Childhood bullying is a public health priority. We evaluated the effectiveness and costs of KiVa, a whole-school anti-bullying program that targets the peer context.

A two-arm pragmatic multicenter cluster randomized controlled trial with embedded economic evaluation. Schools were randomized to KiVa-intervention or usual practice (UP), stratified on school size and Free School Meals eligibility. KiVa was delivered by trained teachers across one school year. Follow-up was at 12 months post randomization. Primary outcome: student-reported bullying-victimization; secondary outcomes: self-reported bullying-perpetration, participant roles in bullying, empathy and teacher-reported Strengths and Difficulties Questionnaire. Outcomes were analyzed using multilevel linear and logistic regression models.

Between 8/11/2019–12/02/2021, 118 primary schools were recruited in four trial sites, 11 111 students in primary analysis (KiVa-intervention: n = 5944; 49.6% female; UP: n = 5167, 49.0% female). At baseline, 21.6% of students reported being bullied in the UP group and 20.3% in the KiVa-intervention group, reducing to 20.7% in the UP group and 17.7% in the KiVa-intervention group at follow-up (odds ratio 0.87; 95% confidence interval 0.78 to 0.97, p value = 0.009). Students in the KiVa group had significantly higher empathy and reduced peer problems. We found no differences in bullying perpetration, school wellbeing, emotional or behavioral problems. A priori subgroup analyses revealed no differences in effectiveness by socioeconomic gradient, or by gender. KiVa costs £20.78 more per pupil than usual practice in the first year, and £1.65 more per pupil in subsequent years.

The KiVa anti-bullying program is effective at reducing bullying victimization with small-moderate effects of public health importance.

The study was funded by the UK National Institute for Health and Care Research (NIHR) Public Health Research program (17-92-11). Intervention costs were funded by the Rayne Foundation, GwE North Wales Regional School Improvement Service, Children's Services, Devon County Council and HSBC Global Services (UK) Ltd.

‘Inhalants’ have been associated with poorer mental health in adolescence, but little is known of associations with specific types of inhalants.

We aimed to investigate associations of using volatile substances, nitrous oxide and alkyl nitrates with mental health problems in adolescence.

We conducted a cross-sectional analysis using data from 13- to 14-year-old adolescents across England and Wales collected between September 2019 and March 2020. Multilevel logistic regression examined associations between lifetime use of volatile substances, nitrous oxide and alkyl nitrates with self-reported symptoms of probable depression, anxiety, conduct disorder and auditory hallucinations.

Of the 6672 adolescents in the study, 5.1% reported use of nitrous oxide, 4.9% volatile solvents and 0.1% alkyl nitrates. After accounting for multiple testing, adolescents who had used volatile solvents were significantly more likely to report probable depressive (odds ratio = 4.59, 95% CI 3.58, 5.88), anxiety (odds ratio = 3.47, 95% CI 2.72, 4.43) or conduct disorder (odds ratio = 7.52, 95% CI 5.80, 9.76) and auditory hallucinations (odds ratio = 5.35, 95% CI 4.00, 7.17) than those who had not. Nitrous oxide use was significantly associated with probable depression and conduct disorder but not anxiety disorder or auditory hallucinations. Alkyl nitrate use was rare and not associated with mental health outcomes. Adjustment for use of other inhalants, tobacco and alcohol resulted in marked attenuation but socioeconomic disadvantage had little effect.

To our knowledge, this study provides the first general population evidence that volatile solvents and nitrous oxide are associated with probable mental health disorders in adolescence. These findings require replication, ideally with prospective designs.

Cannabis has been associated with poorer mental health, but little is known of the effect of synthetic cannabinoids or cannabidiol (often referred to as CBD).

To investigate associations of cannabis, synthetic cannabinoids and cannabidiol with mental health in adolescence.

We conducted a cross-sectional analysis with 13- to 14-year-old adolescents across England and Wales in 2019–2020. Multilevel logistic regression was used to examine the association of lifetime use of cannabis, synthetic cannabinoids and cannabidiol with self-reported symptoms of probable depression, anxiety, conduct disorder and auditory hallucinations.

Of the 6672 adolescents who participated, 5.2% reported using of cannabis, 1.9% reported using cannabidiol and 0.6% reported using synthetic cannabinoids. After correction for multiple testing, adolescents who had used these substances were significantly more likely to report a probable depressive, anxiety or conduct disorder, as well as auditory hallucinations, than those who had not. Adjustment for socioeconomic disadvantage had little effect on associations, but weekly tobacco use resulted in marked attenuation of associations. The association of cannabis use with probable anxiety and depressive disorders was weaker in those who reported using cannabidiol than those who did not. There was little evidence of an interaction between synthetic cannabinoids and cannabidiol.

To our knowledge, this study provides the first general population evidence that synthetic cannabinoids and cannabidiol are associated with probable mental health disorders in adolescence. These associations require replication, ideally with prospective cohorts and stronger study designs.

Many people with intellectual disabilities find it hard to control their anger and this often leads to aggression which can have serious consequences, such as exclusion from mainstream services and the need for potentially more expensive emergency placements.

To evaluate the effectiveness of a cognitive–behavioural therapy (CBT) intervention for anger management in people with intellectual disabilities.

A cluster-randomised trial of group-based 12-week CBT, which took place in day services for people with intellectual disabilities and was delivered by care staff using a treatment manual. Participants were 179 service users identified as having problems with anger control randomly assigned to either anger management or treatment as usual. Assessments were conducted before the intervention, and at 16 weeks and 10 months after randomisation (trial registration: ISRCTN37509773).

The intervention had only a small, and non-significant, effect on participants' reports of anger on the Provocation Index, the primary outcome measure (mean difference 2.8, 95% Cl −1.7 to 7.4 at 10 months). However, keyworker Provocation Index ratings were significantly lower in both follow-up assessments, as were service-user ratings on another self-report anger measure based on personally salient triggers. Both service users and their keyworkers reported greater usage of anger coping skills at both follow-up assessments and keyworkers and home carers reported lower levels of challenging behaviour.

The intervention was effective in improving anger control by people with intellectual disabilities. It provides evidence of the effectiveness of a CBT intervention for this client group and demonstrates that the staff who work with them can be trained and supervised to deliver such an intervention with reasonable fidelity.