Migration is an established risk factor for developing a psychotic disorder in countries with a long history of migration. Less is known for countries with only a recent history of migration. This study aimed to determine the risk for developing a psychotic disorder in migrants to the Republic of Ireland.

We included all presentations of first-episode psychosis over 8.5 years to the DETECT Early Intervention for psychosis service in the Republic of Ireland (573 individuals aged 18–65, of whom 22% were first-generation migrants). Psychotic disorder diagnosis relied on SCID. The at-risk population was calculated using census data, and negative binomial regression was used to estimate incidence rate ratios.

The annual crude incidence rate for a first-episode psychotic disorder in the total cohort was 25.62 per 100000 population at risk. Migrants from Africa had a nearly twofold increased risk for developing a psychotic disorder compared to those born in the Republic of Ireland (IRR = 1.83, 95% CI 1.11–3.02, p = 0.02). In contrast, migrants from certain Asian countries had a reduced risk, specifically those from China, India, Philippines, Pakistan, Malaysia, Bangladesh and Hong Kong (aIRR = 0.36, 95% CI 0.16–0.81, p = 0.01).

Further research into the reasons for this inflated risk in specific migrant groups could produce insights into the aetiology of psychotic disorders. This information should also be used, alongside other data on environmental risk factors that can be determined from census data, to predict the incidence of psychotic disorders and thereby resource services appropriately.

Early intervention in psychosis is a complex intervention, usually delivered in a specialist stand-alone setting, which aims to improve outcomes for people with psychosis. Previous studies have been criticised because the control used did not accurately reflect actual practice.

To evaluate the cost-effectiveness of early intervention by estimating the incremental net benefit (INB) of an early-intervention programme, delivered in a real-world setting. INB measures the difference in monetary terms between alternative interventions.

Two contemporaneous incidence-based cohorts presenting with first-episode psychosis, aged 18–65 years, were compared. Costs and outcomes were measured over 1 year. The main outcome was avoidance of a relapse that required admission to hospital or home-based treatment.

From the health sector perspective, the probability that early intervention was cost-effective was 0.77. The INB was €2465 per person (95% CI − €4418 to €9347) when society placed a value of €6000, the cost of an in-patient relapse, on preventing a relapse requiring admission or home care. Following adjustment, the probability that early intervention was cost-effective was 1, and the INB to the health sector was €3105 per person (95% CI −€8453 to €14 663). From a societal perspective, the adjusted probability that early intervention was cost-effective was 1, and the INB was €19 928 per person (95% CI − €2075 to €41 931).

Early intervention has a modest INB from the health sector perspective and a large INB from the societal perspective. The perspective chosen is critical when presenting results of an economic evaluation of a complex intervention.

To examine the use of vitamin D supplements during infancy among the participants in an international infant feeding trial.

Longitudinal study.

Information about vitamin D supplementation was collected through a validated FFQ at the age of 2 weeks and monthly between the ages of 1 month and 6 months.

Infants (n 2159) with a biological family member affected by type 1 diabetes and with increased human leucocyte antigen-conferred susceptibility to type 1 diabetes from twelve European countries, the USA, Canada and Australia.

Daily use of vitamin D supplements was common during the first 6 months of life in Northern and Central Europe (>80 % of the infants), with somewhat lower rates observed in Southern Europe (>60 %). In Canada, vitamin D supplementation was more common among exclusively breast-fed than other infants (e.g. 71 % v. 44 % at 6 months of age). Less than 2 % of infants in the USA and Australia received any vitamin D supplementation. Higher gestational age, older maternal age and longer maternal education were study-wide associated with greater use of vitamin D supplements.

Most of the infants received vitamin D supplements during the first 6 months of life in the European countries, whereas in Canada only half and in the USA and Australia very few were given supplementation.