The effectiveness and safety of dialectical behavior therapy for suicidal ideation and behavior in autistic adults: A pragmatic randomized controlled trial

Backgrounds Many autistic people in mental health are suicidal. This study evaluated the effectiveness of dialectical behavior therapy (DBT) v. treatment as usual (TAU) in reducing suicidal ideation and suicide attempts. Methods At six Dutch mental health centers, 123 outpatients (18-65 years) with DSM-5 diagnosed autism spectrum disorder (ASD) and suicidal behavior were randomly assigned to the DBT intervention group (n = 63) or TAU control group (n = 60). Assessments were conducted at baseline, post-treatment at 6 months and 12-month follow-up. The primary outcomes were severity of suicidal ideation and frequency of suicide attempts. The severity of depression and social anxiety were secondary outcomes. Results At end-of-treatment, DBT significantly reduced both suicidal ideation (z = -2.24; p = 0.025; b = -4.41; s.e. = 197.0) and suicide attempts (z = -3.15; p = 0.002; IRR = 0.046; s.e. = 0.045) compared to TAU, but lost statistical significance at the 12-month follow-up. Depression severity significantly decreased with DBT (z = -1.99; p = 0.046: b = -2.74; s.e. = 1.37) remaining so at 12 months (z = -2.46; p = 0.014; b = -3.37; s.e. = 1.37). No effects were observed on social anxiety. Severe adverse events included two suicides in the TAU condition. Conclusions DBT is an acceptable, safe, and short-term effective intervention to reduce suicidal ideation and suicide attempts in autistic adults with suicidal behavior.