Editor's note

The literature on effective treatments of the personality disorders is quite large but evidence remains sparse. There are a number of personality disorders for which there is absolutely no evidence and/or no studies examining possible evidence for efficacy, and these disorders, schizoid, histrionic, narcissistic, obsessive-compulsive and dependent are not covered in this chapter (but mentioned in the following one on other less-established treatments for personality disorder). Many descriptions of treatment for these disorders are really combinations of theory with clinical supposition but very little evidence. The evidence for some psychotherapeutic intervention is strongest for borderline personality disorder (BPD) and the evidence for psychopharmacological interventions is strongest for schizotypal personality disorder (STPD). Even well-designed studies are confounded by Axis I and Axis II co-morbidities, and this limits interpretation of the findings. The reader will note the importance given to the structuring and organization of treatment and might also consult the chapter on complex interventions in evaluating the significance of the findings.

Introduction

The definition of personality disorder (PD) remains controversial. Both the DSM-IV and ICD-10 take a categorical approach to the diagnosis of PD defining different types of personality according to descriptive criteria. Tyrer et al. (1990), however, found little evidence that categories of personality disorder were helpful in determining response to treatment or indeed that they had any predictive value at all. Research orientated methods rely on structured and semi-structured interviewing or self-report screening measures. Although this improves reliability somewhat, the approach remains unsatisfactory (Pilkonis et al., 1995).