Psychological Treatment for Adolescents With Self-injury Within Intensive Mental Health Outpatient Services: Randomized Controlled Pilot Trial

Proportion of adolescents completing the primary clinical outcome, Deliberate Self-harm Inventory - Youth version, either through interview or self-report questionnaire at one-month post-treatment.

Proportion of adolescents completing ≥ six ERITA modules. Only in the experimental condition. Clinician-rated

Therapists will report time for having sessions with adolescents and/or parents or giving feedback on the digital platform. Only in the experimental condition.

CEQ measures treatment credibility and expectancy. Scale points range from 0-9, and 0-100%, where higher scores indicate greater credibility and expectancy. Self-rated by adolescents. Only in the experimental condition.

This checklist measures therapist adherence to emotion regulation therapy. Adapted to be suitable for therapy with adolescents. Only in the experimental condition.

The CSQ measures satisfaction with treatment. This scale has 8 items and a summary score ranging from 8 to 32, with higher scores indicating greater treatment satisfaction. Self-reported (adolescents and parents).

A scale where participants are asked to report, describe, and rate the discomfort/impact of any negative effects or adverse events caused by their participation in the treatment. Participants rate the impact of potential adverse events when it happened and today on a scale from 1 to 4, where a higher score indicates greater impact. Self-reported (adolescents and parents). Adverse events will be recorded by PI throughout the treatment period.

The DSHI-Y is a youth-adaptation of the DSHI and measures the six most common NSSI methods. The primary clinical outcome will be the proportion of treatment remission. Remission will be defined as the absence of NSSI in the past month and measured dichotomously (yes/no). The primary data source will be blinded assessor-rated DSHI-Y. If these data are missing, self-reported DSHI-Y will be used.

The DSHI-Y measures the frequency of the most common NSSI behaviors. Change in NSSI frequency from baseline to respective follow-up will be a secondary outcome. The primary outcome measure will be the clinician-rated DSHI-Y. In cases where clinician ratings are unavailable, the self-rated DSHI-Y will be used.

The DERS-16 measures difficulties in emotion regulation. The total score ranges from 16 to 80, with higher scores indicating greater difficulties. Self-rated (adolescent and parent).

The CGAS measures global functioning on a single item ranging from 1 to 100, with a higher value indicating better functioning. Clinician-rated.

The BSL supplement measures the frequency of self-destructive behaviors. We will measure behaviors of self-harm, suicide attempt, binge eating, self-induced vomiting, high-risk activities, getting drunk, substance use, medication misuse, outbreaks of anger/physical attacks and impulsive/shameful sexual encounters, resulting in a total score between 0 to 40 where a higher score indicates greater frequency of self-destructive behaviors. Self-rated (adolescent).

The CHU-9D measures health related quality of life. The scale has 9 items with a summary score between 9 and 45, where a higher score indicates greater health-related quality of life. Self-rated (adolescent).

The RCADS-25 measures symptoms of depression and anxiety in children and adolescents. This version has 25 items with a total score between 0 and 75, with higher scores indicating greater levels of symptoms. Self-rated (adolescent).

The CCNES-A measures parental coping in response to adolescents' negative emotions. The CCNES-A consists of nine hypothetical scenarios accompanied by six types of responses (i.e., emotion focused, problem-focused, minimization, punitive, expressive encouragement, and distress responses). Separate summary scores are calculated per subscale (type of response) and ranges from 1 to 7, with higher scores indicating greater usage of a certain parental coping style. Self-rated (parent and adolescent).

The WSAS-Y measures functional impairment in school, everyday life, friends and social life, recreation and hobbies, and family and close relationships.This 5-item scale generates a summary score between 0 and 40, with higher scores indicating greater impairment. Youths rate their own impairment. Self-rated.

The WSAS-P measures functional impairment in school, everyday life, friends and social life, recreation and hobbies, and family and close relationships.This 5-item scale generates a summary score between 0 and 40, with higher scores indicating greater impairment. Parents rate their youth's impairment. Self-rated.

CEQ measures treatment credibility and expectancy. This version of the scale has 1 item ranging from 0 to 100, with higher scores indicating greater credibility/expectancy. Self-rated (adolescent).

The C-SSRS - 6 item version measures the frequency and severity of suicidal ideation and behaviors. Clinician-rated.

Degree and type of care consumption as registered by the health care. Registry data from the local Stockholm register for Child and Adolescent Mental Health Services.

ISAS measures frequency, function, age of onset, experience of, and willingness to stop engaging in self-injury. There are 39 items describing common functions of self-injury. Participants are asked to rate if a certain function applies to them, by marking the statement as "Not relevant", "Partly relevant", or "Very relevant". Self-rated (adolescent).

Current mental health disorders, age, previous and current treatment. Clinician-rated. Gender and sexual orientation. Self-rated (adolescent). Country of birth, living situation, parental occupation, parental academic degree, and parental history of mental health disorders. Self-report (parent)