The study evaluates the effect of Dialectic Behavior Therapy Skills System (DBT-SS) in individuals with Intelligence Quotient 65-85 and recurrent self-harm. The study is primarily descriptive with 6 cases followed by repeated measurements (weekly; time series analysis). Primary outcome measure is frequency and severity of self-harming behavior, reported weekly 4 weeks before the start of the intervention, throughout the intervention and 12 weeks after the intervention has stopped.

Not many psychotherapies are adapted to suit individuals with Intelligence Quotient(IQ) in the lower normal range. For individuals diagnosed with cognitive disability and self-harm, psychiatric treatment as usual often consists of only supportive meetings and sometimes heavy medication.

Dialectical Behavior therapy (DBT) is one of the evidence based treatments for individuals with self-harm and Borderline Personality Disorder. It is a comprehensive, multi component treatment, usually lasting a year or more. When offering DBT to individuals with cognitive disabilities or IQ in the lower normal range, it is necessary to alter the individual therapy procedures and skills group materials, while remaining adherent to DBT principles.

The Skills System is an adaptation of the standard DBT skills for individuals with cognitive challenges, well suited for IQ 65-85. When adapted DBT individual therapy integrates the Skills System as the skill group curriculum the treatment is called DBT-Skills System (DBT-SS). DBT-SS comprises weekly individual sessions, weekly group education and separate education for caregivers and/or near standing persons. The method is tested with positive effects on problem behaviors, however results need to be reproduced, and further tested in a randomized controlled trial. The handouts from Skills System has recently been translated to Swedish.

The current study aims to investigate the effect of Skills system on individuals with self-harm, IQ 65-85 and three or more symptoms of borderline personality disorder. A single-case time series design will be used with repeated, weekly measurements before, during and after the intervention is provided. 6 participants will be recruited in a pilot study, to investigate the feasibility of the method in a Swedish setting. Main outcome measures are frequency and severity of self-harming and aggressive behaviors, number of days with hospital admission and coercive care, number of medications, and self-rated level of daily functioning. Participation will last 64-70 weeks depending on when the group therapy starts in relation to enrollment.

Inclusion Criteria:

• Ongoing contact with adult psychiatric clinic
• Intelligence Quotient 65-85
• Current self-harming behaviour at least twice the last six months
• Staff from residential care or near standing persons are able to participate in the treatment by participating in group sessions.

Exclusion Criteria:

• Schizophrenia or Bipolar illness type 1
• Substance abuse
• Non-psychiatric disorder significantly contributing to symptoms.