Mental health policy makers require evidence-based information to optimise effective care provision based on local need, but tools are unavailable.

To develop and validate a population-level prediction model for need for early intervention in psychosis (EIP) care for first-episode psychosis (FEP) in England up to 2025, based on epidemiological evidence and demographic projections.

We used Bayesian Poisson regression to model small-area-level variation in FEP incidence for people aged 16–64 years. We compared six candidate models, validated against observed National Health Service FEP data in 2017. Our best-fitting model predicted annual incidence case-loads for EIP services in England up to 2025, for probable FEP, treatment in EIP services, initial assessment by EIP services and referral to EIP services for ‘suspected psychosis’. Forecasts were stratified by gender, age and ethnicity, at national and Clinical Commissioning Group levels.

A model with age, gender, ethnicity, small-area-level deprivation, social fragmentation and regional cannabis use provided best fit to observed new FEP cases at national and Clinical Commissioning Group levels in 2017 (predicted 8112, 95% CI 7623–8597; observed 8038, difference of 74 [0.92%]). By 2025, the model forecasted 11 067 new treated cases per annum (95% CI 10 383–11 740). For every 10 new treated cases, 21 and 23 people would be assessed by and referred to EIP services for suspected psychosis, respectively.

Our evidence-based methodology provides an accurate, validated tool to inform clinical provision of EIP services about future population need for care, based on local variation of major social determinants of psychosis.

Evidence regarding the association between cannabis use and depression remain conflicting, especially as studies have not typically adopted a longitudinal design with a follow-up period that was long enough to adequately cover the risk period for onset of depression.

Males from the Cambridge Study in Delinquent Development (CSDD) (N = 285) were assessed seven times from age 8 to 48 years to prospectively investigate the association between cannabis use and risk of major depressive disorder (MDD). A combination of multiple analyses (logistic regression, Cox regression, fixed-effects analysis) was employed to explore the strength and direction of effect within different developmental stages.

Multiple regression analyses revealed that early-onset cannabis use (before age 18) but not late-onset cannabis use (after age 27) was associated with a higher risk and shorter time until a subsequent MDD diagnosis. This effect was present in high-frequency [(odds ratio (OR) 8.83, 95% confidence interval (CI) 1.29–70.79]; [hazard ratio (HR) 8.69, 95% CI 2.07–36.52)] and low-frequency early-onset users (OR 2.41, 95% CI 1.22–4.76; HR 2.09, 95% CI 1.16–3.74). Effect of increased frequency of cannabis use on increased risk of subsequent MDD was observed only for use during adolescence (age 14–18) but not at later life stages, while controlling for observed and non-unobserved time-invariant factors. Conversely, MDD in adulthood (age 18–32) was linked to a reduction in subsequent cannabis use (age 32–48).

The present findings provide evidence implicating frequent cannabis use during adolescence as a risk factor for later life depression. Future studies should further examine causality of effects in larger samples.

Changes in positive and negative symptom profiles during acute psychotic episodes may be key drivers in the pathway to violence. Acute episodes are often preceded by fluctuations in affect before psychotic symptoms appear and affective symptoms may play a more important role in the pathway than previously recognised.

We carried out a prospective cohort study of 409 male and female patients discharged from medium secure services in England and Wales to the community. Measures were taken at baseline (pre-discharge), 6 and 12 months post-discharge using the Positive and Negative Syndrome Scale. Information on violence was obtained using the McArthur Community Violence Instrument and Police National Computer.

The larger the shift in positive symptoms the more likely violence occurred in each 6-month period. However, shifts in angry affect were the main driving factor for positive symptom shifts associated with violence. Shifts in negative symptoms co-occurred with positive and conveyed protective effects, but these were overcome by co-occurring shifts in anger. Severe but stable delusions were independently associated with violence.

Intensification of angry affect during acute episodes of psychosis indicates the need for interventions to prevent violence and is a key driver of associated positive symptoms in the pathway to violence. Protective effects against violence exerted by negative symptoms are not clinically observable during symptom shifts because they are overcome by co-occurring anger.

There is growing risk from terrorism following radicalisation of young men. It is unclear whether psychopathology is associated.

To investigate the population distribution of extremist views among UK men.

Cross-sectional study of 3679 men, 18–34 years, in Great Britain. Multivariate analyses of attitudes, psychiatric morbidity, ethnicity and religion.

Pro-British men were more likely to be White, UK born, not religious; anti-British were Muslim, religious, of Pakistani origin, from deprived areas. Pro- and anti-British views were linearly associated with violence (adjusted odds ratio (OR) = 1.51, 95% CI 1.38–1.64, P<0.001, adjusted OR = 1.33, 95% CI 1.13–1.58, P<0.001, respectively) and negatively with depression (adjusted OR = 0.72, 95% CI 0.61–0.85, P<0.001, adjusted OR = 0.64, 95% CI 0.48–0.86, P = 0.003, respectively).

Men at risk of depression may experience protection from strong cultural or religious identity. Antisocial behaviour increases with extremism. Religion is protective but may determine targets of violence following radicalisation.

Some patients are at higher risk of contact with criminal justice agencies when experiencing a first episode of psychosis.

To investigate whether violence explains criminal justice pathways (CJPs) for psychosis in general, and ethnic vulnerability to CJPs.

Two-year population-based survey of people presenting with a first-episode of psychosis. A total of 481 patients provided information on pathways to psychiatric care. The main outcome was a CJP at first contact compared with other services on the care pathway.

CJPs were more common if there was violence at first presentation (odds ratio (OR) = 4.23, 95% CI 2.74–6.54, P<0.001), drug use in the previous year (OR = 2.28, 95% CI 1.50–3.48, P<0.001) and for high psychopathy scores (OR = 2.54, 95% CI 1.43–4.53, P = 0.002). Compared with White British, CJPs were more common among Black Caribbean (OR = 2.97, 95% CI 1.54–5.72, P<0.001) and Black African patients (OR = 1.95, 95% CI 1.02–3.72, P = 0.01). Violence mediated 30.2% of the association for Black Caribbeans, but was not a mediator for Black African patients. These findings were sustained after adjustment for age, marital status, gender and employment.

CJPs were more common in violent presentations, for greater psychopathy levels and drug use. Violence presentations did not fully explain ethnic vulnerability to CJPs.

Intergenerational continuities in criminal behaviour have been well documented, but the familial nature of psychopathic personality is less well understood.

To establish if there is an association between the psychopathic traits of a community sample of men and their offspring and whether psychosocial risk factors mediate this.

Participants of the Cambridge Study in Delinquent Development (n = 478 dyads) were assessed for psychopathy using the PCL: SV. Multilevel regression models were used to investigate intergenerational continuity and mediation models examined indirect effects.

The fathers' psychopathy was transmitted to both sons and daughters. The transmission of Factor 1 scores was mediated via the fathers' employment problems. For male offspring, the Factor 2 scores were mediated via the fathers' drug use, accommodation and employment problems. For female offspring, Factor 2 scores were mediated via the fathers' employment problems.

Understanding of the specific role of certain psychosocial risk factors may be useful in developing preventive measures for the development of psychopathy.

Forensic psychiatry services are expanding in England and Wales but require support from general services for patient after-care.

To compare outcomes following community after-care from forensic or general adult psychiatry services.

An observational comparison was made of case management following discharge from medium security in seven pre-reorganisation health regions of England and Wales, by forensic services (n=409) and general adult services (n=652). Criminal convictions, hospital readmissions and deaths were compared over a mean follow-up period of 6.2 years, adjusting for difference in case mix.

Forensic services did not supervise more high-risk patients in the community. Neither service was superior in outcome. More patients managed by general services died from natural causes.

Neither service was superior on measures of subsequent offending or hospitalisation. Specialist forensic after-care conveyed no added benefit. Case management may have been the same in both services.