Emotion regulation as a mediator of dialectical behaviour therapy for autistic adults with suicidal ideation

Dialectical behaviour therapy (DBT) effectively reduces suicidality in autism by improving emotion regulation (ER), yet its underlying therapeutic mechanism is unclear. This study explores ER factors as mediators in DBT’s impact on suicidal ideation in autistic individuals. Data from 123 adult outpatients with autism and suicidal behaviours were randomly assigned to DBT (n = 63) or treatment as usual (n = 60). Suicidal ideation was assessed using the Suicidal Ideation Attributes Scale, and six ER factors were measured with the Difficulties in Emotion Regulation Scale. Structural equation modelling compared a non-sequential model with a sequential model targeting ER factors in the following order: reducing suicide risk, enhancing emotional awareness, consolidating skills, and aligning coping strategies with long-term goals. ER mediated 67% of the total treatment effect. In the non-sequential mediation model, path coefficients were generally small (β ≤ 0.32) and largely not significant. Conversely, in the sequential model, path coefficients were stronger (range: 0.23 ≤ β ≤ 0.92) and all statistically significant (p < 0.01). DBT effectively reduces suicidal behaviour in autistic individuals, with ER playing a profound mediating role. Sequential targeting of ER factors cascades the therapeutic process, highlighting the importance of structured intervention.