Internet-delivered Emotion Regulation Individual Therapy or Adolescents (IERITA) With Self-injury Within Child and Adolescent Mental Health Services

Nonsuicidal self-injury (NSSI) is a growing and urgent global health crisis among youth. It is associated with substantial individual and societal costs, including increased risk of suicide attempts. Scalable and evidence-based treatments are needed but lacking. Digital interventions can be one promising solution. A recent study shows that a novel brief digital treatment, IERITA, can be efficacious compared to treatment as usual only. However, not all respond sufficiently to standardized treatment, such as IERITA, and continued NSSI entails risks and suffering.

In this randomized controlled trial, participants will be randomly allocated (1:1) to standard IERITA or adaptable IERITA. All participants will first receive standard IERITA for four weeks. In treatment week four, or earlier if the adolescent is at risk of discontinuation, classification of non-remission/remission will be conducted. Adolescents allocated to adaptable IERITA and classified as likely non-remission, will change to adapted IERITA (e.g., personalized dose and delivery of treatment) for the remaining weeks (until week 12) while all other participants will continue with standard IERITA. Data will be collected pre-treatment, during treatment, post-treatment, one- three- and twelve-month post-treatment, and in public registers up to ten years post-treatment. The primary endpoint is one-month post-treatment.

The primary aim is to evaluate efficacy of an adaptable treatment strategy for adolescents at risk of non-remission. Secondary aims include implementation, cost-effectiveness, moderators and predictors, distal effects, algorithm performance, and psychometrical evaluations. The specific objectives are:

PRIMARY AIM

1. Determine the efficacy of adaptable IERITA compared to standard IERITA for adolescents at risk of non-remission at one-month post-treatment (primary endpoint) and to assess the durability of effects at three-month follow-up

SECONDARY AIMS 2. Determine the cost-effectiveness of adaptable IERITA compared to a standard IERITA. 3. Explore the implementation (reach, satisfaction, adherence, level and type of resources, utility) of IERITA in child and adolescent mental health services care. 4. Investigate predictors and moderators of treatment outcome. 5. Evaluate distal outcomes and long-term effects of adaptable IERITA compared to a standard IERITA. 6. Explore the experience of being an IERITA therapist. 7. Evaluate the performance of the algorithm predicting treatment non-remission. 8. Evaluate the psychometric properties of the Deliberate Self-harm Inventory - Youth version (DSHI-Y). 9. Evaluate the agreement between self- and assessor-rated NSSI.

Statistical plan is found at: https://osf.io/6h7fe/overview

This project is sponsored by the Swedish Research Council (number 2024-03122), Fonden för Psykisk Hälsa, Stiftelsen Söderströmska Königska (number SLS-1031985), and Thuring Foundation (2025-186).

• Deliberate Self-harm Inventory - Youth version (DSHI-Y) [Time frame: Baseline, one-, three- and twelve-months post-treatment]
• Children's Global Assessment Scale (CGAS) [Time frame: Baseline, one-, three- and twelve-months post-treatment]
• Difficulties in Emotion Regulation Scale - 16 item version (DERS-16) [Time frame: Baseline, one-, three- and twelve-months post-treatment]
• Child Health Utility 9D (CHU-9D) [Time frame: Baseline, one-, three- and twelve-months post-treatment]
• Borderline symtom checklist supplement (BSL) [Time frame: Baseline, one-, three- and twelve-months post-treatment]
• The Revised Child Anxiety and Depression Scale-Short Version (RCADS-25) [Time frame: Baseline, one-, three- and twelve-months post-treatment]
• The Coping with Children's Negative Emotions Scale Adolescent Version (CCNES-A) [Time frame: Baseline, one-, three- and twelve-months post-treatment]
• Trimbos/iMTA questionnaire for Costs associated with Psychiatric illness (TIC-P) [Time frame: Baseline, one-, three- and twelve-months post-treatment]