MHDCD Project

Australians with MHDCD in the CJS Project


The Mental Health Disorders and Cognitive Disabilities (MHDCD) in the Criminal Justice System (CJS) study involves a cohort of 2,731 people drawn from the 2001 NSW Prisoner Health Survey and from the NSW Department of Corrective Services Disability Unit Database. This project represents an innovative approach to researching complex populations by creating a detailed dataset on the life-long Criminal Justice (CJ) involvement for a cohort of offenders. This study uses linked but de-identified extant administrative records from The ARC project, and has partnerships with and/or collaboration from all CJS agencies.

  • Corrective Services
  • Police
  • Juvenile Justice
  • Courts
  • Legal Aid and human service agencies;
  • Housing
  • Ageing Disability and Home Care
  • Community Services
  • Justice Health
  • Health NSW (giving access to Mortality, Pharmacotherapy and Admitted Patient databases).

Linking data across CJS sub-systems with Health and Human Services data is revealing a coherent picture of the multiple factors contributing to the complicated pathways of people with MHDCD into and through the CJS. It is also assisting in the development of new interventions to address offending, preventative health, duty of care and human rights needs.

This project has developed a unique and innovative method of collecting, merging, and analysing data relating to complex individuals and populations such as those who experience homelessness. Merging data across the criminal justice sub-systems and with relevant human services was seen as a highly beneficial way to provide a broad, trans-CJS and human service, dynamic understanding of persons with MHDCD’s criminal justice involvement. It sidesteps the problem of using prospective, life-course, or longitudinal tracking approaches, which potentially require up to 30 years or more and risk yielding limited numbers of persons in the groups of interest in any case


The Objectives of the study:

  • Construct a detailed data set on the life-long criminal justice involvement for a cohort of offenders identified by existing Justice Health (JH) data as having MHDCD, using linked but de-identified extant administrative records from all criminal justice agencies.
  • Integrate into the linked data set this cohort’s involvement with mental health, disability and public housing by drawing relevant data from these human services’ departmental records.
  • Provide outcome data through the statistical analysis of these records.  Particulary in such key indices as;
    • Gender
    • Age
    • Type of first involvement
    • Numbers and types of cautions, arrests, court appearances and their outcomes
    • Community based orders, including breaches and revocations
    • Incarceration/reincarceration
    • Sentence lengths
    • Bail conditions
    • Use of social housing, mental health and disability services
    • Levels of mortality.
  • Draw a purposeful stratified subset of 250 records to create “life-course criminal justice histories”. These will shed light on what actually happens at points of diversion or support; by inference what would have prevented entry to the criminal justice system or contributed to a worsening of the situation.
  • Provide the basis for further targeted or specific secondary analyses of the linked data, some based on new directions for interventions with this population as identified in the initial study.
  • Identify current gaps in policy, protocols and service delivery and areas of improvement for CJS, as well as relevant human service agencies in regard to people with MHDCD.

Research Team:

Chief Investigators

Professor Eileen Baldry, Dr Leanne Dowse, Emeritus Professor Ian Webster

Project Staff:

Data Manager Melissa Clarence


The approach that has been created for this study combines qualitative and quantitative methods to give a rich detailed dataset large enough on which to perform robust statistical analyses, as well as develop typical pathways. Such inclusive data linking or merging had not been attempted in Australia (nor internationally as far as can be ascertained). The current MHDCD dataset has been established using a confirmed cohort of interest compiled into a relational database using MS SQL server 2000. Each individual in the cohort is matched in each agency, and all matches for each person for that agency were added to the SQL database as an agency specific subset. This allows merging of data related to any individual from any sub-set with any other sub-set, with the potential to create both specifically related subsets of interest, and overall administrative life course ‘pathways’. The dataset is stored on a secure IT Services facility at the UNSW and is not accessible to anyone other than the data manager.

One early theoretical direction being taken is to explore the nature of the space in which these persons live. They appear to be cycling around in a liminal, marginalised, community/criminal justice space in which housing / homelessness is a key factor (Dowse et al 2009). This situation is not just attributable to social exclusion; it is centered on the development of a life space straddling the community and criminal justice institutions, into which these persons are funneled.

It is theorized that this space is created through a confluence of personal, systemic and institutional circumstances that are currently poorly understood. It is hypothesised that, if more timely, targeted and appropriate support, and more culturally appropriate support for Indigenous persons (24% of the cohort), had been given at a variety of particular points such as early school education, early family support, childhood disability support, and so on, as revealed in the pathways, then there would have been a reduced chance of eventual imprisonment

Initial Findings

  • Those with complex needs (dual/comorbid diagnoses and multiple combinations) have significantly earlier police events, higher juvenile justice involvement, offences, convictions and imprisonments than the single and no-diagnosis groups
  • Almost all of the MHDCD group were clients of Legal Aid

  • Those with cognitive impairment in combination with any other disability had the highest rates of CJS involvement

  • Those with MHD&CD have experienced very poor school education and low disability service recognition and support; there has been a strong housing response but further analysis is being undertaken to determine why tenancies failed.
  • Only one quarter of those with Intellectual Disability (ID) and virtually none of those with Borderline functioning were clients of Aging Disability and Home Care (ADHC). Of those clients of ADHC, 79% became clients after going to prison. Those becoming clients of ADHC after going to prison then fared significantly better than previously, especially in regard to stable supported housing, and than their peers who are not ADHC clients.


 Research Partners

NSW Police

The NSW Police Force has been a key partner from the inception of the MHDCD project providing very detailed data from its COPS database on each of the 2,731 individuals in the MHDCD dataset. NSW Police Force and the MHDCD team have presented joint papers at a number of conferences and are publishing a number of papers and chapters on the MHDCD data as well as an allied project, the Mental Health Frequent Presenters to Emergency Services Project.

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