Dr Simpson's research interests are in the area of mental illness and violence, from its epidemiology, though evaluation and clinical care and outcomes. This covers both the areas of care prior to and in hospital to models of care in prisons and community for people with serious mental illness. Dr Simpson was also Co-editor of the text book on Psychiatry and Law in 2007 and has assisted in writing guidelines on risk assessment and formulation in a recovery paradigm. Dr Simpson promotes and participates in research that contributes to our understanding of how to better work with people with forensic mental health needs, at system and individual levels.