Summary The growing demand for effective treatments for personality disorder has not been met adequately by the development of appropriate clinical services. However, there has been a significant shift from the view that personality disorder is untreatable; we do have treatments that have at least some efficacy and a number of countries have issued national guidance on the treatment of some personality disorders. This chapter summarises some of the current evidence regarding which psychological treatments are effective for personality disorder.
Although every known treatment is used at some time for conditions that are deemed untreatable, almost all of the treatments for personality disorder that carry some element of respectability are included under one of the headings in Table 13.1. In discussing the efficacy of treatments for personality disorders, we have to be aware of the special problems associated with assessment of these conditions:
(a) the high level of comorbidity with other disorders, of both personality and mental state (Tyrer et al, 1997);
(b) the fluctuating nature of personality status over time, mainly as a consequence of concomitant mood changes (Clark et al, 2003);
(c) the need for a long period of observation, preferably at least a year, before a treatment can be said to have been properly evaluated;
(d) the recognition that personality disorder is a multifaceted condition that can be influenced in many different ways and fully justifies the use of what are described as ‘complex interventions’ (Campbell et al, 2000) to treat it. Complex interventions lead to complex evaluations and consequent greater difficulty in interpreting results.
An important distinction in determining the value of an intervention is whether it has been demonstrated in standard practice or under strict experimental conditions. This was first highlighted by Schwarz & Lellouch (1967) in discussing randomised trials, and it is commonly described as the difference between an explanatory trial, i.e. a trial in which treatments are compared under ideal (experimentally manipulated) conditions, and a pragmatic trial, in which the study is carried out under the conditions normally appertaining to ordinary practice. In the latter type of trial, possible confounders to the intervention may be present, and although they could be removed, to do so would create an artificial environment that would not allow the results to be transferred to ordinary practice.