There is a substantial body of literature on environmental risk associated with schizophrenia. Most research has largely been conducted in Europe and North America, with little representation of the rest of the world; hence generalisability of findings is questionable. For this reason, we performed a mapping review of studies on environmental risk for schizophrenia spectrum disorders, recording the country where they were conducted, and we linked our findings with publicly available data to identify correlates with the uneven global distribution. Our aim was to evaluate how universal is the ‘common knowledge’ of environmental risk for psychosis collating the availability of evidence across different countries and to generate suggestions for future research identifying gaps in evidence.

We performed a systematic search and mapping of studies in the PubMed and PsycINFO electronic databases reporting on exposure to environmental risk for schizophrenia including obstetric complications, paternal age, migration, urbanicity, childhood trauma, and cannabis use and subsequent onset of schizophrenia spectrum disorders. This search focused on articles published from the date of the first available publication until 31 May 2023. We recorded the country where they were conducted. We downloaded publicly available data on population size, measures of wealth, medical provisions, research investment, and of quality research outputs per country and performed regression analyses of each predictor with the number of studies and recruited cases in each country.

We identified 308 publications that included a sample size of 445,000 patients with schizophrenia spectrum disorders. The majority were conducted in northern Europe and North America, with large parts of the world totally unrepresented. In the associations between the number of environmental risk studies for schizophrenia with potential predictors, we found that neither population nor wealth or research investment were strong predictors of research outputs in the field. Interestingly, the stronger correlations were found for number of researchers per population and for indicators of top-end scientific achievements, such as number of Nobel laureates per country.

Our results demonstrate a gap of knowledge due to the underrepresentation of studies on environmental risk of schizophrenia spectrum disorders in large parts of the world. This has implications not only in the generalisability of any findings from research conducted in the Northern hemisphere but also in our ability to progress in efforts to make causal inferences about biological pathways to schizophrenia. These findings reinforce the need to focus research on populations that are underrepresented in research and underserved in health care.

Suicide rates in the United States have been increasing, necessitating an understanding of demographic variations by ethnicity, age, sex and method to inform effective prevention strategies.

To dissect suicide rates in the US population from 2001 to 2023 by age, sex, ethnicity, and method.

This retrospective observational study utilized suicide data and population statistics from the CDC’s WISQARS database for the years 2001 (n = 30,418), 2018 (n = 48,132), 2020 (n = 45,721) and 2023 (n = 49,014). Cases were stratified by age, sex, ethnicity, and suicide method to assess trends and demographic differences.

From 2001 to 2023, the overall US suicide rate rose from 10.7 to 14.6 per 100,000, with a temporary decrease in 2019 and 2020 (14.4 and 13.8, respectively). The primary driver of the increase was firearm-related suicides among White males, contributing 25.8% of the rise from 2001 to 2018 and 51.6% from 2020 to 2023. Decline between 2018 and 2020 was mainly due to reductions in firearm and drug-related suicides among White males, but firearm suicides surged again from 2020 to 2023. Additionally, firearm suicides among ethnic minorities, especially Black/African-American males, accounted for 14.0% of the increase during 2020–2023. Drug-related suicides also increased by 8.6% among White females aged 45 and older in the same period.

Firearm suicides are the leading factor in the changing suicide rates in the United States from 2001 to 2023, alongside rising drug-related suicides among White females. These trends highlight the necessity for targeted prevention efforts that consider demographic-specific factors and method accessibility.

The environment shapes the risk of psychosis. In particular, urbanicity, deprivation or inequality, migrant density and cannabis availability may not only influence psychosis incidence, but also the characteristics of individuals who arrive at clinical services. This study examined how socioeconomic factors influence the incidence and characteristics of cases of First-Episode Psychosis (FEP).

We analysed prospective data collected from the FEP early detection programme of Emilia-Romagna, a high-income Italian region. Participants were 1240 individuals aged 18–35 years, who presented at the public healthcare services for a FEP. Exposures were derived from area-level data of 331 municipalities. We used population density, socioeconomic deprivation, educational deprivation, economic inequality, migrant density (proportion of migrants), frequent cannabis use (proportion of people aged 15–19 years old who reported frequent cannabis use). Outcome measures were FEP incidence (cases/100 000 inhabitants at risk per year) and characteristics (age of onset, migrant status, unemployment, substance use, treatment lag [DUP], family and resource problems). We reviewed pertinent literature, and formulated a Directed Acyclic Graph to present causal assumptions and provide adjustment sets for Bayesian spatial and multilevel models of social causation. To compare the effects of different exposures, we computed Average Marginal Effects and report the outcome changes that correspond to one standard deviation change of the exposure, incidence rate ratios (IRR) or odds ratios (OR).

The exposures and incidence of FEP displayed heterogeneous spatial distribution, with no spatially organized pattern. Accordingly, incidence and characteristics were best modelled as non-spatial, three-level hierarchical models. The incidence of FEP was influenced by population density (IRR, 1.14; 95% CrI, 1.03; 1.29), educational deprivation (IRR, 1.15; 95% CrI, 1.02; 1.31) and frequent cannabis use (IRR, 1.31; 95% CrI, 0.98; 1.82), more than socioeconomic deprivation. Higher migrant density in an area shortened the DUP on average by 3.4 months (95% CrI, −1.122; 0.76), while an increase of cannabis use of one standard deviation increased the DUP of 12.9 months (95% CrI, −2.86; 6229). Socioeconomic deprivation increased the likelihood of FEP cases being substance users (OR, 1.12; 95% CrI, 1.01; 1.26), while population density decreased it (OR, 0.91; 95% CrI, 0.83; 1.00).

Area-level socioeconomic features affect both the incidence and the characteristics of FEP, including the probability of individual being migrants, substance users or having a different DUP. Educational deprivation may function as a proxy for culture- or cognitive-related factors. Area-level socioeconomic data may inform public healthcare strategies for early identification and availability of tertiary clinical services.

The British Paediatric Surveillance Unit of the UK Royal College of Paediatrics and Child Health contacts participating consultant paediatricians each month to survey whether particular rare conditions or events have been seen in their services. This national surveillance of rare paediatric events has allowed a large amount of research into multiple paediatric conditions. In 2009, the Royal College of Psychiatrists established a similar system – the Child and Adolescent Psychiatry Surveillance System (CAPSS) – to survey consultant psychiatrists in UK and Ireland. Since many conditions involve mental and physical health features, seven studies have been run using reporting to both systems, with simultaneous surveillance across both paediatricians and psychiatrists. Given the desire by policymakers, commissioners and clinicians for well-integrated physical and mental healthcare (‘joined-up working’), and if the surveillance systems were functioning well, the CAPSS Executive expected high rates of parallel reporting of individual patients to the two systems. The current study synthesises the rates of parallel reporting of cases to those two systems. We assimilate rates of parallel reporting across the seven studies using figures that have already been published, and by contacting contributing research groups directly where the relevant figures are not currently published. No new primary data were collected.

Of the 1211 confirmed cases, 47 (3.9%) were reported by both psychiatrists and paediatricians. No parallel reporting occurred in four of the seven studies.

Our findings raise questions about whether joined-up working in mental and physical healthcare is happening in practice. Research into challenges to obtaining comprehensive surveillance will help epidemiologists improve their use of surveillance and control for biases.

Few studies have examined attention-deficit/hyperactivity disorder (ADHD) symptoms in middle- and older-aged adults. We aim to examine the phenotypic expression of ADHD symptoms in these age groups.

This study comprised a random sample (N = 1,562) from the US Health and Retirement Study 2016, a representative US sample aged 50 years and over. ADHD symptoms were assessed based on the Adult ADHD Self-Report Scale.

In the primary analysis, 10 competing confirmatory factor analytic models of ADHD symptoms in middle- and older-aged adults were compared. The best-fitting model was hierarchical with a general ADHD factor at the apex and underneath symptom factors of inattention, hyperactivity, and impulsivity (ꭓ2 = 319.34, df = 91.71, P = 0.00, TLI = 0.98, CFI = 0.96, RMSEA = 0.04, 95% CI = 0.04–0.05). In complementary analyses, this model was a satisfactory fit to the data: (1) in individuals without a history of cognitive impairment or dementia, and when the general ADHD factor was specified to load on (2) cognitive function, (3) depressive symptoms (which showed adequate fit), and (4) ADHD polygenic scores, (5) in middle- and older-aged adults, and (6) when weighted to represent the US population.

These results imply a hierarchical representation of ADHD symptoms in middle- and older-aged adults consisting of a general factor at the apex with neurocognitive and genetic correlates and underneath symptom factors of inattention, hyperactivity, and impulsivity. Collectively, this model offers a novel framework to study the mechanisms of ADHD symptoms in middle- and older-aged adults and points to treatment targets.

Specific phobias are common in the community, and much is known from epidemiological surveys about their subtypes and sex ratio.

To determine the subtypes and sex ratio in a treatment-seeking sample of people with a specific phobia.

Patients with a specific phobia were identified by a retrospective search of clinical case records from patient notes in electronic health records at the South London and Maudsley NHS Foundation Trust (the largest secondary mental healthcare provider in Europe).

We identified 1017 patients over 5 years as having a specific phobia. The adult female to male sex frequency ratio for having any specific phobia was 3.9, with the ratio of specific phobia subtypes ranging from 2.4 (natural environment) to 8.2 (animal). The child female to male ratio of specific phobia subtypes ranged from 0.7 (natural environment) to 1.8 (other subtypes). Phobia of vomiting was the most common specific phobia presenting in both adults (n = 161, 17.8% of all specific phobias) and children (n = 26, 23.4%). In adults with a phobia of vomiting, the female to male ratio was 9.1 compared with 3.4 in all other specific phobias, and 4.2 versus 0.98 for children.

There is a stark contrast between the apparent prevalence of phobia of vomiting in epidemiological surveys and being the most common presentation clinically. A very high female to male ratio in phobia of vomiting and animals in adults seeking treatment is also in contrast to findings in the community. This has implications for clinician training and public education.

About one-third of South African women have clinically significant symptoms of postpartum depression (PPD). Several socio-demographic risk factors for PPD exist, but data on medical and obstetric risk factors remain scarce for low- and middle-income countries and particularly in sub-Saharan Africa. We aimed to estimate the proportion of women with PPD and investigate socio-demographic, medical and obstetric risk factors for PPD among women receiving private medical care in South Africa (SA).

In this longitudinal cohort study, we analysed reimbursement claims from beneficiaries of an SA medical insurance scheme who delivered a child between 2011 and 2020. PPD was defined as a new International Classification of Diseases, 10th Revision diagnosis of depression within 365 days postpartum. We estimated the frequency of women with a diagnosis of PPD. We explored several medical and obstetric risk factors for PPD, including pre-existing conditions, such as HIV and polycystic ovary syndrome, and conditions diagnosed during pregnancy and labour, such as gestational diabetes, pre-term delivery and postpartum haemorrhage. Using a multivariable modified Poisson model, we estimated adjusted risk ratios (aRRs) and 95% confidence intervals (CIs) for factors associated with PPD.

Of the 47,697 participants, 2,380 (5.0%) were diagnosed with PPD. The cumulative incidence of PPD increased from 0.8% (95% CI 0.7–0.9) at 6 weeks to 5.5% (5.3–5.7) at 12 months postpartum. PPD risk was higher in individuals with history of depression (aRR 3.47, 95% CI [3.14–3.85]), preterm delivery (1.47 [1.30–1.66]), PCOS (1.37 [1.09–1.72]), hyperemesis gravidarum (1.32 [1.11–1.57]), gestational hypertension (1.30 [1.03–1.66]) and postpartum haemorrhage (1.29 [0.91–1.85]). Endometriosis, HIV, gestational diabetes, foetal stress, perineal laceration, elective or emergency C-section and preeclampsia were not associated with a higher risk of PPD.

The PPD diagnosis rate was lower than anticipated, based on the PPD prevalence of previous studies, indicating a potential diagnostic gap in SA’s private sector. Identified risk factors could inform targeted PPD screening strategies.

People with opioid use disorder (OUD) have substantially higher standardised mortality rates compared with the general population. However, lack of individualised prognostic information presents challenges in personalisation of addiction treatment delivery.

To develop and validate the first prognostic models to estimate 6-month all-cause and drug-related mortality risk for people diagnosed with OUD using indicators recorded at baseline assessment in addiction services in England.

Thirteen candidate prognostic variables, including sociodemographic, injecting status and health and mental health factors, were identified from nationally linked addiction treatment, hospital admission and death records from 1 April 2013 to 1 April 2022. Multivariable Cox regression models were developed with a fractional polynomial approach for continuous variables, and missing data were addressed using multiple imputation by chained equations. Validation was undertaken using bootstrapping methods. Discrimination was assessed using Harrel’s C and D statistics alongside examination of observed-to-predicted event rates and calibration curve slopes.

Data were available for 236 064 people with OUD, with 2427 deaths due to any cause, including 1289 due to drug-related causes. Both final models demonstrated good optimism-adjusted discrimination and calibration, with all-cause and drug-related models, respectively, demonstrating Harrell’s C statistics of 0.73 (95% CI 0.71–0.75) and 0.74 (95% CI 0.72–0.76), D-statistics of 1.01 (95% CI 0.95–1.08) and 1.07 (95% CI 0.98–1.16) and calibration slopes of 1.01 (95% CI 0.95–1.08) and 1.01 (95% CI 0.94–1.10).

We developed and internally validated Roberts’ OUD mortality risk, with the first models to accurately quantify individualised absolute 6-month mortality risks in people with OUD presenting to addiction services. Independent validation is warranted to ensure these models have the optimal utility to assist wider future policy, commissioning and clinical decision-making.