More Than a Label: Post-Release Re-Offending Predicted by Co-Morbid Diagnoses in an Australian Cohort of Forensic Patients

Kimberlie Dean, University of New South Wales; Justice and Forensic Mental Health Network
Sara Singh, University of New South Wales
Richard Kemp, University of New South Wales
Olav Nielssen, University of New South Wales; Australia and Macquarie University

In a 25-year Australian cohort of men and women found Not Guilty by reason of Mental Illness (NGMI forensic patients; N = 477), we aimed to: establish the sociodemographic, clinical and forensic characteristics of the sample, comparing men and women; to establish rates of post-release reoffending, including for men and women separately; and to test associations between individual characteristics and post-release re-offending in the full sample. Post-release re-offending was considered in terms of officially-recorded charges, proven offenses, violent offenses, and any offending within the first 12 months of release. Women (13.8%) were found to differ significantly from men on a number of key characteristics but, although women had a higher rate of proven offending in the early post-release period, sex was not a predictor of post-release offending overall. Post-release re-offending rates were low (6.3% committed proven offenses in the first 12 months following release) and the only independent predictor of re-offending was a clinically-recorded diagnosis of co-morbid personality disorder (i.e., co-morbid with a primary psychosis diagnosis). The differences identified between male and female NGMI forensic patients, including the differences in reoffending in the early post-release period, have implications for the development of forensic services and interventions, in both inpatient and community settings.

Forensic, NGMI, NGRI, NCRMD, insanity acquittees, criminal responsibility, offending, gender, violence

“The mental health needs of forensic mental health patients are complex and care is often costly…Despite this, the characteristics, needs, and outcomes for this group remain inadequately understood in many jurisdictions, including with respect to the possibility of differences between men and women…Although the rates of re-offending are known to be reassuringly low for forensic patients, there are relatively few studies establishing the factors associated with re-offending that would be useful to guide treating clinicians and tribunals, including with regard to when might be safe to grant release to a community setting…” (p.17-18).

“…Utilizing data from a large NSW cohort of NGMI forensic patients, the current study had three key aims. Firstly, we aimed to establish the sociodemographic, clinical and forensic characteristics of the sample, and to investigate any differences in characteristics between men and women. Secondly, we aimed to establish the post-release re-offending rates for the sample, including for men and women separately, and with re-offending further explored in terms of the occurrence of violence, whether the offense had been proven, and whether offending occurred within the first 12 months following release. Thirdly, we aimed to examine associations between key sample characteristics and post-release re-offending…” (p.18).

“This study presents the results of analysis of a near-complete cohort of male and female NGMI forensic patients (n = 477) ascertained over a 25-year period in the Australian state of New South Wales (NSW). Most of the sample had a severe mental illness, typically attracting a diagnosis of schizophrenia-spectrum disorder…Most of the sample also had at least some contact with mental health services prior to the index offense…The proportion of NGMI forensic patients with previous convictions was high, but only 17.2% of the sample had a recorded history of imprisonment…” (p.24).

“Women comprised about 13.8% of the NGMI forensic patients…and differed from men with regard to a number of demographic, clinical and criminological features. Re-offending rates were found to be low for the sample as a whole (6.3%…) and, while sex was not a significant predictor of re-offending overall, the rate of proven offending during the first 12 months following release was higher for women (13.3% for women and 4.9% for men)…the incidence rate [of re-offending charges during the post-release period] was independently predicted by only one variable – the presence of a clinically-recorded diagnosis of personality disorder, co-morbid with a schizophrenia-spectrum disorder and predominately antisocial in type” (p.24-25).

“…women were more likely to have been in a long term relationship and to have children prior to the index offense, were less likely to have a primary schizophrenia-spectrum diagnosis, less likely to have documented co-morbid substance use disorder, less likely to have a history of head injury, more likely to have a strong family history of mental illness, and less likely to have a history of offending prior to the index offense, when compared to men. Considering the potential implications of these findings, it may be that understanding relationships with intimate partners and children in the context of the rehabilitation and recovery is of particular importance for female forensic services, while the need to prioritize interventions for substance use problems may be reduced, compared to male forensic services. The role of interventions designed to target criminogenic needs may also be less important for female forensic patients and, instead, there may be an increased need to focus on interventions appropriate for individuals with non-psychotic primary psychiatric diagnoses (e.g., interventions for those with primary personality disorder…)…” (p.25).

“…while overall re-offending did not differ by sex, re-offending in female NGMI forensic patients appeared to occur earlier in the post-release period…While there is clearly considerable overlap in the risk factors relevant to violence risk assessment and management for men and women, it is increasingly apparent that for women there may be additional factors or an increased sensitivity to particular factors that are relevant to clinical decision-making…” (p.26-27).

“On univariate survival analysis, we also found several other factors to be significant predictors of re-offending, including a history of substance use problems, being of English-speaking background, and having a history of charges prior to the index offense, but non remained significant in the multivariate model. Despite having a near total-population sample of NGMI forensic patients in NSW over 25 years, our analyses are likely to have suffered from inadequate power to identify independent predictors of re-offending with lower strengths of association…one of the persistent difficulties with identifying clinically-relevant predictors of offending outcomes is the lack of temporally-relevant information about dynamic clinical factors, such as the level of active symptoms of mental illness at the time of any re-offending. Factors that reflect enduring personality and behavioral patterns might be more likely to be identified as the only significant predictors in such circumstances…” (p.27).

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