Mental health problems have long-lasting impacts and often begin in adolescence, yet young people face multiple barriers to accessing care and support, including a fragmented system, limited awareness of services and stigma. Afloat was developed to guide users to suitable support.

This study aimed to (a) co-develop a mobile app to support young people’s access to mental healthcare and support; and (b) evaluate its acceptability, potential impact on service use, mental health outcomes and economic implications.

Afloat was co-developed with young people to provide information on available support, and included personal stories from peers and links to care resources. A pilot evaluation involved 105 participants aged 16–25 years from London, UK. Participants completed surveys at baseline and 3 months to assess changes in mental health, service use, stigma and self-identification of mental health issues. App usage was monitored through analytics. A budget-impact analysis estimated financial implications of Afloat implementation.

Participants reported high acceptability and satisfaction. After 3 months, there was an increase in the likelihood of help-seeking and a reduction in mental health symptoms. The increase in actual service use was significant only among those with mild-to-moderate symptoms. Budget-impact analysis indicated potentially increased costs from additional service use.

Afloat shows preliminary promise as a tool associated with increased help-seeking and improved mental health. Long-term benefits of timely intervention may offset short-term costs from increased service use, although this requires formal evaluation. Further research is required to assess long-term outcomes and economic implications.

Sub-threshold depression (SD) affects around 11% of adolescents and can be as impairing as conditions reaching the full diagnostic criteria of Major Depressive Disorder (MDD). However, limited research has been conducted on how affective disturbances manifest in SD during adolescence, a period of affective vulnerability. We compared three groups of adolescents along the spectrum of depression on their positive affective (PA) and negative affective (NA) levels and dynamics, including variability, inertia, and reactivity to event-related stress and pleasure in daily life.

One hundred and ninety eight adolescents (age 12–18), grouped by psychiatric diagnosis (MDD = 66; SD = 35; healthy controls, HC = 88), completed a 14-day experience sampling on their smartphone, clinical ratings, and questionnaires. They were recruited from multiple sources, including an epidemiologic study and specialist clinics.

The level of NA was the highest in MDD, followed by SD and HC; vice versa for PA. MDD and SD displayed greater NA variability than HC. NA inertia was greater in MDD than SD and HC. NA reactivity (to event-related pleasure and stress) and PA reactivity (to event-related pleasure) were greater in MDD and SD than HC. SD showed greater PA reactivity to event-related stress than MDD.

Adolescents with SD were as reactive and expansive in their NA experience as the MDD group, but they did not stay in that negative state for as long. The SD group was more reactive than HC to event-related pleasure and stress, suggesting heightened sensitivity. Clinical implications of emotional sensitivity and flexibility on early intervention for depression are discussed.

Parents of adolescents facing suicidality play a crucial protective role, but often feel overwhelmed. The Partners in Parenting Plus – Suicide Prevention (PiP-SP+) programme is a co-designed, coach-supported, online parenting programme aimed to empower parents within their carer role to manage their adolescent’s suicide risk.

To evaluate PiP-SP+’s acceptability, feasibility, validity and short-term effects.

Fifteen parents of adolescents aged 12–18 years, concerned about their adolescent’s suicidality, participated in an open-label, non-randomised uncontrolled trial. Parents (n = 11) completed semi-structured interviews, exploring the programme’s acceptability, feasibility and validity. Thirteen parents completed quantitative assessments of parental self-efficacy to respond to adolescent suicidality and non-suicidal self-injury, protective parenting behaviours, carer burden, parental distress, mental health support quality, family functioning, and adolescent anxiety and depressive symptoms at baseline and 120 days post baseline. Finally, nine adolescents of the participating parents self-reported anxiety symptoms, depressive symptoms and perceptions of parental support at baseline and 120 days post baseline.

PiP-SP+ was an acceptable, feasible and valid intervention for parents. Significant baseline-to-post-intervention improvements were observed in parents’ self-efficacy to respond to adolescent suicidality and non-suicidal self-injury, protective parenting behaviours, carer burden, parental distress and mental health support quality. No significant differences were reported in family functioning. Adolescents perceived increased parental support; both parents and adolescents reported reductions in adolescent anxiety symptoms. Although parents reported a significant decrease in adolescent depressive symptoms, adolescents did not.

Findings support the value of undertaking an appropriately powered, randomised controlled trial to confirm these pilot findings.

Youth in low- and middle-income countries (LMICs) bear a disproportionate burden of mental health conditions, alongside low health-seeking behaviours and limited access to services. These gaps underscore the need for accessible strategies such as youth peer-based mental health programmes and supports (Y-PBMHPS).

To examine whether Y-PBMHPS can help address the mental health needs of LMIC youth.

We conducted a rapid review of peer-reviewed literature, searching Medline, PsycINFO, CINAHL, CAB Global Health, Science Citation Index and Social Sciences Citation Index for studies of Y-PBMHPS in LMICs published in English between 1 January 2002 and 19 September 2025. Two review authors performed title/abstract screening and full-text review. Study quality was assessed by one review author using Joanna Briggs Institute critical appraisal tools. The primary outcome was change in mental health status, expressed in standardised difference units.

Of 6105 unique records identified, 329 studies were reviewed in full and 34 were included. All studies were conducted in Asia or Africa; 17 were quantitative studies (including randomised controlled trials), 9 were qualitative studies and 8 used quantitative designs with qualitative findings. Y-PBMHPS included counselling, psychotherapy, psychoeducation and self-help groups, with peers acting as leaders, facilitators, educators or service providers. Quantitative studies most frequently assessed anxiety and depression, reporting negligible to moderate effects. Qualitative findings indicated good fidelity, adherence and acceptability, alongside some feasibility challenges.

Y-PBMHPS can broaden youth mental health support and services in LMICs. Clearer guidelines on peer selection, training and supervision and further research in other LMICs, including cost-effectiveness evaluations, would strengthen the evidence base.

C-reactive protein (CRP) has been studied in relation to bipolar disorder (BD) and suicidality independently. Although suicide risk is elevated in youth with BD, little is known about the association of CRP with suicidality in this population.

211 youth participated, including 23 BD with lifetime suicide attempts (BDSA), 45 BD with lifetime non-suicidal self-injury (NSSI; BDNSSI), 39 BD without lifetime suicide attempt or NSSI (BDNo-SA/NSSI), and 104 healthy controls (HC). Suicide attempts and NSSI were assessed systematically. Fasting blood samples yielded CRP levels. Primary analyses controlled for age, sex, and body mass index percentile.

CRP levels differed across groups (F3,204 = 3.40, p = 0.02, ηp2 = 0.05). In post hoc analyses, CRP levels were significantly higher among BDSA (3.44 ± 6.42 mg/L) vs HC (0.81 ± 0.90 mg/L; p < 0.01) and BDNo-SA/NSSI (1.42 ± 3.31 mg/L; p = 0.01) groups; however, no difference was seen with the BDNSSI group (1.83 ± 2.22 mg/L; p = 0.12). Between-group differences in CRP levels persisted in independent sensitivity analyses controlling for current mood symptoms, lifetime mania score, lifetime smoking, and medications, but not with lifetime depression score.

Suicide attempts among youth with BD are associated with elevated CRP. Given accessibility of CRP testing, the present findings have potential clinical implications. Larger, longitudinal studies with repeated measures are needed to examine time-varying associations between CRP and suicide risk among youth with BD.

Interpersonal violence is a known risk factor for suicide, but its impact across racial and ethnic groups, particularly among Black and Indigenous youth, remains underexplored.

We conducted a nationwide longitudinal study involving 9,788,264 individuals aged 10–29 years who were enrolled in the 100 Million Brazilian Cohort and linked to Notifiable Diseases Information System (SINAN), National Hospital Information System (SIH) and Mortality Information System (SIM) (2011–2018). Exposure was any recorded interpersonal violence; the outcome was suicide (ICD-10 X60–X84). Cox models adjusted for demographic, socioeconomic, household factors, prior psychiatric hospitalization, and self-harm. Analyses were stratified by race.

During follow-up, 92,287 (0·94%) individuals had a record of interpersonal violence, and 1,657 suicides were identified. Exposure to violence was associated with a higher risk of suicide (HR 2·92; 95% CI 2·06–4·15). Associations were strongest among Indigenous youth (HR 10.61; 95% CI 4.34–25.94), followed by Black youth (HR 3.14; 95% CI 1.92–5.14). No significant association was observed among White youth.

Interpersonal violence is a major risk factor for youth suicide in Brazil, disproportionately affecting Indigenous and Black populations. Addressing systemic racism and structural inequalities is essential for equitable suicide prevention.