Cost-effectiveness of dialectical behavioural therapy versus treatment as usual for autism with suicidal behaviours: single-blind randomised controlled trial.

Abstract

Objective: This study evaluated the cost-effectiveness of dialectical behaviour therapy (DBT) compared to treatment as usual (TAU) for autistic adults with suicidal behaviours.

Method: In a randomised controlled trial, 123 autistic outpatients were assessed over 12 months. Healthcare costs and societal costs were calculated in accordance with the Dutch standard. Outcomes were quality-adjusted life years (QALYs) and treatment response, defined as a reduction of at least 50% in symptoms of suicidal ideation from t₀-t₁₂ as measured by the Suicidal Ideation Attributes Scale (SIDAS), plus achieving SIDAS < 20 at t₁₂ (i.e. below the clinical threshold).

Results: From the healthcare perspective, DBT cost €371 less than TAU while gaining an additional 0.184 QALYs, with a 64% likelihood of being the dominant treatment option. From the societal perspective, DBT has higher costs than TAU by €232 per QALY gained, which can be considered cost-effective given a willingness-to-pay of €50,000 per QALY. DBT also showed better treatment response rates, with less suicidal ideation, at lower costs than TAU. Sensitivity analyses supported these findings.

Conclusion: DBT is a novel treatment for autistic adults with suicidality. It fills a significant treatment gap in lieu of any evidence-based alternative for this population. DBT reduces suicidality, enhances quality of life and is cost-effective across healthcare and societal perspectives, encouraging broader adoption. Future research should assess DBT's long-term impacts and its transferability to other countries and map pathways towards upscaled implementation.