, IQ, and subsequent schizophrenia and other non-affective psychoses (ONAP) to elucidate the role of neurodevelopment and inflammation in the pathogenesis of psychosis. METHODS: Population-based data on ESR and IQ from 638 213 Swedish men assessed during military conscription between 1969 and 1983 were linked to National Hospital Discharge Register for hospitalisation with schizophrenia and ONAP. The associations of ESR with IQ (cross-sectional) and psychoses (longitudinal) were investigated using linear and Cox-regression. The co-relative analysis was used to examine effects of shared familial confounding. We examined mediation and moderation of effect between ESR and IQ on psychosis risk. RESULTS: Baseline IQ was associated with subsequent risk of schizophrenia (adjusted HR per 1-point increase in IQ = 0.961; 95% confidence interval (CI) 0.960-0.963) and ONAP (adjusted HR = 0.973; 95% CI 0.971-0.975). Higher ESR was associated with lower IQ in a dose-response fashion. High ESR was associated with increased risk for schizophrenia (adjusted HR = 1.14; 95% CI 1.01-1.28) and decreased risk for ONAP (adjusted HR = 0.85; 95% CI 0.74-0.96), although these effects were specific to one ESR band (7-10 mm/hr). Familial confounding explained ESR-IQ but not ESR-psychoses associations. IQ partly mediated the ESR-psychosis relationships. CONCLUSIONS: Lower IQ is associated with low-grade systemic inflammation and with an increased risk of schizophrenia and ONAP in adulthood. Low-grade inflammation may influence schizophrenia risk by affecting neurodevelopment. Future studies should explore the differential effects of inflammation on different types of psychosis.

Proportion of adults in the general population of Stockholm County who want gender-affirming medical treatment.

The number of patients presenting for care at gender clinics is increasing, yet the proportion of adults in the general population who want gender-affirming medical treatment remains essentially unknown. We measured the wish for cross-sex hormones or gender-affirming surgery, as well as other aspects of gender incongruence, among the general adult population of Stockholm County, Sweden. A population-representative sample of 50,157 Stockholm County residents ages 22 and older comprise the Stockholm Public Health Cohort. They were enrolled in 2002, 2006, and 2010 and followed-up in roughly 4-year intervals, with questions on health, lifestyle and social characteristics. In 2014, participants received the item "I would like hormones or surgery to be more like someone of a different sex." Two additional items concerned other aspects of gender incongruence: "I feel like someone of a different sex", and "I would like to live as or be treated as someone of a different sex." Each item had four answer options ("Not at all correct", "Somewhat or occasionally correct", "Quite correct", and "Absolutely correct"). For each item, any of the three affirmative answer choices were considered as some level of agreement. Calibration weights were used to estimate population-representative rates with 95% confidence intervals. The desire for cross-sex hormones or surgery was reported by 0.5% (95% CI, 0.4%-0.7%) of participants. Feeling like someone of a different sex was reported by 2.3% (95% CI, 2.1%-2.6%). Wanting to live as or be treated as a person of another sex was reported by 2.8% (95% CI, 2.4%-3.1%). These findings greatly exceed estimates of the number of patients receiving gender-affirming medical care. Clinicians must be prepared to recognize and care for patients experiencing discomfort due to gender incongruence and those who would like gender-affirming medical treatment.

Association of Childhood Infection With IQ and Adult Nonaffective Psychosis in Swedish Men: A Population-Based Longitudinal Cohort and Co-relative Study.

Importance: Associations between childhood infection, IQ, and adult nonaffective psychosis (NAP) are well established. However, examination of sensitive periods for exposure, effect of familial confounding, and whether IQ provides a link between childhood infection and adult NAP may elucidate pathogenesis of psychosis further. Objectives: To test the association of childhood infection with IQ and adult NAP, to find whether shared familial confounding explains the infection-NAP and IQ-NAP associations, and to examine whether IQ mediates and/or moderates the childhood infection-NAP association. Design, Setting, and Participants: Population-based longitudinal cohort study using linkage of Swedish national registers. The risk set included all Swedish men born between 1973 and 1992 and conscripted into the military until the end of 2010 (n = 771 698). We included 647 515 participants in the analysis. Measurement of Exposures: Hospitalization with any infection from birth to age 13 years. Main Outcomes and Measures: Hospitalization with an International Classification of Diseases diagnosis of NAP until the end of 2011. At conscription around age 18 years, IQ was assessed for all participants. Results: At the end of follow-up, the mean (SD) age of participants was 30.73 (5.3) years. Exposure to infections, particularly in early childhood, was associated with lower IQ (adjusted mean difference for infection at birth to age 1 year: -1.61; 95% CI, -1.74 to -1.47) and with increased risk of adult NAP (adjusted hazard ratio for infection at birth to age 1 year: 1.19; 95% CI, 1.06 to 1.33). There was a linear association between lower premorbid IQ and adult NAP, which persisted after excluding prodromal cases (adjusted hazard ratio per 1-point increase in IQ: 0.976; 95% CI, 0.974 to 0.978). The infection-NAP and IQ-NAP associations were similar in the general population and in full-sibling pairs discordant for exposure. The association between infection and NAP was both moderated (multiplicative, ß = .006; SE = 0.002; P = .02 and additive, ß = .008; SE = 0.002; P = .001) and mediated (ß = .028; SE = 0.002; P < .001) by IQ. Childhood infection had a greater association with NAP risk in the lower, compared with higher, IQ range. Conclusions and Relevance: Early childhood is a sensitive period for the effects of infection on IQ and NAP. The associations of adult NAP with early-childhood infection and adolescent IQ are not fully explained by shared familial factors and may be causal. Lower premorbid IQ in individuals with psychosis arises from unique environmental factors, such as early-childhood infection. Early-childhood infections may increase the risk of NAP by affecting neurodevelopment and by exaggerating the association of cognitive vulnerability with psychosis.

Trends in levels of self-reported psychological distress among individuals who seek psychiatric services over eight years: a comparison between age groups in three population surveys in Stockholm County.

BACKGROUND: Psychiatric service use has increased in Sweden and in other developed countries, particularly among young people. Possible explanations include lower threshold for help-seeking among young people, but evidence is scarce. METHODS: We analysed the 2002, 2006 and 2010 Stockholm public health surveys for changes in the mean level of psychological distress among adult users of psychiatric in- and outpatient services in four age groups: 18-24, 25-44, 45-64 and ≥65 years. Psychological distress was measured via the 12-item General Health Questionnaire (GHQ-12), using the Likert scoring method 0-1-2-3. In- and out-patient psychiatric service use within 6 months from the surveys was obtained from registers. RESULTS: The mean level of distress among young adults 18-24 years who utilize psychiatric services decreased between 2002 (mean GHQ-12 score, 95% confidence interval 20.5, 18.1-23.0) and 2010 (16.2, 14.6-17.7), while it remained fairly stable in older age groups. Results were similar in sex-stratified analyses, although the decrease was statistically significant only among young women 18-24 years. At the end of the follow-up, the level of distress among patients was similar for all age-groups. CONCLUSIONS: There were no differences between age groups in the level of distress when seeking care at the end of the follow-up period, supporting that there is no age-specific over- or under-consumption of psychiatric care in later years. However, the lowered threshold for help-seeking among young adults over time might have contributed to increases in psychiatric service use in the young age group. Public health policy and service delivery planning should consider the needs of the widening group of young users of psychiatric services.

Shift in Occupational Risk for Basal Cell Carcinoma from Outdoor to Indoor Workers: A Large Population-based Case-control Register Study from Sweden.

Basal cell carcinoma (BCC) is the most common form of cancer worldwide. Exposure of the skin to ultraviolet (UV) radiation, from sunlight and other sources, is the most important risk factor. The aim of this large-scale case-control study was to determine which occupations are associated with increased risk of BCC in Sweden. The case cohort comprised 74,247 patients with BCC and the control cohort comprised 574,055 subjects linked to population-based registers. Compared with the occupational category of farmers, foresters and gardeners we observed elevated risks of BCC for almost all occupational categories studied. Legal workers with odds ratio (OR) 2.69 (95% confidence interval (CI) 2.36-3.06), dentists OR 2.69 (95% CI 2.35-3.08) and physicians OR 2.47 (95% CI 2.24-2.74) had the highest risk for both sexes taken together. In conclusion, there appears to have been a change in the risk of BCC from outdoor to indoor occupations in Sweden, possibly related to exposure to UV radiation during leisure activities exceeding occupational sun exposure as the main cause of BCC in Sweden.

Discriminant validity of the 12-item version of the general health questionnaire in a Swedish case-control study.

BACKGROUND: The 12-item version of the General Health Questionnaire (GHQ-12) is widely used as a proxy for Affective Disorders in public health surveys, although the cut-off points for distress vary considerably between studies. The agreement between the GHQ-12 score and having a clinical disorder in the study population is usually unknown. AIMS: This study aimed to assess the criterion validity and to determine the sensitivity and specificity of the GHQ-12 in the Swedish population. METHODS: This study used 556 patient cases surveyed in specialized psychiatric care outpatient age- and sex-matched with 556 controls from the Stockholm Health Survey. Criterion validity for two scoring methods of GHQ-12 was tested using Receiver Operating Characteristics (ROC) analyses with Area Under the Curve (AUC) as a measure of agreement. Reference standard was (1) specialized psychiatric care and (2) current depression, anxiety or adjustment disorder. RESULTS: Both the Likert and Standard GHQ-12 scoring method discriminated excellently between individuals using specialized psychiatric services and healthy controls (Likert index AUC = 0.86, GHQ index AUC = 0.83), and between individuals with current disorder from healthy controls (Likert index AUC = 0.90, GHQ index AUC = 0.88). The best cut-off point for the GHQ index was ≥4 (sensitivity = 81.7 and specificity = 85.4), and for the Likert index ≥14 (sensitivity = 85.5 and specificity = 83.2). CONCLUSIONS: The GHQ-12 has excellent discriminant validity and is well suited as a non-specific measure of affective disorders in public mental health surveys.

Perinatal Exposure to Traffic-Related Air Pollution and Autism Spectrum Disorders.

BACKGROUND: Studies from the United States indicate that exposure to air pollution in early life is associated with autism spectrum disorders (ASD) in children, but the evidence is not consistent with European data. OBJECTIVE: We aimed to investigate the association between exposure to air pollution from road traffic and the risk of ASD in children, with careful adjustment for socioeconomic and other confounders. METHOD: Children born and residing in Stockholm, Sweden, during 1993-2007 with an ASD diagnosis were identified through multiple health registers and classified as cases (n = 5,136). A randomly selected sample of 18,237 children from the same study base constituted controls. Levels of nitrogen oxides (NOx) and particulate matter with diameter ≤ 10 µm (PM10) from road traffic were estimated at residential addresses during mother's pregnancy and the child's first year of life by dispersion models. Odds ratios (OR) and 95% confidence intervals (CI) for ASD with or without intellectual disability (ID) were estimated using logistic regression models after conditioning on municipality and calendar year of birth as well as adjustment for potential confounders. RESULT: Air pollution exposure during the prenatal period was not associated with ASD overall (OR = 1.00; 95% CI: 0.86, 1.15 per 10-µg/m3 increase in PM10 and OR = 1.02; 95% CI: 0.94, 1.10 per 20-µg/m3 increase in NOx during mother's pregnancy). Similar results were seen for exposure during the first year of life, and for ASD in combination with ID. An inverse association between air pollution exposure and ASD risk was observed among children of mothers who moved to a new residence during pregnancy. CONCLUSION: Early-life exposure to low levels of NOx and PM10 from road traffic does not appear to increase the risk of ASD. Citation: Gong T, Dalman C, Wicks S, Dal H, Magnusson C, Lundholm C, Almqvist C, Pershagen G. 2017. Perinatal exposure to traffic-related air pollution and autism spectrum disorders. Environ Health Perspect 125:119-126; http://dx.doi.org/10.1289/EHP118.

The influence of school on whether girls develop eating disorders.

BACKGROUND: Clinical anecdote suggests that rates of eating disorders (ED) vary between schools. Given their high prevalence and mortality, understanding risk factors is important. We hypothesised that rates of ED would vary between schools, and that school proportion of female students and proportion of parents with post-high school education would be associated with ED, after accounting for individual characteristics. METHOD: Multilevel analysis of register-based, record-linkage data on 55 059 females born in Stockholm County, Sweden, from 1983, finishing high school in 2002-10. Outcome was clinical diagnosis of an ED, or attendance at a specialist ED clinic, aged 16-20 years. RESULTS: The 5-year cumulative incidence of ED diagnosis aged 16-20 years was 2.4%. Accounting for individual risk factors, with each 10% increase in the proportion of girls at a school, the odds ratio for ED was 1.07 (1.01 to 1.13), P = 0.018. With each 10% increase in the proportion of children with at least one parent with post-high school education, the odds ratio for ED was 1.14 (1.09 to 1.19), P < 0.0001. Predicted probability of an average girl developing an ED was 1.3% at a school with 25% girls where 25% of parents have post-high school education, and 3.3% at a school with 75% girls where 75% of parents have post-high school education. CONCLUSIONS: Rates of ED vary between schools; this is not explained by individual characteristics. Girls at schools with high proportions of female students, and students with highly educated parents, have higher odds of ED regardless of individual risk factors.

Refugee migration and risk of schizophrenia and other non-affective psychoses: cohort study of 1.3 million people in Sweden.

OBJECTIVE: To determine whether refugees are at elevated risk of schizophrenia and other non-affective psychotic disorders, relative to non-refugee migrants from similar regions of origin and the Swedish-born population. DESIGN: Cohort study of people living in Sweden, born after 1 January 1984 and followed from their 14th birthday or arrival in Sweden, if later, until diagnosis of a non-affective psychotic disorder, emigration, death, or 31 December 2011. SETTING: Linked Swedish national register data. PARTICIPANTS: 1,347,790 people, including people born in Sweden to two Swedish-born parents (1,191,004; 88.4%), refugees (24,123; 1.8%), and non-refugee migrants (132,663; 9.8%) from four major refugee generating regions: the Middle East and north Africa, sub-Saharan Africa, Asia, and Eastern Europe and Russia. MAIN OUTCOME MEASURES: Cox regression analysis was used to estimate adjusted hazard ratios for non-affective psychotic disorders by refugee status and region of origin, controlling for age at risk, sex, disposable income, and population density. RESULTS: 3704 cases of non-affective psychotic disorder were identified during 8.9 million person years of follow-up. The crude incidence rate was 38.5 (95% confidence interval 37.2 to 39.9) per 100,000 person years in the Swedish-born population, 80.4 (72.7 to 88.9) per 100,000 person years in non-refugee migrants, and 126.4 (103.1 to 154.8) per 100,000 person years in refugees. Refugees were at increased risk of psychosis compared with both the Swedish-born population (adjusted hazard ratio 2.9, 95% confidence interval 2.3 to 3.6) and non-refugee migrants (1.7, 1.3 to 2.1) after adjustment for confounders. The increased rate in refugees compared with non-refugee migrants was more pronounced in men (likelihood ratio test for interaction χ(2) (df=2) z=13.5; P=0.001) and was present for refugees from all regions except sub-Saharan Africa. Both refugees and non-refugee migrants from sub-Saharan Africa had similarly high rates relative to the Swedish-born population. CONCLUSIONS: Refugees face an increased risk of schizophrenia and other non-affective psychotic disorders compared with non-refugee migrants from similar regions of origin and the native-born Swedish population. Clinicians and health service planners in refugee receiving countries should be aware of a raised risk of psychosis in addition to other mental and physical health inequalities experienced by refugees.

The influence of school in the development of eating disorders: a record-linkage study.

BACKGROUND: Clinical impression is that rates of eating disorders vary between schools; we are not aware of any previous research on this topic. We aimed to investigate whether rates of eating disorders in 16-20-year-old girls vary between upper secondary schools, and to test the hypothesis that school characteristics are associated with rates of eating disorders, even after accounting for characteristics of individual students. METHODS: This multilevel longitudinal study made use of record-linkage data from Stockholm County, Sweden. Participants were 55 824 Swedish-born girls completing secondary education in 2001-10 at 409 schools. Outcome was any diagnosed eating disorder at 16-20 years, as defined by an ICD (9 or 10) or DSM-IV code, or inferred from an appointment at a specialist eating disorder clinic. Multilevel modelling was used to separate individual and school level effects. The Stockholm Regional Ethical Review Board approved the study. FINDINGS: A 4·4% variation in incidence of eating disorders between schools was seen; after taking individual risk factors into account variation between schools was 2·9% (95% CI 1·5-5·0). Schools with a higher proportions of girls than boys had an increased incidence of eating disorders: for each 10% increase in the proportion of girls at a school, the odds ratio for eating disorders was 1·07 (95% CI 1·01-1·13, p=0·017). For each 10% increase in the proportion of parents with post-secondary education, the odds ratio for eating disorders was 1·14 (1·09-1·19, p<0·0001). INTERPRETATION: Our findings show that the contextual aspects of a school environment are associated with increased incidence of eating disorders. Incidence rates of eating disorders are higher in schools characterised by a high proportion of female students and of students with highly educated parents. To our knowledge, this is the first study to investigate whether rates of eating disorders vary between schools; however, use of registry data means that individuals who did not seek treatment would not have been studied. FUNDING: HB was supported by a Wellcome Trust Institutional Strategic Support Fund (via the Elizabeth Blackwell Institute).

Hospital admission with infection during childhood and risk for psychotic illness--a population-based cohort study.

A growing body of literature suggests that exposure to infections, particularly maternal infections, during pregnancy confers risk for later development of psychotic disorder. Though brain development proceeds throughout childhood and adolescence, the influence of infections during these ages on subsequent psychosis risk is insufficiently examined. The aim of this study was to investigate the potential association between infections during childhood and nonaffective psychoses in a large population-based birth cohort with follow up long enough to include peak incidence of nonaffective psychosis. We included all individuals born in Sweden between 1973 and 1985, (N = 1172879), with follow up on first time inpatient care with nonaffective psychosis from age 14 years until 2006, (N = 4638). Following adjustment for differences in sex, socioeconomic status, family history of psychosis, and hospital admissions involving noninfectious, nonpsychiatric care, we observed a small but statistically significant association between hospital admissions for infections, in general, throughout childhood (0-13 years) and a later diagnosis of nonaffective psychosis, hazard ratio (HR) = 1.10 (95% CI 1.03-1.18), and this association seemed to be driven by bacterial infection, HR = 1.23 (95% CI 1.08-1.40). Bacterial infections and central nervous system infections during preadolescence (10-13 years) conferred the strongest risk, HR 1.57 (95% CI 1.21-2.05) and HR 1.96 (95% CI 1.05-3.62), respectively. Although preadolescence appeared to be a vulnerable age period, and bacterial infection the most severe in relation to psychosis development, the present findings can also indicate an increased susceptibility to hospital admission for infections among children who will later develop nonaffective psychosis due to social or familial/genetic factors.