Patterns and correlates of health service contact prior to serious offences by people with severe mental illness.

Background: Contact with health services prior to offences committed by people with mental illness is an opportunity for intervention and prevention. This study examines the pattern and correlates of health service contact by people with severe mental illness before a serious offence.

Method: Linkage of a cohort of 477 Forensic Patients found not guilty due to mental illness between 1990 and 2016, and statewide databases of contact with emergency departments, hospital admission and outpatient mental health services in the state of New South Wales, Australia.

Results: A total of 84% of the sample had contact with any health service and 76% had contact with an outpatient mental health service prior to the index offence. About two-thirds of the sample had contact with a mental health service in the year before the offence. Factors independently associated with the absence of contact at any point prior to the index offence were non-English-speaking background, being engaged in employment or study, and an absence of childhood abuse or neglect. Although nearly every Forensic Patient had a psychotic illness at the time of the index offence, psychosis was not diagnosed at the time of 61/106 (57.5%) emergency department presentations, in 54/174 (31.0%) hospital admissions and 149/222 (67.1%) attendances at outpatient mental health services prior to the offence.

Conclusions: Most Forensic Patients had contact with health services prior to their offences but many were not identified as having a psychotic illness. Although the symptoms of psychosis may have emerged in the period between contact and the offence, the findings suggest that emerging or underlying psychosis were missed or attributed to other conditions.