This article challenges the accepted view that mental illness is the primary cause of homelessness. We examine critically a series of Australian studies which have attempted to estimate the prevalence of mental health problems among the homeless population and argue that the definitions of mental illness often used tend to exaggerate the numbers. We then provide our own estimate, using a study of 4,291 homeless people in Melbourne, and explore the important question of whether mental illness precedes homelessness or derives from it. Finally, we attempt to reframe the debate on mental illness and homelessness in the light of our findings and discuss the policy implications that arise from them.
Estimating the Prevalence of Mental Illness
In the international literature, it is widely recognised that people with mental health issues are over-represented in the homeless population, but there is considerable debate as to the extent of the over-representation (Snow et al. 1986; Wright 1988). There is a similar debate in the Australian literature, where some studies report that 72 to 82 per cent of homeless people are mentally ill, whereas others report that between 12 and 44 per cent have a mental illness.
Australian studies that report a low to moderate level of mental illness draw their samples in different ways and use different methods to assess whether or not people have a mental health issues. Studies that report a higher level of mental illness also draw their samples in different ways, but they have a common definition of mental illness and use a standardised diagnostic tool. First, we review six widely quoted studies to illustrate both approaches.
A large study by the Australian Institute of Health and Welfare (AIHW) (2007) examined the characteristics of 100 400 clients who used the Supported Accommodation Assistance Program (SAAP) in 2004-05. At that time, SAAP was the Australian Government's flagship program to provide accommodation and support services for homeless people. SAAP clients were classified as having a mental illness if they met one of the following criteria: they were referred from a psychiatric unit; they reported psychiatric illness as a reason for seeking assistance; they were provided with, or referred to, psychological or psychiatric services (AIHW 2007: 4). On this basis, the AIHW found that 12 per cent of SAAP clients had mental health issues.
A study by Rossiter, Mallett, Myers and Rosenthal (2003) interviewed 403 homeless young people aged 12 to 20 using SAAP services in metropolitan Melbourne. Young people were defined as homeless if they had left home for two days or longer without their parents' permission and were living in various forms of temporary accommodation, including emergency accommodation, staying with friends and relatives, and sleeping rough. Rossiter and colleagues used the Brief Symptom Inventory (BSI) to assess the teenagers' mental health. The BSI has 53 questions covering such issues as nervousness, feeling lonely, and thoughts about death and dying. Rossiter and colleagues (2003: 17) found that 26 per cent of those surveyed 'reported a level of psychological distress indicative of a psychiatric disorder'.
A study by Flatau (2007) gathered information from 173 people aged 19 or older using 31 services in Western Australia. This included 18 services providing support to homeless people and 13 services providing support to people at risk of homelessness. A survey was used to assess the prevalence of mental health issues. The survey was 'completed by members of the research team or by agency case workers' who asked clients direct questions. However, the survey was supplemented by 'case notes and entry assessments' (Flatau 2007: 13). The research found that 44 per cent had a mental health condition, and depression was the most common form of mental illness (Flatau 2007: 14).
The three studies that reported a low to moderate level of mental illness varied in their operational definition of homelessness and they used different criteria to assess whether or not people had a mental illness. …