Recently, there has been a significant rise in potency (% tetrahydrocannabinol (THC)) of cannabis products globally. As such, there is a need for a better understanding of the relationship between cannabis potency and mental health outcomes, especially in a developmentally vulnerable population such as adolescents and young adults.

The objective of this scoping review was to summarise existing literature investigating the potency of cannabis products as it relates to mental health outcomes in adolescents and young adults aged 14–25.

Systematic searches of MEDLINE, Embase, CINAHL and PsycINFO were conducted for relevant manuscripts up to October 2025. Following PRISMA-ScR guidelines, retrieved studies were then screened and data extracted by two independent reviewers.

Out of 11 225 studies identified by our searches, 71 were included in the review after screening. Compared with low-potency cannabis, our findings suggest that high-potency cannabis is more strongly associated with severe mental health issues, such as cannabis dependence, psychosis and cognitive deficits.

Overall, it was found that high-potency cannabis use (>15% THC) was associated with a great number and magnitude of adverse mental health outcomes. As such, the potency of cannabis products should be measured in future cannabis research that investigates short- and long-term outcomes. Additionally, the potency of cannabis products should be a consideration in any future cannabis regulatory policy discussions.

Increasing survival probabilities among children and young adults with acute lymphoblastic leukemia (ALL) have led to a growing population at risk for long-term neurocognitive sequelae. This study investigated cognitive functioning among individuals treated for ALL under the Nordic Society of Paediatric Haematology and Oncology ALL2008 protocol in Eastern Denmark, including performance across multiple domains and associations with age at diagnosis, sex, time since end of treatment, hematopoietic stem cell transplantation (HSCT), and neurotoxic events during treatment.

Eighty-three survivors of ALL diagnosed before age 25 underwent neurocognitive testing at a median of 7.24 years post-treatment (interquartile range: 4.20–8.78). Performance was measured as age-standardized Z scores derived from normative data. Impairment was defined as Z ≤ −1.3 and severe impairment as Z ≤ −2.0. Multiple linear regression was used to investigate associations between cognitive outcomes and clinical risk factors.

Average performance was generally comparable to norms, but at least 38.6% of participants showed severe impairment in one or more domains, and at least 12% in two or more. Younger age at diagnosis was associated with poorer processing speed, executive functions, and non-verbal reasoning, while HSCT was associated with poorer processing speed and non-verbal reasoning.

Although average performance of the participants was generally comparable to norms, a notable proportion exhibited multi-domain, severe cognitive impairment. Associations with age at diagnosis and HSCT indicate potential for risk-stratified cognitive monitoring and targeted interventions.

To provide insights into the motivations, challenges, and preferred methods of contact that influence the recruitment and retention of young adults (YAs) in health research.

We designed, collected, and analyzed two surveys targeting YAs aged 18–39 years through the Amazon MTurk platform, to assess factors influencing recruitment and retention in health studies. The recruitment survey (n = 477) examined initial engagement motivations, while the retention survey (n = 473) explored factors that sustain long-term participation. Descriptive analyses were stratified by age group and sex.

The recruitment survey indicated that 88% of YAs were willing to participate in health studies, with a preference for online formats (78%). Social media, particularly Facebook (53%), was endorsed as the most common platform for discovering research opportunities. Monetary incentives were reported as the top motivator across all age groups, especially for those aged 35–39 years, with gift cards endorsed as the most appealing to participants aged 18–34. Retention survey results indicated that email (100%) was the most preferred method for maintaining engagement, followed by text messages (78.9%) and social media (62.2%). Text messages (65%), regular updates (56%) and sharing of study results (54%) were identified as key factors for maintaining participant engagement.

Our findings identify that YA participation is driven by a mix of altruistic motivations, such as contributing to the community and research, and personal motivations, including personal health benefits and financial incentives, emphasizing the need for strategies that address both aspects of recruitment and retention motivations.

Mental ill-health has a major impact on young people, with pain often co-occurring. We estimated the prevalence and impact of pain in young people with mental ill-health.

Longitudinal data (baseline and three-month follow-up) of 1,107 Australian young people (aged 12–25 years) attending one of five youth mental health services. Multi-level linear mixed models estimated associations between pain characteristics (frequency, intensity, and limitations) and outcomes with false discovery rate (FDR) adjustment. Pain characteristics were baseline-centered to estimate if the baseline score (between-participant effect) and/or change from baseline (within-participant effect) was associated with outcomes.

At baseline, 16% reported serious pain more than 3 days, 51% reported at least moderate pain, and 25% reported pain-related activity limitations in the last week. Between participants, higher serious pain frequency was associated with greater anxiety symptoms (β[95%CI]: 0.90 [0.45, 1.35], FDR-p=0.001), higher pain intensity was associated with greater symptoms of depression (1.50 [0.71, 2.28], FDR-p=0.001), anxiety (1.22 [0.56, 1.89], FDR-p=0.002), and suicidal ideation (3.47 [0.98, 5.96], FDR-p=0.020), and higher pain limitations were associated with greater depressive symptoms (1.13 [0.63, 1.63], FDR-p<0.001). Within participants, increases in pain intensity were associated with increases in tobacco use risk (1.09 [0.48, 1.70], FDR-p=0.002), and increases in pain limitations were associated with increases in depressive symptoms (0.99 [0.54, 1.43], FDR-p<0.001) and decreases in social and occupational functioning (−1.08 [−1.78, −0.38], FDR-p=0.009).

One-in-two young people seeking support for mental ill-health report pain. Youth mental health services should consider integrating pain management.

Major depressive disorder (MDD) is marked by significant changes to the local synchrony of spontaneous neural activity across various brain regions. However, many methods for assessing this local connectivity use fixed or arbitrary neighborhood sizes, resulting in a decreased capacity to capture smooth changes to the spatial gradient of local correlations. A newly developed method sensitive to classical anatomo-functional boundaries, Iso-Distant Average Correlation (IDAC), was therefore used to examine depression associated alterations to the local functional connectivity of the brain.

One-hundred and forty-seven adolescents and young adults with MDD and 94 healthy controls underwent a resting-state functional magnetic resonance imaging (fMRI) scan. Whole-brain functional connectivity maps of intracortical neural activity within iso-distant local areas (5–10, 15–20, and 25–30 mm) were generated to characterize local fMRI signal similarities.

Across all spatial distances, MDD participants demonstrated greater local functional connectivity of the bilateral posterior hippocampus, retrosplenial cortex, dorsal insula, fusiform gyrus, and supplementary motor area. Local connectivity alterations in short and medium distances (5–10 and 15–20 mm) in the mid insula cortex were additionally associated with expressive suppression use, independent of depressive symptom severity.

Our study identified increased synchrony of the neural activity in several regions commonly implicated in the neurobiology of depression. These effects were relatively consistent across the three distances examined. Longitudinal investigation of this altered local connectivity will clarify whether these differences are also found in other age groups and if this relationship is modified by increased disease chronicity.

To estimate the effect of income change on difficulty accessing food since the COVID-19 pandemic for South African youth and evaluate whether this effect was modified by receiving social grants.

A cross-sectional, online survey was conducted between December 2021 and May 2022. Primary outcome was increased difficulty accessing food since the COVID-19 pandemic. Income change was categorised as ‘Decreased a lot’, ‘Decreased slightly’ and ‘Unchanged or increased’. Multivariable logistic regressions were used, with an interaction term between social grant receipt and income change.

eThekwini district, South Africa.

Youth aged 16–24 years.

Among 1,620 participants, median age was 22 years (IQR 19–24); 861 (53 %) were women; 476 (29 %) reported increased difficulty accessing food; 297 (18 %) reported that income decreased a lot, of whom 149 (50 %) did not receive social grants. Experiencing a large income decrease was highly associated with increased difficulty accessing food during the COVID-19 pandemic (adjusted OR [aOR] 3·63, 95 % CI 2·70, 4·88). The aOR for the effect of a large income decrease on difficulty accessing food, compared to no income change, were 1·49 (95 % CI 0·98, 2·28) among participants receiving social grants, and 6·63 (95 % CI 4·39, 9·99) among participants not receiving social grants.

While social grant support made a great difference in lowering the effect of income decrease on difficulty accessing food, it was insufficient to fully protect youth from those difficulties. In post-pandemic recovery efforts, there is a critical need to support youth through economic empowerment programming and food schemes.

The increased survival rate among individuals with CHD has sparked interest in their transition to adult healthcare. Although there is a general agreement on the importance of transition interventions, the empirical evidence supporting them is insufficient. Therefore, this study aimed to conduct a systematic review and meta-analysis of transition interventions for adult healthcare in adolescents and young adults.

A literature search was conducted for studies comparing the quantitative effects of transition interventions with control groups, published up to March 15, 2023, in major databases (CENTRAL, Embase, PubMed, Web of Science, CINAHL, KISS, and KMbase), major clinical trial registries, academic journal sites related to the topic, and grey literature databases. Ten studies involving a total of 1,297 participants were identified. Transition interventions proved effective in enhancing disease-related knowledge (Hedge’s g = 0.89, 95% CI = 0.29−1.48) and self-management (Hedge’s g = 0.67, 95% CI = 0.38−0.95), as well as reducing loss to follow-up (OR = 0.41, 95% CI = 0.22−0.77). The certainty of evidence for the estimated values of each major outcome was low or very low.

This study supports the implementation of transition interventions by demonstrating that they can improve patients’ disease knowledge and self-management, while also promoting treatment continuity. However, since the available data on transition interventions for adolescents and young adults with CHD remain limited, the widespread adoption of structured transition interventions in the future may alter the conclusions of this study.

URL: https://www.crd.york.ac.uk/PROSPERO. Unique identifier: CRD42023399026.

Describe how dietary intake patterns of US young adults align with the EAT-Lancet Planetary Health Diet (PHD) sustainable diet goals and identify personal, behavioural, and socio-environmental correlates of sustainable intake.

Data on past-year dietary intake were captured using a FFQ. The PHD was applied to specific food groups, and a total PHD score was calculated. Linear regression models were used to identify associations between personal, behavioural and socio-environmental factors and PHD scores.

This cross-sectional analysis uses data from the second wave of EAT 2010–2018 (Eating and Activity over Time), a population-based longitudinal study recruited in Minnesota.

Ethnically/racially diverse group of participants (n 1308) with a mean age of 22·1 (sd 2·0) years.

The mean PHD score was 4·1 (sd 1·4) on a scale of 0–14, with 14 representing the most sustainable. On average, participants consumed fewer whole grains, fish, legumes, soya, and nuts than ideal for a sustainable diet, and an excess of eggs, added sugar, and meat. The PHD score was higher for participants with higher socio-economic status (SES) and greater educational attainment. Higher home availability of healthy food (β = 0·24, P < 0·001) and less frequent fast-food consumption (β = –0·26, P < 0·001) were the strongest correlates of PHD scores.

Results suggest that a high percentage of participants may not be achieving the sustainable diet goals defined by the PHD. Reductions in meat consumption and increases in plant-based foods are necessary to increase the sustainability of US young adults’ diets.

Youth suicide rates have increased markedly in some countries. This study aimed to estimate the population-attributable risk of psychiatric disorders associated with suicide among Taiwanese youth aged 10–24 years.

Data were obtained from the National Death Registry and National Health Insurance (NHI) claims database between 2007 and 2019. Youth who died by suicide were included, and comparisons, 1:10 matched by age and sex, were randomly selected from the Registry for NHI beneficiaries. We used multivariable logistic regression to estimate suicide odds ratios for psychiatric disorders. The population-attributable fractions (PAF) were calculated for each psychiatric disorder.

A total of 2345 youth suicide and 23 450 comparisons were included. Overall, 44.8% of suicides had a psychiatric disorder, while only 7.9% of the comparisons had a psychiatric disorder. The combined PAF for all psychiatric disorders was 55.9%. The top three psychiatric conditions of the largest PAFs were major depressive disorder, dysthymia, and sleep disorder. In the analysis stratified by sex, the combined PAF was 45.5% for males and 69.2% for females. The PAF among young adults aged 20–24 years (57.0%) was higher than among adolescents aged 10–19 years (48.0%).

Our findings of high PAF from major depressive disorder, dysthymia, and sleep disorder to youth suicides suggest that youth suicide prevention that focuses on detecting and treating mental illness may usefully target these disorders.