Psychological therapies including dialectical behaviour therapy for borderline personality disorder: a systematic review and preliminary economic evaluation.

OBJECTIVES: To summarise the available evidence on the clinical effectiveness and cost-effectiveness of psychological therapies including dialectical behaviour therapy (DBT) for borderline personality disorder (BPD).

DATA SOURCES: Electronic databases were searched up to March 2005.

REVIEW METHODS: Relevant studies were assessed using standard checklists and data were abstracted by two reviewers using standardised forms. Separate economic evaluations were undertaken for six selected randomised controlled trials (RCTs). Cost-effectiveness was assessed in terms of cost per parasuicide event avoided in all six trials and cost per quality-adjusted life-year (QALY) in four of them. All results are at 2003-4 prices and for 12 months follow-up.

RESULTS: Nine RCTs and one non-RCT of moderate to poor quality were identified in the clinical effectiveness review. They provided some evidence that DBT is more effective than treatment as usual (TAU) for the treatment of chronically parasuicidal and drug-dependent borderline women; that DBT-orientated therapy is more effective than client-centred therapy (CCT) for the treatment of BPD; and that DBT is as effective as comprehensive validation therapy plus 12-Step for the treatment of opioid-dependent borderline women. There was also some evidence that partial hospitalisation is more effective than TAU in the treatment of BPD, good evidence that manual-assisted cognitive behavioural therapy (MACT) is no more effective than TAU in the treatment of BPD and some evidence that interpersonal group therapy is no more effective than individual mentalisation-based partial hospitalisation (MBT) for the treatment of BPD. However, these results should be interpreted with caution as not all studies were primarily targeted to borderline symptoms and there were considerable differences between the studies. The assessment of cost-effectiveness found a mix of results in the four trials of DBT, along with the high levels of uncertainty and the limitations in the analyses. The findings do not support the cost-effectiveness of DBT though they suggest it has the potential to be cost-effective. The results for MBT are promising, though again surrounded by a high degree of uncertainty and for MACT, the analysis suggests that the intervention is unlikely to be cost-effective.

CONCLUSIONS: The overall efficacy of psychological therapies is promising; however, at this stage the evidence is inconclusive. The cost-effectiveness of the intervention in six RCTs examined, however, does not support the cost-effectiveness of DBT although potential is suggested. There is a need for considerable research in this area. This research should involve appropriately powered head-to-head RCTs of psychological therapies; a survey of current practice and the use of the full range of services by people with BPD to inform future economic analyses; full resource-use data collected in the context of pragmatic clinical trials; psychometric assessment of the validity of the EQ-5D or other generic and condition-specific preference-based measures in BPD, and the development of a more formal cost-effectiveness model using the above data.