Co-occurring schizophrenia and substance use disorders and offending

This is a powerful study (n=2,861) that provides substantial, evidence from Australia (Victoria) of the costs of co-occurring mental health and substance us disorders across multiple systems and underlines the importance of initiatives attempting to address co-occurring disorders.

The study traces the escalation in substance use by persons with schizophrenia in Victoria in the 25 years in which deinstitutionalisation has occurred. It shows that people with schizophrenia were significantly more likely to sustain criminal convictions, especially for violence (this raises the question of whether transinstitutionalisation - from mental hospital to gaol - has occurred in Victoria in a similar manner to the USA- Wallace & colleagues note that incarceration rates in the general population have also risen steeply in this period). Wallace and colleagues note that convictions for criminal behaviours probably represents an underestimate of actual criminal & violent behaviour - self-report by subjects will show a higher rate of offending.

The research showed that known substance abuse problems among persons with schizophrenia increased from 8.3% in 1975 to 26.1% in 1995 (and this is known substance use problems - mental health agencies recognition of substance use problems is probably still not great in 2004 & was probably worse in 1995)

 Wallace and colleagues examined cohorts in 1975, 1980, 1985, 1990 & 1995 - in each successive cohort the rates of substance use disorder increased and a greater proportion of the total convictions was accounted for by patients with both schizophrenia AND substance use disorders

In their conclusions the authors suggest that if mental health services are to further the interests of both their patients and the community, they must become involved in identifying and treating the social and psychological factors that not only disable the patients they treat but also predispose those patients to continued offending. The findings of the current study challenge clinicians and policy makers to recognize that persons with schizophrenia have high rates of problem behaviours that require improved assessment and treatment and also to ensure that such results are not used to further stigmatize a sick and disadvantaged minority.

The abstract & link to the article is at http://ajp.psychiatryonline.org/cgi/content/abstract/161/4/716?etoc

Abstract also reprinted below

Abstract

OBJECTIVE:

This study examined the pattern of criminal convictions in persons with schizophrenia over a 25-year period marked by both radical deinstitutionalization and increasing rates of substance abuse problems among persons with schizophrenia in the community.

METHOD:

The criminal records of 2,861 patients (1,689 of whom were male) who had a first admission for schizophrenia in the Australian state of Victoria in 1975, 1980, 1985, 1990, and 1995 were compared for the period from 1975 to 2000 with those of an equal number of community comparison subjects matched for age, gender, and neighbourhood of residence.

RESULTS:

Relative to the comparison subjects, the patients with schizophrenia accumulated a greater total number of criminal convictions (8,791 versus 1,119) and were significantly more likely to have been convicted of a criminal offence (21.6% versus 7.8%) and of an offence involving violence (8.2% versus 1.8%). The proportion of patients who had a conviction increased from 14.8% of the 1975 cohort to 25.0% of the 1995 cohort, but a proportionately similar increase from 5.1% to 9.6% occurred among the comparison subjects. Rates of known substance abuse problems among the schizophrenia patients increased from 8.3% in 1975 to 26.1% in 1995. Significantly higher rates of criminal conviction were found for patients with substances abuse problems than for those without substance abuse problems (68.1% versus 11.7%).

CONCLUSIONS: