Interpersonal counselling for adolescent depression delivered by youth mental health workers without core professional training: the ICALM feasibility RCT.

Background: As milder cases of adolescent depression do not meet treatment thresholds for specialist mental health services, young people often receive support from non-qualified professionals in third-sector/voluntary agencies. Early psychological interventions to meet growing demand with limited resources are crucial.

Objectives: The study aimed to explore the effectiveness and cost effectiveness of interpersonal counselling for adolescents by (1) assessing the feasibility and acceptability of trial procedures; (2) exploring the delivery of, and differences between, interpersonal counselling for adolescents and treatment as usual; (3) evaluating the extent of contamination of the control arm and if it should be mitigated against in a future trial; and (4) investigating whether the interval estimate of benefit of interpersonal counselling for adolescents over treatment as usual in depression post treatment includes a clinically significant effect.

Design: This was a feasibility randomised controlled trial. Non-qualified professionals from non-specialist mental health services received interpersonal counselling for adolescent training. Participants were randomised to receive either interpersonal counselling for adolescents plus treatment as usual or treatment as usual only. Assessments occurred at baseline and were followed up at weeks 5, 10 and 23. A health economics component was included to inform the design of the economic evaluation in a future study. A process evaluation examined implementation of the intervention across settings, acceptability and contamination. Interviews, observations and focus groups were analysed using thematic analysis. Session recordings were analysed using conversation analysis.

Setting: The trial was conducted in 13 non-speicialist mental health services across Norfolk and Suffolk.

Participants: Help-seeking adolescents aged 12-18 years with mild depression as the primary difficulty were eligible to participate. Comorbid presentations were not an exclusion criterion. Of a target of 60, 16 participants were randomised, and 2 participants withdrew following study suspensions related to COVID-19. Of the remaining 14 participants, 7 received an intervention, with 3 receiving interpersonal counselling for adolescents and 4 receiving treatment as usual. The rest either disengaged, withdrew or were signposted.

Interventions: Participants were randomised to receive either interpersonal counselling for adolescents plus treatment as usual or treatment as usual only.

Main outcome measures: The primary outcome was the Revised Children's Anxiety and Depression Scale, although the proposed study was not designed to assess efficacy. The primary output of the feasibility trial was to design a subsequent full-scale trial.

Results: Feasibility outcomes did not meet the estimated progression criteria. Despite efforts to increase referrals, the 80% recruitment rate was not achieved. Interpersonal counselling for adolescents' attendance rates at 10 weeks were less than the 70% progression criteria estimation, impacting intervention feasibility. Retention was high, with 85.7% of participants reaching 23-week follow-up. The health economic measures appeared to perform well and were completed. Implementation and theoretical fidelity of interpersonal counselling for adolescents were analysed from four participant recordings. Adherence to the principles of interpersonal counselling for adolescents was identified, with 100% satisfactory fidelity and no indication of contamination in the control arm. The two interventions were clinically non-significant due to the study being underpowered.

Limitations: The feasibility of the randomised controlled trial was impacted by COVID-19. Services had to change standard practices, disrupting trial procedures. Challenges were identified when implementing a randomised controlled trial in non-specialist services.

Conclusions: Findings indicate a randomised controlled trial of interpersonal counselling for adolescents in non-specialist services is not feasible, yet the data collection and outcome measures were suitable. COVID-19 challenges, sites' lack of familiarity with research procedures and the research team's unfamiliarity with how different early intervention services operate led to challenges. High staff shortages, turnover and inconsistent training could have been considered. This study demonstrated the difficulties in conducting a randomised controlled trial in this service setting. Further work is needed to improve the feasibility of conducting such trials before they are attempted in future.

Trial registration: This trial is registered as ISRCTN82180413.

Funding: This award was funded by the National Institute for Health and Care Research (NIHR) Health and Social Care Delivery Research programme (NIHR award ref: 17/112/16) and is published in full in Health and Social Care Delivery Research; Vol. 12, No. 48. See the NIHR Funding and Awards website for further award information.