Abstract
Borderline Personality Disorder (BPD) is considered to be a complex and difficult disorder to treat effectively due to manifestations that affect many aspects of social and psychological functioning. Of most concern for services treating BPD is the frequency of suicidal and parasuicidal behaviour that requires inpatient hospitalisation. NICE guidelines (2009) currently recommend psychological therapies for BPD that are not brief (less than three months). Two of these are Dialectical Behaviour Therapy (DBT) which is rooted in the principles of Cognitive Behavioural Therapy and the psychodynamically orientated Mentalisation Based Therapy. Randomised Controlled Trials (RCT) examining clinical efficacy of each therapy reveals evidence that both treatments are potentially successful in reducing suicidal and parasuicidal behaviour compared to standard psychiatric treatment. RCTs of MBT and related follow-ups were conducted by the originator of MBT so require independent replications. Isolation of the individual components of MBT is also recommended in order to examine the influence of each component on improvements in functioning of BPD clients. Additional examination of clinical efficacy and cost effectiveness requires RCTs of both treatment modalities that utilise larger sample sizes and consistent measures so that cost effectiveness can be more accurately predicted. An RCT that directly compares MBT with DBT is recommended in order to make more meaningful conclusions about relative clinical and cost effectiveness.