Epidemiological evidence shows a concerning rise in youth mental health difficulties over the past three decades. Most evidence, however, comes from countries in Europe or North America, with far less known about changes in other global regions. This study aimed to compare adolescent mental health across two population-based cohorts in the UK, and two population-based cohorts in Pelotas, Brazil.

Four population-based cohorts with identical mental health measures were compared. In Brazil, these included the 1993 Pelotas Birth Cohort and the 2004 Pelotas Birth Cohort. In the UK, cohorts included the Avon Longitudinal Study of Parents and Children, and the Millennium Cohort Study. Mental health was measured in all cohorts using identical, parent-rated scores from the Strengths and Difficulties Questionnaire (SDQ). This was assessed in both countries over approximately the same time periods, when adolescents were aged 11 (2004 vs 2015 in Brazil, and 2003 vs 2012 in the UK), with follow-up analyses focused on outcomes in later adolescence.

Mental health problems were higher in the UK for adolescents born in the early 2000s compared to those born in the early 1990s. In Pelotas, the opposite was found, whereby problems were lower for adolescents born in the early 2000s compared to those born in the early 1990s. Despite these promising reductions in mental health problems in Pelotas over time, SDQ scores remained higher in Pelotas compared to the UK.

Our study represents the first to compare two population-based cohorts in the UK, and two population-based cohorts in Pelotas, Brazil, to understand how mental health problems have changed over time across the two settings. Our findings provide the most up-to-date insight into population-level rates of youth mental health problems in Pelotas, and shed novel insight into how these have changed over the last two decades in comparison to the UK. In doing so, our study provides a tentative first step towards understanding youth mental health over time at a more global scale, and presents a valuable opportunity to examine putative contributors to differences across time.

Adolescence is the peak life stage for the development of mental illness. Whole-school approaches to mental health and well-being, modelled on the World Health Organization’s Health-Promoting Schools Framework, hold vast potential in this developmentally sensitive period. However, the evidence base for these interventions is inconclusive.

Our study examines the effectiveness of The Resilience Project School Partnership Program, a whole-school intervention involving students, teachers and parents, centred around concepts of gratitude, empathy, emotional literacy and mindfulness.

A quasi-experimental study with an intervention and a control arm was used to evaluate the programme in 40 149 students across 102 schools in 2023. Data collected included sociodemographic information and outcomes derived from validated scales, comprising life satisfaction, hope, coping skills, anxiety and depression. Intervention schools were stratified by the number of years they had implemented the programme, and mixed-effects regression models were used to evaluate the programme.

After adjusting for confounders, participants at schools who had been implementing the programme for 6 years or longer demonstrated significantly better outcomes across all five domains (life satisfaction: B = 0.627, 95% CI 0.465–0.789; hope: B = 2.135, 95% CI 0.895–3.347; coping skills: B = 0.438, 95% CI 0.250–0.625; anxiety: odds ratio = 0.658, 95% CI 0.559–0.774; depression: odds ratio = 0.534, 95% CI 0.459–0.620). Only depression was significantly lower among participants at schools in their fourth or fifth year of implementing the programme (odds ratio = 0.941, 95% CI 0.935–0.948).

Our findings indicate that whole-school interventions may require long-term investment to realise their potential and highlight implementation duration as an important consideration for future evaluations of whole-school interventions.

Early pubertal timing is associated with depressive symptoms in girls, but studies in boys are limited and have yielded conflicting results.

N = 4,664 male participants from a UK birth cohort (Avon Longitudinal Study of Parents and Children – ALSPAC). Seven indicators of pubertal timing were measured repeatedly from 7 to 17 years (age at: peak height velocity, peak weight velocity, peak bone mineral content velocity, Tanner stage 3 pubic hair, Tanner stage 3 genitalia, axillary hair, and voice break), categorised into ‘early’, ‘on-time,’ and ‘late’ (mean ± 1 SD). Depressive symptoms (binary variable indicating higher versus lower levels) were assessed at 14 and 18 years, and depression (ICD-10 diagnosis) was assessed at 18 years. Multivariable logistic regression was used to examine associations between each indicator of pubertal timing and depressive symptoms/depression, adjusted for socioeconomic status (SES) and prepubertal body mass index (BMI).

Compared to males with normative pubertal development, the odds of depression at age 18 were higher in those with early age at peak height velocity (OR: 2.06; 95% CI 1.27–3.34), early age at peak weight velocity (OR: 2.10; 95% CI 1.16–3.79), and early age at Tanner genitalia stage 3 (OR: 1.81; 95% CI 1.01–3.26). There was no evidence for associations between pubertal timing and depressive symptoms at age 14 or 18.

We found evidence that males with an earlier pubertal timing had increased odds of depression at age 18. Early maturing boys could be targeted for interventions aimed at preventing depression.

Recent theories have implicated inflammatory biology in the development of psychopathology and maladaptive behaviors in adolescence, including suicidal thoughts and behaviors (STB). Examining specific biological markers related to inflammation is thus warranted to better understand risk for STB in adolescents, for whom suicide is a leading cause of death.

Participants were 211 adolescent females (ages 9–14 years; Mage = 11.8 years, SD = 1.8 years) at increased risk for STB. This study examined the prospective association between basal levels of inflammatory gene expression (average of 15 proinflammatory mRNA transcripts) and subsequent risk for suicidal ideation and suicidal behavior over a 12-month follow-up period.

Controlling for past levels of STB, greater proinflammatory gene expression was associated with prospective risk for STB in these youth. Similar effects were observed for CD14 mRNA level, a marker of monocyte abundance within the blood sample. Sensitivity analyses controlling for other relevant covariates, including history of trauma, depressive symptoms, and STB prior to data collection, yielded similar patterns of results.

Upregulated inflammatory signaling in the immune system is prospectively associated with STB among at-risk adolescent females, even after controlling for history of trauma, depressive symptoms, and STB prior to data collection. Additional research is needed to identify the sources of inflammatory up-regulation in adolescents (e.g., stress psychobiology, physiological development, microbial exposures) and strategies for mitigating such effects to reduce STB.

Cannabis is the most commonly used illicit substance in Ireland and globally. It is most likely to be used in adolescence, a period of biopsychosocial vulnerability to maladaptive behaviours. This study aims to investigate the risk and protective factors for cannabis use among adolescents.

This study is a secondary analysis of the cross-sectional Planet Youth survey (2021). The sample comprised 4,404 adolescents aged 15–16 from one urban and two rural areas in Ireland. The outcome of interest was current cannabis use, defined as cannabis use within the last 30 days. Independent variables i.e., risk and protective factors, were selected a priori following a literature review. Associations between cannabis use and the independent variables were explored using mixed-effects logistic regressions.

The prevalence of current cannabis use was 7.3% and did not differ significantly between males and females. In fully-adjusted models, significant risk factors for cannabis use were: Having peers that used cannabis (Adjusted Odds Ration (aOR) 10.17, 95% CI: 5.96–17.35); Parental ambivalence towards cannabis use (aOR 3.69, 95% CI: 2.41–5.66); Perception of cannabis as non-harmful (aOR 2.32,95% CI 1.56–£.45): Other substance use (aORs ranging from 2-67–3.15); Peer pressure to use cannabis (aOR 1.85,95% CI 1.05–3.26), and Low parental supervision (aOR 1.11, 95% CI: 1.01–1.22).

This study identified key individual, peer-to-peer and parental risk factors associated with adolescent cannabis use, several of which have the potential to be modified through drug prevention strategies.

A growing number of studies among adolescents have reported early maladaptive schemas (EMS) to associate with anxiety and depression within non-clinical samples. However, there is a gap of knowledge concerning clinical populations.

The current study’s aim was to explore the potential association between EMS domains and anxiety and depressive symptoms within clinical sample of adolescents.

The current study included 176 adolescent psychiatry out-patients. The EMS domains were measured with the Young Schema Questionnaire-Short Form 2-Extended (YSQ). Their association with anxiety symptoms (the Overall Anxiety Severity and Impairment Scale) and depressive symptoms (the Beck Depression Inventory II) were analysed with general linear models while controlling for significant confounding factors.

Depressive symptoms were associated with three of the four EMS domains: Disconnection and Rejection (η2p=0.047, p=0.005), Impaired Autonomy and Performance (η2p=0.074, p<0.001), and Impaired Limits (η2p=0.053, p=0.003). Anxiety symptoms were associated with two EMS domains: Impaired Autonomy and Performance (η2p=0.046, p=0.005) and Excessive Responsibility and Standards (η2p=0.054, p=0.002).

Various EMS domains were associated with depressive and anxiety symptoms among adolescent out-patients. Further studies are needed on the effect of EMSs on the treatment outcomes for depression and anxiety.

At a time of increased demand for specialist mental health services, a more nuanced understanding of how adolescents navigate systems of care and support is essential. We mapped ‘networks of care’ to explore patterns of mental health help-seeking alongside the perceived helpfulness of support accessed.

We examined data from 23 927 adolescents aged 11–18 years who participated in the 2023 OxWell Student Survey, an English school-based, repeated cross-sectional survey of mental health and wellbeing. Students self-reported past-year access to 18 types of support across informal (e.g. friends and family), semi-formal (e.g. school and charities), and formal (e.g. health and social care) domains, alongside how helpful they found the support. We used a network approach to explore interconnections between sources of support accessed and perceived helpfulness.

One in four (27.0%, 6449/23927) adolescents reported past-year access to mental health support, of which 56.7% (3658/6449) reported accessing multiple types. Informal networks were the most commonly accessed (23.1%, 5523/23927), followed by semi-formal (9.7%, 2317/23927) and formal (6.8%, 1623/23927) supports. Informal sources had high acceptability, with around 80–90% reporting them as helpful, whereas child and adolescent mental health services (CAMHS), helplines, and online supports were perceived to be the least helpful. The networks also identified groups who might not be optimally served by current systems, including gender diverse adolescents and adolescents who found mental health support from their parents unhelpful.

Adolescents are accessing mental health support across informal, semi-formal, and formal sources of care. Services can no longer be developed, delivered, or evaluated in isolation from these networks.