Effectiveness of psychological and psychosocial interventions for forensic mental health inpatients: A meta-analysis

Abstract

Psychological and psychosocial interventions have significant potential to treat the mental health and criminogenic needs of forensic mental health patients. However, due to a dearth of high-quality evaluation studies there is limited evidence on the effectiveness of these interventions with this population. This review aimed to quantitatively summarise the effectiveness of psychological therapies delivered in forensic hospitals. The literature was systematically searched to identify controlled evaluations of psychological interventions delivered within inpatient forensic psychiatric settings. Twenty-eight studies were included. Methodological quality was assessed using the SIGN Methodology Checklists. Pooled effect sizes were calculated for fourteen outcome domains. Small effect sizes were found favouring psychological treatment over the comparator condition in increasing insight into mental illness, ameliorating symptoms, improving problem-solving ability, reducing pro-criminal attitudes and improving ward behaviour. A medium effect size was found for treatment increasing patients' knowledge of their mental illness. There were few outcomes for which psychological therapy was associated with improvements beyond that of comparison treatment, and these improvements were generally small. Despite more frequent adoption of a randomised-controlled design, methodological quality remains problematic and more well-designed trials are needed to determine the effectiveness of psychological interventions across outcome domains relevant to forensic patients' recovery.