INTRODUCTION
depression, anxiety
A growing body of global evidence attests to the effectiveness of “low‐intensity” psychosocial interventions for common adolescent mental health problems (Catanzano et al., The “PRemIum for aDolEscents” (PRIDE) programme in India has developed a school‐based, transdiagnostic stepped care architecture to address anxiety, depression and conduct problems, which together account for over 75% of the adolescent mental health burden globally (Erskine et al., The problem‐solving component of the PRIDE programme (denoted as “Step 1” within the stepped care architecture) was tested in a randomized controlled trial during 2018–2019. Detailed descriptions of the trial design and main findings have been published elsewhere (Malik et al., The breadth and durability of these outcomes are striking, given the brevity of the problem‐solving intervention formats and the use of a single‐element design. Additionally, mediation analysis indicated that a measure of perceived stress (partly related to the construct of problem orientation) at 6 weeks mediated 15% and 23% of the intervention group effects on measures of psychosocial problem severity and mental health symptoms, respectively, at 12 weeks (Michelson, Malik, Parikh, et al., The complementary use of qualitative methods has the potential to further elucidate mechanisms of change, for example, with respect to the potential relational enhancement provided by peer counsellors and through a detailed exploration of problem‐solving style and how it might be influenced by different intervention materials. There are also implications of such process‐oriented research for the wider field of mental health science, where increasing attention has focused on identifying core “active ingredients” in youth psychotherapies, referring to “those aspects of an intervention that drive clinical effect, are conceptually well defined, and link to specific hypothesised mechanisms of action” (Wolpert et al., The current qualitative study was embedded within the PRIDE Step 1 trial and incorporates interviews that were collected by the trial's research team shortly after the 12‐month outcome assessments. The specific research questions were as follows: (i) What did participants consider to be the main impacts of problem‐solving interventions delivered in low‐intensity counsellor‐led and bibliotherapy formats? (ii) How did specific content and delivery strategies affect outcomes and engagement for participants in the respective intervention formats? (iii) What content and delivery modifications were suggested by participants to optimize effectiveness and scalability of the problem‐solving interventions?