Predicting community violence from patients discharged from acute mental health units in England

To investigate the validity of risk factors and established risk measures in predicting community violence in an acute mental health sample up to 20 weeks post-discharge.

Prospective cohort follow-up study conducted between January 2006 and August 2007. Baseline assessments were conducted while participants were inpatients. The measures were rated following interview with the participants, record review and speaking to someone who knows the person well (e.g. friend, relative, carer). Baseline measures were then compared with frequency and severity of violence in the community post-discharge at 20 weeks.

In the 20-week period post-discharge, 29 (25.4%) of the 114 participants were violent. All the risk measures and measures of impulsiveness and anger were predictive of violence where p < 0.05. The HCR-20 total, psychopathy and clinical factors were strongly correlated with the frequency of violence where p < 0.05.

The risk factors and risk measures that have been found to be predictive in forensic samples are also predictive in acute mental health samples, although the effects are not as large. Future research needs to be conducted with a larger sample to include investigation of differences in risk factors based on gender and social support. Services and clinicians need to consider how to integrate findings into useful frameworks to support decisions and contribute to managing risk. This should assist in identifying interventions aimed at preventing community violence.