Schizophrenia and criminal offending

University of Western Australia researchers have been investigating the link between schizophrenia and criminal offending in a bid to provide data to counter or temper popular misconceptions.

A team from the UWA Crime Research Centre and the Neuropsychiatric Epidemiology Research Unit (NERU) in the School of Psychiatry and Clinical Neurosciences that is linked to the Centre for Clinical Research in Neuropsychiatry (CCRN), set out to identify the influence of area of residence on the rate of arrests among people with schizophrenia in WA. It was prompted by the fact that little is known in Australia about the social ecology of offending by people with schizophrenia.

Using data collected in Perth between 1985 and 1996, the study found a high prevalence of arrests among the general population in WA – 14.4 percent of the population had been arrested in the 12-year period. But the joint prevalence of having a diagnosis of schizophrenia and an arrest was rare at 0.1 percent.

The study, published by the Australian Institute of Criminology late last year, found that risk factors for offending in the general population were also risk factors for individuals with schizophrenia.

Using area data that included disadvantage, inequality, ethnicity, extent to which people moved house, and urban living, the researchers found that the characteristics of neighbourhoods in which offenders with schizophrenia lived were very similar to those in which non-psychiatric offenders lived. However, they were different from those of people with schizophrenia in general.

Co-author Research Associate Professor Vera Morgan said that unfortunately, compared to the general population, individuals with schizophrenia were more likely to be exposed to social disadvantage and other risk factors that predicted offending in non-psychotic populations.

"For example, the Australian national survey of low prevalence (psychotic) disorders that covered a catchment of 1.1 million people found that the life histories of people with psychosis were marked by long-term educational and economic disadvantage, homelessness, social marginalisation, physical ill-health, high levels of victimisation and rates of substance abuse well above population levels," she said.

"Therefore it is likely that a large component of the risk of offending in persons with schizophrenia stems from their living circumstances rather than as a direct consequence of their mental health status."

The report found that the same area or community processes that generate high arrest rates for individuals with schizophrenia produce high crime rates for the general population.

Dr Morgan said the study's results had important implications for policy and program development in criminal justice and mental health.

There was a greater need for services for people with serious mental illness living in areas characterised by social disorganisation or inequality, she said.

(Source: University of Western Australia: August 2009)