Association between Dual Diagnosis and Offending in a Forensic Psychiatric Population. Identification of Factors that Reduce the Likelihood of Offending

Investigator: Anthea Lemphers

Supervisor: James Ogloff

Rationale and aims:

  • Dual diagnosis (co-occurring substance misuse/dependence and mental illness) is associated with a significantly higher risk of offending than mental illness alone.
  • There are few prospective examinations of the association between dual diagnosis and offending and only limited research regarding factors that may mitigate the risk of offending. This study aims to:
  • help identify the legal contexts and the components of treatment services which effectively prevent violence among persons with major mental disorders
  • provide information about the types of patients who benefit from such programmes
  • assess the validity of the HCR-20 to predict the risk of criminality and violence among persons suffering from major mental disorders.


  • Participants comprise 65 patients discharged from the Thomas Embling Hospital
  • A semi-structured interview was used to obtain socio-demographic information.
  • The Structured Clinical Interview for DSM-IV (SCID – Axis I and II) was used to determine participants’ psychiatric diagnosis.
  • Other information collected related to history of psychiatric treatment, criminal history, history of aggressive behaviour, history of psychosocial functioning, mental disorder and criminality among family members.
  • Risk of future offending and aggressive behaviour was assessed using the HCR-20, Psychopathy Checklist, Revised, 2nd Edition (Hare, 2003) and Level of Service Inventory Revised (LSI-R). Participants were followed up in the community to determine their offending behaviour and contact with psychiatric services.


Ogloff, J. R. P., Talevski, D., Lemphers, A., Wood, M., & Simmons, M. (2015). Co-occurring mental illness, substance use disorders, and antisocial personality disorder among clients of forensic mental health services. Psychiatric Rehabilitation Journal, 38(1), 16-23. doi: 10.1037/prj000008