Response to: ‘A randomised controlled trial of eye movement desensitisation and re-processing (EMDR) in forensic services and in prison’ – Letter to the editor

In their recent letter to the editor of Medicine, Science and Law, Every-Palmer et al. responded to an editorial published in this journal, in which the authors of this paper incorrectly stated that there had not been a randomised control trial (RCT) of Eye Movement Desensitisation and Reprocessing (EMDR) in custodial settings.^1,2 In their letter, Every Palmer et al. describe their RCT of EMDR in forensic inpatient, forensic community mental health, and prison settings, which was published online in early 2024. ³

Their trial investigated the efficacy and risks of EMDR for people with PTSD and psychotic disorders who were in prison or who had been diverted from custody into forensic mental health care. It was a single-blind randomised control trial comparing EMDR therapy to routine care in 24 offenders with psychotic disorders and PTSD. An in-depth description of the methods was described in their study protocol. ⁴

Every-Palmer et al. found that EMDR can be effective, safe and acceptable when used with forensic populations with serious psychiatric co-morbidities and complex trauma histories. ³ After 6 months, 16.7% of participants in the EMDR group still met the cutoff threshold for a diagnosis of PTSD compared with 36.4% in the wait-list group, and EMDR was well tolerated and acceptable to participants. This study by Every-Palmer et al. represents the first RCT of EMDR within prison and forensic populations.

However, we agree with Every-Palmer and her colleagues that a larger-scale trial of EMDR within prisons is needed. In particular, their study was conducted within forensic inpatient and forensic community settings, as well as prisons, and only two participants from the prison population received EMDR within the trial. Given that there are considerable differences between populations detained in forensic hospitals and prisons, we suggest that a prison-only RCT is needed in order to investigate the effectiveness of EMDR in this setting with a larger sample. In addition, given the international differences between prison health-care systems, a UK-based study is needed to investigate whether EMDR can be effectively delivered within this prison system. We welcome a continued dialogue with Every-Palmer and her colleagues and acknowledge the importance of partnership and collaboration to ensure the development of this important area of research internationally.