Lack of evidence on mental health and well-being impacts of individual-level interventions for vulnerable adolescents: systematic mapping review.

•Adolescence is a critical life course period for interventions to reduce/prevent current and future distress and dysfunction.•Alongside population health approaches, targeted approaches to high-risk groups are valuable to address health inequalities.•We found insufficient evidence of individual-level interventions to improve mental health/wellbeing of vulnerable groups.•Despite policy, our review suggests a lack of evaluation of mental health/wellbeing outcomes of such targeted interventions.