A Smartphone-Based Psychological Intervention for Nonsuicidal Self-Injury (Kalmer App): Protocol for a Multicenter...

Area of Science:

• Digital Mental Health
• Adolescent Psychology
• Clinical Psychology

Background:

• Nonsuicidal self-injury (NSSI) is a growing public health concern among adolescents and young adults.
• Existing treatments for NSSI are often inaccessible and not youth-tailored.
• Mobile health (mHealth) interventions offer a scalable and cost-effective approach to support individuals with NSSI.

Purpose of the Study:

• To evaluate the effectiveness of Kalmer, a novel app-based intervention, in reducing NSSI frequency and enhancing emotional well-being in adolescents and young adults.
• To identify predictors of treatment outcomes for app-based interventions targeting NSSI.
• To present the study protocol for a randomized controlled trial investigating the Kalmer intervention.

Main Methods:

• A 2-arm, 6-week randomized controlled trial involving 240 participants aged 14-24 with NSSI.
• The Kalmer app, informed by dialectical behavior therapy and cognitive behavioral therapy, delivers tailored interventions via ecological momentary assessments.
• Participants are randomized to receive either the Kalmer intervention or a control psychoeducational app, with NSSI frequency assessed at baseline, 6 weeks, and 1- and 3-month follow-ups.

Main Results:

• Ethics approval obtained in December 2022; recruitment is ongoing as of January 2026.
• 145 participants have consented and completed baseline assessments.
• Preliminary data indicate high app engagement, acceptability, and positive user feedback on usability and content.

Conclusions:

• The study will provide crucial evidence on the efficacy of a mobile app-based intervention for NSSI.
• It aims to explore potential mechanisms of change within digital mental health interventions.
• Findings will contribute to the development of accessible digital mental health tools for young people experiencing NSSI.