Lindqvist & Skipworth (Reference Lindqvist and Skipworth2000) emphasised the shortage of high-quality randomised trials dealing with the treatment and rehabilitation of mentally disordered offenders and highlighted problems of undertaking such studies. Currently, we are involved in a project, funded by the UK National Health Service Research and Development Programme on Forensic Mental Health, to create a register of randomised controlled trials dealing with the management of violent or aggressive people. Initial searches identified 22 000 citations, over 2000 of which were relevant trials. We are now surveying the subset of 350 trials of most interest to the forensic mental health services. Data on content and quality are being reliably recorded and a report will be produced for publication. Already some of these trials are of sufficient quality to be included in systematic reviews (Reference Brylewski and DugganBrylewski & Duggan, 2000; Reference Fenton, Coutinho and CampbellFenton et al, 2000; Reference White, Bradley and FerriterWhite et al, 2000).

It is likely that Lindqvist & Skipworth are correct to suggest that high-quality studies are rare. Many trialists, however, have used the ‘gold standard’ of mental health care evaluation (World Health Organization Scientific Group on Treatment of Psychiatric Disorders, 1991), the randomised trial, to investigate the value of interventions relevant to forensic services. Much can be learnt from such studies, even if they are of limited quality. Systematic appraisal of such work may inform practice, but certainly guides future research. Lindqvist & Skipworth listed considerable difficulties encountered by trialists of interventions relevant to forensic services. These difficulties have all, to a greater or lesser extent, been considered and addressed, and large, simple randomised trials could overcome most problems. Indeed, many of the treatments commonly used for offenders with mental disorders may be unethical outside of such trials (Reference White, Bradley and FerriterWhite et al, 2000).