This paper investigates the cost-effectiveness of dialectical behaviour therapy (DBT) for treating individuals with borderline personality disorder (BPD) in a community setting in Ireland, in the short term.

Resource utilisation and effectiveness data were collected as part of the National DBT Project, Ireland, and are incorporated into a cost-effectiveness analysis. The perspective taken was that of the service provider and payer. Direct health resources were included and effectiveness was measured using the EQ-5D-5L questionnaire. To examine cost-effectiveness, incremental costs are compared with incremental quality-adjusted life years, to estimate an incremental cost-effectiveness ratio. A probabilistic sensitivity analysis was employed to investigate parameter uncertainty. Scenario analyses are employed to investigate cost-effectiveness of DBT with varying assumptions around effectiveness and costs.

The baseline analysis reveals that DBT is more expensive and more effective than routine clinical care (without DBT). The low incremental cost-effectiveness ratio suggests DBT can be considered cost effective in the short term. In each scenario analyses considered, the probability that DBT is cost effective is greater than 50%.

Mental health care provision, including that of DBT, varies across jurisdictions, necessitating economic evaluations of current practice in community-based services, on a country-by-country basis, to inform resource allocation decisions. In line with previous research, the analysis here indicates DBT can be considered cost effective in the short term. Future data collection on alternative comparators and long-term outcomes associated with DBT is warranted to investigate the longer term cost-effectiveness of DBT.