Personality disorder and outcome in schizophrenia: A negative systematic review

Abstract

Background It is commonly believed that the presence of personality disorder influences the outcome of schizophrenia but no systematic examination of the literature has been published to examine this. Aims The aim of the current research was to review the literature in a standard systematic way in order to determine the influence of personality disorder on the outcome of schizophrenia in methodologically robust trials. The null hypothesis was that personality disorder had no influence on the outcome of schizophrenia. Method A systematic electronic search of the literature was carried out to identify papers. Relevant papers, written in English, were accessed and assessed for data. Suitable papers were identified to extract outcome data. Results A total of 3 972 papers were identified by the electronic search and two reviewers read all the abstracts. Of these, 97 were identified as potentially containing information about outcome in patients with schizophrenia and comorbid categorical personality disorders and were read in full. No papers satisfied the inclusion criteria of both recording the presence of personality status before treatment and outcome separated by personality pathology and change in schizophrenic symptoms (but several others reported on institutional treatment, reoffending and service usage). Five authors were contacted for further data and none provided usable information suitable for meta‐analysis. Conclusions No research to date has examined the influence of personality disorder on the outcome of patients with schizophrenia in such a way as to indicate whether this form of comorbidity has a significant impact on the natural history or outcome of treatment on schizophrenia. The common belief that personality disorder worsens outcome in schizophrenia remains open to debate, and it is suggested that future research takes the opportunity of addressing this important issue directly. Copyright © 2007 John Wiley & Sons, Ltd.