The effectiveness of a low-intensity problem-solving intervention for common adolescent mental health problems in New Delhi, India: protocol for a school-based, individually randomized controlled treatment trial with an embedded stepped-wedge cluster randomized controlled recruitment trial

Background Conduct, anxiety and depressive disorders account for over 75% of the adolescent mental health burden globally. The current protocol will test a low-intensity problem-solving intervention for school-going adolescents with common mental health problems in India. The protocol also tests the effects of a classroom-based sensitization intervention on the demand for counselling services in an embedded recruitment trial. Methods We will conduct a two-arm individually randomized controlled trial in six Government-run secondary schools in New Delhi. The targeted sample is 240 adolescents in grades 9-12 with persistent, elevated mental health symptoms and associated impact. Participants will receive either a brief problem-solving intervention delivered over 3 weeks by lay counsellors (intervention), or enhanced usual care comprised of problem-solving booklets (control). Self-reported adolescent mental health symptoms and idiographic problems will be assessed at 6 weeks (co-primary outcomes) and again at 12 weeks post-randomization. In addition, adolescent-reported impact of mental health di�culties, perceived stress, mental wellbeing and clinical remission, as well as parent-reported adolescent mental health symptoms and impact scores, will be assessed at 6 and 12 weeks post-randomization. We will also complete a parallel process evaluation, including estimations of the costs of delivering the interventions. An embedded recruitment trial will apply a stepped-wedge, cluster (class)- randomized controlled design in 70 classes across the six schools. This will evaluate the added impact of a classroom-based sensitization intervention over school-level recruitment sensitization activities on the primary outcome of referral rate into the host trial (i.e. the proportion of adolescents referred as a function of the total sampling frame in each condition of the embedded recruitment trial). Other outcomes will be the proportion of referrals eligible to participate in the host trial, proportion of self-generated referrals, and severity and pattern of symptoms among referred adolescents in each condition. Power calculations were undertaken separately for each trial. A detailed statistical analysis plan will be developed separately for each trial prior to unblinding. Discussion Both trials were initiated on 20 August 2018. A single research protocol for both trials offers a resource-ecient methodology for testing the effectiveness of linked procedures to enhance uptake and outcomes of a school-based psychological intervention for common adolescent mental health problems.


Background
Adolescence is a critical period for the prevention and treatment of mental health problems.Around 10% of adolescents experience a mental disorder (1) and about half of all mental disorders have their onset by the mid-teens, rising to three-quarters by the mid-20s (2).Effective early intervention is therefore vital to mitigate the substantial personal, family and societal costs of mental disorders (3).Low-and middleincome countries (LMICs) are home to 90% of the world's 1.3 billion adolescents, but there is a severe shortage of mental health services targeting this age group in most LMICs(4).This includes India, which is home to one-fth of the global population of adolescents (4).Resource constraints are compounded by low demand for mental health care and the scarcity of context-speci c evidence on the effectiveness of interventions (5).Although there is a robust body of research testifying to the treatability of adolescent mental disorders, mainly through psychological interventions such as cognitive behavioural therapy (CBT), the bulk of such evidence originates from high-income countries (6).Generalisability of the existing evidence base to LMICs is further restricted by the widespread use of specialist providers in intervention trials, with supervision often provided directly by program developers (7).
Transdiagnostic approaches have been advocated as a means of providing more scalable psychological interventions (8), with emerging evidence (mainly from adult populations) supporting their use in LMICs (9,10).Transdiagnostic interventions recognise the considerable overlap that exists in the constituent elements of disorder-speci c protocols and the abundance of shared risk and protective factors for psychopathology in general (11).The available data suggest that transdiagnostic interventions may be comparable in effectiveness to their disorder-speci c counterparts, although head-to-head comparisons are scarce (12).There are also indications that transdiagnostic protocols may confer advantages in terms of improved e ciencies afforded by the parsimonious use of a single intervention framework for multiple problems (13), as well as meeting an expressed need among practitioners for therapies that are designed to t 'real-world' settings where psychosocial complexity and comorbidity are commonplace (14).
The PRIDE (PRemIum for aDolEscents) research program involves linked studies in India with the goal to design and evaluate a scalable transdiagnostic intervention model that addresses common mental health problems (i.e.anxiety, depression and conduct di culties) in school-going adolescents.The public health importance of adolescent mental health has been recognised in the National Adolescent Health Program (the Rashtriya Kishor Swasthya Karyakram) (15).PRIDE was initiated in response to these national and global priorities, and challenges, for improving the quality and coverage of adolescent mental health interventions.The process of aligning the global evidence base on youth psychotherapies with local evidence followed recommendations from an earlier research program (PREMIUM) on psychological intervention development in low-resource settings, which led to the design and demonstration of the clinical effectiveness of two brief psychological treatments for adult mental health problems (16)(17)(18).
Our formative and pilot studies have led to the design of a stepped care architecture involving two interventions of incremental intensity (19)(20)(21)(22).The current trial protocol focuses on the rst step: a lowintensity intervention designed for delivery by non-specialist school counsellors.It focuses on helping the young person to learn and apply problem-solving skills in their daily lives.Problem solving is strongly represented in the global literature, where it is among the most commonly used practice elements in evidence-based mental health programs for children and adolescents (23).It has been applied successfully as the main element in other low-intensity psychological interventions in LMICs (24)(25)(26).The emphasis on problem solving also re ects the primacy of psychosocial factors in adolescents' narratives around explanatory models of distress and help-seeking (21).Our provisional theory of change for the intervention draws on evidence-based principles of stress and coping (27), such that the impact of an ecological stressor is assumed to be mediated by appraisals of the stressor and of the repertoire of available coping resources.Our problem-solving intervention can be considered transdiagnostic in the sense that a single procedure is assumed to have generalized bene ts for a diversity of clinical presentations.Non-responders to this rst-line intervention will be offered a more intensive and dynamic transdiagnostic treatment incorporating additional cognitive and behavioural procedures.The effectiveness of the second step will be evaluated in a separate randomized trial for which participants will be recruited from a different school cohort.
As well as shaping the design of the two intervention steps, formative and pilot work suggested a need for awareness generation around the topics of mental health and psychological help-seeking.We therefore developed a sensitization plan to address factors such as low mental health literacy and con dentiality concerns, which might otherwise impede the demand for school mental health services and the appropriateness of referrals.In so doing, we noted the lack of consistent evidence for the effects of school-based sensitization interventions.Existing approaches have varied considerably in their design and intensity (28)(29)(30) and their ability to increase demand from adolescents for mental health care has yet to be established (31,32).We therefore identi ed an opportunity to test an additional component of the PRIDE intervention architecture -a classroom sensitization session led by school counsellors -by embedding a recruitment trial within a host intervention trial (33).Where applicable, the distinctive features of the two trials are presented sequentially, structured according to the Standard Protocol Items: Recommendations for Interventional Trials (SPIRIT) guidelines (34).Shared features of the two trials (e.g.data management) are presented under uni ed headings.

Objectives and hypotheses
Embedded recruitment trial.The primary objective of this stepped-wedge, cluster randomized controlled trial is to evaluate the impact of a classroom sensitization session (intervention condition), over and above school-level sensitization activities (control condition), on the rate of referred adolescents (i.e. the proportion of adolescents referred as a function of the total sampling frame in each condition) into the host trial.The primary hypothesis is that the classroom-level sensitization intervention will be associated with a higher referral rate into the host trial, compared with referrals arising from school-level sensitization activities in isolation.The secondary hypotheses are that, compared with the control condition, the intervention condition will be associated with a greater proportion of referred students who meet eligibility criteria for inclusion in the host trial (Table 1) and a greater proportion of students who self-refer.We will also explore whether there are any differences between conditions in terms of the severity of total symptoms and symptom subtypes presented by referred adolescents.
Host trial.The primary objective of this two-armed, parallel-design, individually randomized controlled trial is to evaluate the effectiveness of a low-intensity, problem-solving intervention (intervention arm) in reducing adolescent-reported mental health symptoms and idiographic problems at 6 weeks postrandomization, compared with enhanced usual care (control arm), for adolescents with common mental health problems.The primary hypothesis is that the problem-solving intervention will be superior to the control arm in reducing the severity of adolescent-reported mental health symptoms and idiographic problems at 6 weeks post-randomization.

The secondary objectives are:
To evaluate the effectiveness of the intervention on adolescent-reported distress/functional impairment, perceived stress, mental wellbeing and clinical remission To explore whether a theoretically-informed a priori factor (perceived stress at 6 weeks) mediates the effects of the intervention on symptoms of mental health di culties and idiographic problems at 12 weeks To explore the effectiveness of the intervention on caregiver-reported adolescent mental health symptoms, associated distress/functional impairment and adolescent-reported prosocial behavior To evaluate intervention delivery processes in order to assist in the interpretation of the trial results and to inform potential implementation of the PRIDE interventions on a wider scale To estimate the costs and cost-effectiveness of implementing the PRIDE interventions

Methods
Methods are described according to SPIRIT guidelines (34).Completed SPIRIT checklists for the two trials are provided as Additional Files 1 and 2.

Study setting
The two trials will be conducted in six Government-run secondary schools in New Delhi, India.The schools were purposively selected in consultation with the Department of Education, Government of New Delhi, to focus on relatively under-served, low-income communities.Of the six schools, three are boys' schools, two are girls' schools and one is co-educational.Each school contains grades 6-12 of which grades 9-12 will be the focus of this research.As of August 2018, there were 172 classes in grades 9-12 with a total student population of 8448 (ranging from 1050 to 1632 per school; mean =1408; SD=225), including 4694 (56%) boys and 3754 (44%) girls.

Participants
Figures 1 and 2 summarize the participant timeline and ow for the embedded recruitment trial as per CONSORT guidelines for reporting stepped-wedge cluster randomized controlled trials (35).Figure 3 presents the CONSORT diagram for the host trial (36).
Embedded recruitment trial.Seventy classes will participate in the embedded recruitment trial.These classes will be selected at random using computer-generated random numbers, strati ed by school and grade, drawing from a pool of 118 eligible classes (excluding 54 classes that had received sensitization during earlier pilot work in these schools).The participating 70 classes will be randomized to receive the control and intervention conditions across two sequences as shown in Figure 1.A small block size of 2 will be used to allocate the 70 classes across the two sequences in order to ensure balance, as the number of classes within each grade from the individual schools is relatively small.In the rare instance that a selected class has been dissolved or merged with another class, the next class in the random list will be included to replace the unavailable class.Each sequence will be implemented over three consecutive 4-week intervals (excluding holidays and exam breaks).Thus, each class will switch over from the control to the intervention condition at 4-week intervals, over two steps (Figure 1).Schedules for sensitization in the allocated classes will be shared with the schools in advance to ensure access.Host trial.Referrals to the host trial will be generated through a combination of self-referrals, teacher referrals, and referrals made by friends, siblings and/or parents.These referrals will be drawn from the 70 classes sampled in the embedded recruitment trial, with additional participants recruited from the remaining 102 classes as needed.The precise schedule of recruitment activities in the latter classes will be calibrated according to referral patterns and caseload capacity for intervention providers in the various schools.When initiating a self-referral, students will have the option to either approach a counsellor directly or else post a completed referral form/written note in a secure drop-box.The school counsellor will also serve as a central point of contact for other potential referrers, and will offer referral forms on request.All referred adolescents will be followed up by a researcher and screened for eligibility to participate in the host trial (Table 1).

<<Table 1 here>>
Consenting participants (see section on consent procedures below) will be enrolled by researchers and randomized to the intervention or the control arm after baseline outcome assessments are completed.Participants who are randomized to the intervention arm will be escorted by a researcher to meet the counsellor in an adjacent room/cubicle, ensuring e cient and discrete handover.The randomization list will be developed by an independent statistician (HW), applying strati cation by school (and gender for the co-educational school) using randomly sized blocks of four or six.The randomization code will be concealed using sequentially numbered opaque sealed envelopes to maximize allocation concealment (37).Errors in randomization will be recorded and reported.

Sample size and power calculations
Embedded recruitment trial.We based our power calculation on a within-period comparison (38) for a stepped wedge design using Stata package "clustersampsi".Based on pilot data, we anticipated referral rates of 5% and 15% on the control and intervention conditions respectively, with an intra-cluster correlation coe cient (ICC) of 0.124.Using these parameters, a sample size of 70 classes (average class size of 50 students) will have 92% power to detect a difference of 10 percentage points (treating the outcome as a binomial variable), at a signi cance level of 0.05.Host trial.Sample size estimations were produced for two co-primary outcomes: severity of mental health symptoms (SDQ Total Di culties score) and idiographic problems (YTP score).We based the estimations on two data sources.First, we obtained uncontrolled effect sizes (ES=difference in means/SD) for both co-primary outcomes from a group of 52 adolescents who received the problemsolving intervention during pilot work in the six secondary schools in New Delhi.Among these students, all of whom met the same baseline eligibility criteria as intended for the current trial, the mean SDQ Total Di culties scores changed from 23.4 (SD 3.4) at baseline to 16.1 (SD 5.9) at the end of the intervention (ES=1.4).The mean YTP scores for the same group changed from 5.6 (SD 2.0) at baseline to 2.9 (SD 2.6) at the end of the intervention (ES=0.9).Second, we obtained a paired effect size on the SDQ Total Di culties score from another cohort of 47 adolescents participating in a later phase of piloting, including 29 students who received the problem-solving intervention and 18 waitlisted controls (ES=1.0).YTP data were unavailable for this second cohort.Effect sizes in trials are often smaller than in pilots so we conservatively hypothesized that our intervention would be associated with an ES=0.5 on both the coprimary outcomes with 90% power.We assumed a 1:1 allocation ratio of individual participants within each of the six schools, loss to follow up of 15% over 6 weeks (based on piloting), and a Bonferroni correction to adjust for multiple primary outcomes.Based on these assumptions, we determined that N=240 participants would be required.This sample size also provides 80% power to detect an ES of 0.44.

Interventions Embedded recruitment trial
Intervention condition.This will comprise a one-off 30-minute classroom session that is intended to improve understanding about signs and symptoms of mental health problems, raise awareness about the school counselling service, and generate demand for the service.The session will be delivered for individual classes (approximately 50 students per class) by a counsellor (drawn from the same group responsible for the problem-solving intervention in the host trial) with assistance from a researcher who has additional responsibilities for processing referrals and conducting eligibility assessments.The classroom session will start with a short animated video (link to video) which provides age-appropriate information about types, causes, impacts and ways of coping with common mental health problems.The video is followed by a guided group discussion, structured around a standardized script that builds on the topics covered in the video.In case of technical di culties that may prevent the video from being shown, the counsellor will use a ipchart based on printed images from the video.At the end of the session, students will be handed a self-referral form which includes normalizing information and question-based prompts to assist with self-identi cation of mental health problems.Interested students can approach the facilitators immediately after the session with self-referral forms, or else deposit the forms discreetly in a secure drop-box located outside or near to the counsellor's usual room.
The counsellors and researchers delivering the classroom sensitization sessions will be provided with a structured manual and complete a one-day o ce-based training.Training will be conducted by master's level psychologists (who will also serve as supervisors) and comprise lectures, demonstrations and roleplays.The training will be followed by a period of supervised eld practice, when the counsellors and researchers will be required to complete at least two classroom sessions independently under direct observation from supervisors.Fidelity of intervention delivery will be assessed on a checklist of observable procedures which have been distilled from the intervention manual.Each procedure will be rated on a three-point Likert scale (not completed, partially completed, fully completed).A 'refresher' training session will also be conducted before the trial begins.
Control condition.This will comprise whole-school sensitization activities.The supervisor will meet the principal of each school individually to inform them about planned counselling and research activities and to seek their cooperation for the same.This meeting will also provide structured information about common mental health problems faced by adolescents, and address any concerns related to planned procedures and resource demands.Teachers will be invited to participate in separate group sensitization meetings (up to 30 teachers at a time).A standardized script will mirror the topics covered in the meetings with the school principals, but with additional emphasis placed on referral procedures for the host trial.Up to three meetings will be held in each school to maximize coverage of teaching staff.The meeting will be conducted by the same counsellor and researcher pairing responsible for delivering the classroom intervention.Posters will be placed in highly visible locations such as noticeboards or common corridors, in addition to signage on the drop-box, which will remind students (and teachers) of the counselling service.

Host trial
Intervention arm.A problem-solving intervention will be delivered to individual students across 4-5 faceto-face sessions spread over three weeks.Each session will last for up to 30 minutes (aligned with the usual duration of school periods) and will be delivered in the local language (Hindi).The sessions will be conducted on school premises in private rooms or, where private rooms are not available, behind screens and curtains in a suitable location (e.g. the school library).Such contingencies to address space limitations were piloted in earlier work and deemed to be feasible and acceptable in the local context, enabling a temporary counselling space in which students are not on direct view.Session 1 will focus on fostering engagement, understanding the participant's di culties, and introducing the structure and process of the treatment.Over the next three sessions, the participant will be helped to learn and apply a structured problem-solving strategy involving three steps (following the acronym "POD"): (1) identify and prioritize distressing/impairing problems ("Problem Identi cation"); (2) generate and select coping options for modifying the identi ed problem directly (problem-focused strategies) and/or the associated stress response (emotion-focused strategies) ("Option Generation"); and (3) implement and evaluate the outcome of this strategy ("Do it").The intervention may be concluded after four sessions or else extended to a fth session, depending on the adolescent's preferences and logistical barriers to intervention completion such as exam breaks and holidays.The concluding session will focus on consolidating learning and generalizing problem-solving skills across different contexts.With permission, all sessions will be audio-recorded for o ce-based quality and delity assessments.Adolescents will be encouraged to practice problem-solving skills between the sessions, aided by a set of three "POD booklets" which explain problem solving using illustrated vignettes and suggest corresponding between-session practice exercises.The booklets (each corresponding to one of the steps of problem solving) will be distributed sequentially over the rst three intervention sessions.In the concluding session, the adolescent will be additionally handed a full-color POD poster that summarizes the three steps of problem-solving.
Each school will have one or two counsellors, depending on demand.The counsellors will be Hindispeaking college graduates aged 18 years or above, with no formal training or quali cations related to psychotherapy or mental health.They will be recruited through online job portals commonly used in the NGO/public sector in India.Selection will be based on reasoning capacity (assessed by written test) and interpersonal skills (assessed by structured role-plays and interview).Selected candidates will receive an intervention manual and complete one week of classroom-based training involving a combination of lectures, demonstrations and role-plays.This will be followed by a minimum 6-week period of eld training in which counsellors will carry out casework (with at least four cases) under the supervision of psychologists.Trainees' performance will be evaluated using structured role-plays at the end of classroom-based training, as well as supervisors' ratings of audio-recorded intervention sessions.
Counsellors will participate in weekly peer group supervision meetings, based on an approach tested in the PREMIUM trials, where it was found to be an acceptable, effective and scalable supervision model for lay counsellors in low-resource settings (39).Each 2-hour meeting will be facilitated by one of the counsellors in rotation and overseen by a supervisor.Counsellors will review and discuss one or two audio-recorded sessions in each meeting.Audio-recordings will be rated by all group members using a therapy quality rating scale that incorporates elements from two established scales (40,41) and assesses skills speci c to problem-solving as well as non-speci c therapeutic skills (e.g.empathic understanding).
Recurrent skills de cits noted by supervisors will be addressed through supplementary training workshops held on a monthly basis.The supervision schedule will ensure a representative selection of audio-recorded sessions, with the intention that all counsellors should receive equal opportunities to discuss their cases.In addition, supervisors will undertake weekly telephone calls (lasting 20-30 minutes) with each counsellor in order to monitor the progress of their caseload, and identify and manage risks.
The counsellors will be able to initiate ad hoc calls if urgent consultation is needed on any case.Control arm.There are no mental health services in the participating schools.A standardized control arm was devised accordingly, keeping in mind the requirement to offer a pragmatic, resource-e cient mode of support with minimal risk of contamination between trial arms.In terms of contamination, a recent scoping review of complex intervention trials in mental health (42) found that the principal processes leading to contamination were the same clinicians treating participants across conditions, and communication between clinicians/participants.Moreover, the review recommended that methods other than cluster randomization should be considered to minimize contamination, given the lack of evidence for a link between the level of randomization and intervention effect size.
Participants allocated to the control arm will therefore receive the same printed problem-solving materials used in the intervention arm but without any counsellor contact.Immediately following random allocation to this condition, a researcher (rather than a counsellor) will provide a set of POD booklets and explain their purpose and contents using a standardized script.Students will be encouraged to read through the booklets in sequence, and complete the speci ed practice exercises.No further guidance will be provided.In this way, all trial participants will receive the POD booklets, thereby eliminating the likeliest source of contamination.The counselling process itself is less likely to spill-over as this will be delivered in a one-to-one individual format, and our formative and pilot work showed that students emphasized con dentiality (mentioned earlier) such that disclosure of counselling experiences should be minimized.

Screening and outcome measures
Embedded recruitment trial.The primary outcome (referral rate based on the proportion of referred adolescents as a function of the total sampling frame in each condition) will be collated from referral logs maintained by researchers in each school.Referral data will be aggregated over each 4-week calendar period.Students deemed ineligible for participation in the host trial will be allowed to re-refer themselves after a gap of 4 weeks, offering a suitable time period to re-assess mental health status in line with the host trial's inclusion criterion about symptom chronicity (see Table 1).Secondary outcomes pertaining to the eligibility and clinical characteristics of students referred to the host trial will be derived from screening data on the Strengths and Di culties Questionnaire (SDQ) (43,44) (see below).
Host trial.All screening and outcome assessments will be undertaken using standardized self-report measures that have been translated into Hindi.Clinical eligibility criteria (i.e.severity, chronicity and impacts of mental health symptoms) will be assessed using the adolescent-reported form of the SDQ (including the Impact Supplement).The same screening data will also serve as the baseline SDQ/Impact Supplement outcomes for eligible participants who are subsequently enrolled in the trial; baseline assessments for other outcome measures will be completed as soon as possible after completing consent procedures (ideally within 2 working days).The adolescent-reported SDQ/Impact Supplement will be repeated at 6-and 12-weeks post-randomization, along with the parent-reported SDQ/Impact Supplement, and adolescent-reported Youth Top Problems (YTP) (45), Perceived Stress Scale-4 (PSS-4) (46-48) and Short Warwick-Edinburgh Mental Wellbeing Scale (SWEMWBS) (49).These measures are described in Table 2.The SDQ will also serve as the basis for assessing remission at both end-points, de ned as falling below cut-offs for eligibility on both the SDQ Total Di culties score and Impact score.

Process measures
Process data on enrollment, randomization and assessment procedures in both trials will be obtained from researcher-completed record forms.These will be collated to obtain assent/consent rates of adolescents and parents (and reasons for missing assent/consent); randomization rates (and reasons for randomization errors); completion rates of baseline and follow-up outcome assessments (and reasons for non-completion); and time lags between intended and completed assessments (and reasons for deviating from targets).In addition, motivations for help-seeking and expectancies for the school counselling program will be explored at the time of eligibility assessment through a brief qualitative interview with a sub-sample of referred students.Similarly, motivations and expectancies of ineligible students will also be explored; assent/consent to use the interview data in the research will be obtained as part of the consent process for the embedded recruitment trial.Intervention processes will be assessed using additional data sources.In the embedded recruitment trial, counsellor-completed record forms will provide data on key participation indicators including attendance rates and duration for all teacher meetings and classroom sensitization sessions, in addition to the numbers of posters and drop-boxes installed in the schools.
In the intervention arm of the host trial, counsellor-completed session record forms will be used to obtain process data on duration, spacing and frequency of attended sessions (and reasons for non-attendance); and intervention uptake and completion rates (and reasons for pre-intervention and mid-intervention dropout).Participants' adherence to intervention activities and potential engagement challenges will be assessed using checklists within the same record forms, indicating whether or not the student completed practice exercises at home; used the POD booklets at home; brought the POD booklets to the session; and demonstrated understanding of POD booklets and session content.Use of POD booklets will be assessed in each arm of the trial at 6-and 12-week follow-up using a brief adolescent-reported measure that asks about estimated frequency of home use and perceived helpfulness of POD booklets in the preceding 6 weeks.Service satisfaction data will also be obtained from participants in each trial arm at 12 weeks using an 8-item service satisfaction questionnaire with three additional free-text questions (50).Three supplementary questions will elicit open-ended written feedback on the most preferred aspects of the service, potential areas for improvement and recommended changes.
Intervention quality and delity will be assessed in both trials using independent ratings of audiorecorded sessions.For the classroom sensitization intervention, 20% of all recordings will be selected at random and rated by a psychologist who is not directly involved with supervision of the intervention providers.A similar approach will be taken with the problem-solving intervention, for which 10% of all audio-recorded sessions will be rated independently.Reliability of the independent raters will be established initially by comparison with intervention quality and delity ratings from supervisors (see above).

Blinding
Embedded recruitment trial.The researchers who co-facilitate the classroom sensitization sessions will also record referrals and conduct the host trial eligibility assessments.Blinding of the outcome assessors will therefore not be possible.
Host trial.Baseline andoutcome assessments will be conducted by separate teams of researchers.All trial investigators, apart from the data manager (BB), will be blind to allocation status until the trial arms are revealed in the presence of both the Trial Steering Committee (TSC) and Data Safety and Monitoring Committee (DSMC).However, unblinding of individual participants will be undertaken in case of a serious adverse event and requested by the Data Safety and monitoring Committee.

Data collection, management and analysis
Data collection.There will be a seamless ow of adolescents from the embedded recruitment trial to the host trial.The schedules for enrollment, interventions and assessments are summarized in separate SPIRIT diagrams for the embedded recruitment trial (Figure 4) and host trial (Figure 5).A team of schoolbased researchers will process the referrals, undertake eligibility assessments for the host trial (within a target of <=3 working days from the date of referral) and obtain adolescent assent/consent (within the same day if possible).A separate team of community-based researchers will visit parents/guardians (within a target of <=2 working days after con rming an adolescent's eligibility) to obtain consent and complete baseline outcome assessments (within the same day if possible).The school-based research team will complete baseline outcome assessments with adolescents once all consent procedures are completed (within a target of <=2 working days).All assessment procedures should therefore be completed within 7 working days from the date of referral.
The community-based research team (blinded to allocation) will complete follow-up assessments at 6 and 12 weeks post-randomization.Assessments will take place at participants' homes or other convenient locations, within a maximum period of 7 calendar days from the due date.Researchers will make up to four approaches for each scheduled contact.
Process data from researchers' logs and counsellors' session records will be captured on paper forms.All other measures, except for the YTP (which rates idiographic problems and does not readily lend itself to a digital format), will be administered via a tablet computer.Data management.Data will be collected digitally using the customized STAR software program( 51), and will be remotely uploaded as comma-separated values (CSV) les on a secured server.The date and time stamps for original data entry will be included, and an audit trail documenting any subsequent changes will be maintained.All paper-based data will be entered manually in SQL Epi-info forms and linked by participant ID with digitally collected data.Range and consistency checks will be performed at weekly intervals, with all inconsistencies and corrections logged to maintain an audit trail.All data will be anonymized and backed-up on external hard disks on a daily basis.All session audio-recordings will be linked with the participant ID and stored in a separate, secure, password-protected folder.A separate password-protected le linking names and participant IDs and the random allocation code will be maintained securely by the data manager and will not be accessed until the unblinding of the trial.All data will be shared in an encrypted form in password-protected les and through secure electronic transfer, when necessary.Data analysis.Quantitative analysis will be conducted using STATA (version 15).A detailed analysis plan will be agreed with the DSMC before any analysis is undertaken.Findings will be reported as per CONSORT guidelines (36) for the host trial, and the CONSORT extension for reporting of stepped-wedge cluster randomized trials for the embedded recruitment trial (35).
Embedded recruitment trial.The baseline characteristics of the participating 70 classes, including class size and gender composition, will be described and assessed for any systematic differences across the two sequences.The primary outcome will be analyzed using generalized estimating equations (GEE) with robust standard errors.GEE is a recommended method for analysis of stepped-wedge cluster randomized controlled trials, providing population-averaged effects of exposure across trial conditions (52).GEE allows for longitudinal data analysis without resorting to fully speci ed random effect models and can be applied to both continuous and categorical outcomes (53).It provides both parameter estimates and standard errors that are corrected for clustering of data and are consistent despite misspeci cations in the correlation structure.For this trial, the clustering of data will be speci ed at the class level.Analysis of the secondary and exploratory outcomes will also be undertaken using the GEE method.Sensitivity analysis will be conducted using a 'within-period comparison' of data (38) from the second period only.No interim analyses will be undertaken.
Host trial.The trial owchart will include the number of students referred, screened, eligible, randomized and analyzed for the primary outcome at the 6-week endpoints respectively.The number refusing or excluded (with reasons), actively withdrawing, and passively lost to follow-up will be shown by arm.These will be summarized by means (standard deviation), medians (interquartile range), or numbers and proportions as appropriate to relevant subgroups (de ned by age, gender and baseline outcome score).For continuous outcomes, histograms within each arm will be plotted to assess normality and determine whether transformation is required.
The primary analyses will be on an intention-to-treat basis at the 6-week end-point, adjusted for baseline values of the outcome measure; school (as a xed effect in the analysis) to allow for within-school clustering; counsellor variation (as a random effect); variables for which randomization did not achieve reasonable balance between the arms at baseline; and variables associated with missing outcome data (54).Analyses of outcomes will be conducted using linear mixed-effects regression models for continuous outcomes with normally-distributed errors (e.g.SDQ Total Di culties score) and generalized (logistic) mixed-effects regression models for binary outcomes (e.g.remission rate).Intervention effects will be presented as adjusted mean differences and effect sizes (ES), de ned as standardized mean differences.We will use 95% con dence intervals (CIs) for continuous outcomes, and adjusted odds ratios with 95% CIs for binary outcomes.Additionally, intervention effects for students who receive fewer sessions than prescribed will be estimated using the Complier Average Causal Effect structural equation model (55).Repeated-measures analysis will be used to analyse data from the two end-points (6 and 12 weeks).Initial models will include an interaction effect between arm and time to allow for differential effects at these two end-points.This will be retained if there is evidence of effect modi cation by time.No interim analyses of outcomes will be undertaken.
We will explore potential moderators of intervention effects, with respect to a priori de ned modi ers (chronicity of mental health di culties, severity of mental health di culties, YTP type and SDQ caseness pro le).We will t relevant interaction terms and test for heterogeneity of intervention effects in regression models.A mediation analysis will be conducted to examine whether the theoretically-driven a priori factor (perceived stress at 6 weeks) mediates the effects of the intervention on mental health symptoms and idiographic problems at 12 weeks.Process evaluation.We will undertake descriptive statistical analysis of quantitative process data to explore the differential implementation of intervention procedures.In addition, thematic analysis will be used to code and organise qualitative interview data on service expectancies (assessed prior to enrolment in the host trial) and qualitative written feedback on service satisfaction (assessed at 12-week follow-up in the host trial).Findings from the various data sources will be triangulated and used to develop explanatory hypotheses about potential differences in intervention delivery and participation across schools, subgroups of participants and providers.Process evaluation ndings will be used to facilitate interpretation of the main trial results.The trial statisticians may conduct further analyses to test hypotheses generated from integration of the process evaluation and trial outcome data; these will necessarily be post hoc and identi ed as such in any subsequent publications.
Cost-effectiveness analysis.
An economic evaluation will be conducted to estimate the costs and incremental cost-effectiveness of the problem-solving intervention.A combination of top-down and ingredients-based costing approaches will be used to generate cost estimates for the whole package, and for each package component (e.g.counselling sessions and POD booklets), in the intervention and control arms.All costing will be estimated from the providers' perspective (the schools and the implementing partner Sangath); nancial and economic costs will be calculated for all inputs (e.g.materials, training, supervision, staff time, overheads).The cost analysis will assess the costs of setting up and running the interventions; the distribution of costs across different forms of inputs; the unit cost per student/adolescent reached; the cost per additional case remitted; the cost of delivering all activities in intervention schools; and the cost per unit of measure for selected primary and secondary outcomes.We will estimate the incremental cost effectiveness of the intervention relative to the control condition (enhanced usual care).The costeffectiveness measure proposed here will be compared to similar school programs in the region and it will inform program replication, scalability and nancial sustainability.
Results will be plotted on a cost-effectiveness plane and presented as cost-effectiveness acceptability curves to show the probability of the intervention being cost-effective at a range of willingness-to-pay threshold levels.A sensitivity analysis will be conducted to take account of uncertainty and imprecision in the measurements.

Trial governance
Monitoring and governance for both trials will be provided by a Trial Management Group (comprising senior investigators and project staff involved in day-to-day coordination of research activities), TSC (comprising senior investigators and independent subject experts) and DSMC (a fully independent group with relevant clinical and trials expertise).The TMG and TSC will review trial process indicators (e.g.rates of screening, eligibility, consent, outcome assessments, adverse events) fortnightly and quarterly respectively.The independent DSMC will meet at the outset of the two linked trials and again at the time of unblinding the trial results, as well as receiving reports of emergent serious adverse events (as per criteria below).Any trial protocol amendments will be agreed and formulated in conjunction with the TSC and DSMC, and submitted to relevant Institutional Review Boards for approval.

Discussion
This paper describes an integrated protocol that will evaluate the demand for a school counselling program delivering a low-intensity psychological intervention, and the effectiveness of that intervention for school-going adolescents with elevated mental health presentations in New Delhi, India.The interventions used in the host trial and embedded recruitment trial will be provided by lay counsellors, working under the supervision of psychologists, in Government-run secondary schools catering to adolescents from lower socio-economic groups of the city.Concurrent process evaluation and cost estimation will complement the effectiveness ndings, generating important evidence relevant to the scaling up of the interventions.To the best of our knowledge, these two trials have no comparable precedent from any low-resource context, and our ndings have the potential to inform the design of school-based interventions to address adolescent mental health problems on a large-scale in India and other global settings.
An individually randomized design was chosen for the host trial due to the relatively small number of available schools, which ruled out an alternative cluster randomized design.The inherent risk of contamination associated with individual randomization was minimized by the inclusion of an enhanced usual care control arm, in which participants received the same printed materials as provided in the intervention arm.The augmentation of face-to-face counselling in the intervention arm was not expected to pose a signi cant risk of spill-over due to the reluctance of participants to share con dential counselling experiences with peers.Moreover, enhanced usual care was designed in such a way that the same delivery agents would not be involved in treating participants across conditions, ruling out another commonly cited source of contamination (42).
The use of a stepped-wedge cluster randomized design for the embedded recruitment trial was also in uenced by pragmatic considerations.Formative and pilot work showed that classroom-based sensitization activities had the potential to enhance the number of referrals for school-based counselling.A stepped-wedge design -in which classes formed natural clusters in each school -offered the potential to stagger the roll-out of classroom sessions so that school-based counsellors could accommodate the anticipated ow of referrals within their limited caseload capacity.
Despite the use of contextually adapted sensitization activities, some potentially eligible students (and/or their caregivers) may be unwilling to participate.Reasons for non-participation will be systematically recorded and examined in the embedded process evaluation.We will also seek to address the concerns of referred adolescents who are not eligible for inclusion in the host trial despite a felt need for counselling.In anticipation, we have designed hand-outs with advice on self-management of common problems (such as academic di culties).These hand-outs will be distributed to relevant students by the researcher conducing the baseline screening assessments.Another recruitment challenge relates to the academic calendar in the participating schools, which includes frequent breaks for exams, festivals and other holidays.These scheduling disruptions may require temporary halting of recruitment (for example, so  The Total Di culties score at 6 weeks will be our co-primary outcome.

Adolescentreported
Youth Top Problems (YTP) severity score The YTP is a brief, idiographic measure which identi es, prioritizes and rates three main problems as identi ed by respondents (45).Each of the three problems is scored from 0 to 10 according to perceived problem severity (with higher scores indicating greater severity).A mean severity score is calculated by summing individual problem scores and then dividing by the number of nominated problems.The YTP was translated into Hindi for our pilot studies, where it was found to be highly sensitive to change over the course of the problem-solving intervention.The mean YTP score at 6 weeks will be our co-primary outcome.

Adolescentreported
Secondary outcomes over a 12-week period randomizationa SDQ Total di culties score (see above for description of the measure) Adolescentreported YTP (see above for description of the measure) Adolescentreported

SDQ Impact Supplement
The SDQ Impact Supplement measures distress and functional impairment associated with index mental health di culties identi ed on the main SDQ scale (43).One item on overall distress and four items on domain-speci c functional impairment (home life, friendships, classroom learning, leisure activities) are individually scored from 0-2 (with higher scores indicating greater impact), generating a total impact score from 0 to 10.

SDQ internalizing subscale
The internalizing symptom subscale score is calculated by adding the score of the peer relationship and emotional problem subscales.The score ranges from 0-20.

SDQ externalizing subscale
The externalizing symptom subscale score is calculated by adding the score of the conduct and hyperactivity/inattention problem subscales.The score ranges from 0-20.

Adolescentreported
Perceived Stress Scale-4item version (PSS-4) The PSS-4 measures perceptions of stress, re ecting the degree to which situations are appraised as stressful during the preceding month.This brief measure was chosen because of its feasibility and relevance as a presumed mechanism of change within the problem-solving intervention, consistent with stress-coping theory.
It has been translated into Hindi and used in a number of surveys and as an outcome measure in trials around the world.This brief instrument uses a ve-point scale (0=never, 1=almost never, 2 sometimes, 3=fairly often, 4=very often) to assess how often the respondent has experienced primary appraisals of events as stressful.The total score ranges between 0 and 16, with higher scores indicating a stronger tendency towards stressful appraisals.
A study of secondary students in Hyderabad, India reported high internal consistency (Cronbach's alpha=0.84)and test-retest reliability (0.85) for the longer 14-item form of the PSS (48).

Adolescentreported
Short Warwick-Edinburgh Mental Wellbeing Scale (SWEMWBS) The SWEMWBS is a commonly used measure for mental wellbeing.Wellbeing has been closely linked with social factors such as peer bullying and perception of school connectedness(59); it may therefore be especially amenable to problem solving.The SWEMWBS is a unidimensional scale that comprises seven items scored on a ve-point scale (1=None of the time, 2=Rarely, 3=Some of the time, 4=Often and 5=All of the time) with a total range from 7-35, where higher scores indicate more positive mental wellbeing.
Strong internal consistency has been previously reported in adolescent samples(60).The measure has been used internationally and a Hindi version is available(61).

Adolescentreported
Remission a Remission will be de ned using the 'crossing clinical threshold' method(62) for two clinical criteria (both of which must be met): (i) SDQ Total Di culties score < 19 for boys or < 20 for girls, and (ii) Impact score < 2.    SPIRIT gure for the embedded recruitment trial Figure 5 SPIRIT gure for the host trial

Adolescentreported
57. Srinath S, Kandasamy P, Golhar TS.Epidemiology of child and adolescent mental health disorders in Asia.Curr Opin Psychiatry.2010;23(4):330-6.58.Kanuri N, Newman MG, Ruzek JI, Kuhn E, Manjula M, Jones M, et al.The Feasibility, Acceptability, and E cacy of Delivering Internet-Based Self-Help and Guided Self-Help Interventions for Generalized Anxiety Disorder to Indian University Students: Design of a Randomized Controlled Trial.JMIR research protocols.2015;4(4):e136.59.Patalay P, Fitzsimons E. Correlates of Mental Illness and Wellbeing in Children: Are They the Same?Results From the UK Millennium Cohort Study.Journal of the American Academy of Child & Adolescent Psychiatry.2016;55(9):771-83.60.Clarke A, Friede T, Putz R, Ashdown J, Martin S, Blake A, et al.Warwick-Edinburgh Mental Well-being Scale (WEMWBS): validated for teenage school students in England and Scotland.A mixed methods assessment.BMC public health.2011;11:487.61.Stewart-Brown S. The Warwick-Edinburgh Mental Well-Being Scale (WEMWBS): Performance in Different Cultural and Geographical Groups.In: Keyes CLM, editor.Mental Well-Being: International Contributions to the Study of Positive Mental Health.Dordrecht: Springer Netherlands; 2013.p. 133-50.62. Wolpert M, Görzig A, Deighton J, Fugard AJB, Newman R, Ford T. Comparison of indices of clinically meaningful change in child and adolescent mental health services: difference scores, reliable change, crossing clinical thresholds and 'added value' -an exploration using parent rated scores on the SDQ.Child and Adolescent Mental Health.2015;20(2):94-101.

Figures Figure 1 Figure 2 CONSORT
Figures

Table 1 :
Eligibility criteria for the host trial

Table 2 :
Outcome measures in the host trial Repeated measures analysis of 6-week and 12-week endpoints, adjusting for baseline values