Mental illness and mortality among homeless people

Abstract

Mental illness and mortality among homeless peopleHomelessness is a signi®cant problem in the urban centers of many western countries.According to the United Nations, `absolute homelessness' refers to people who sleep outdoors, in vehicles, or in abandoned buildings.In developed countries, many people who would otherwise be `absolutely homeless' sleep in shelters run by government or charitable organizations.`Relative homelessness' refers to people whose physical shelter does not meet basic standards of health, safety, security of tenure and affordability.Most research on homelessness focuses on people who are absolutely homeless or living in homeless shelters, and this is the de®nition adopted here.The precise size of the homeless population is unknown in most jurisdictions.Estimates of the number of homeless people in the United States range from 250 000 to more than 1 million (1).In Canada, homeless people probably number in the tens of thousands.Each night more than 4000 individuals sleep in homeless shelters in Toronto, Canada's largest city (2).London has a large homeless population (3), and about 2000 homeless people live in Madrid (4), but relatively little has been published on homelessness in other European cities.Since the early 1980s, many studies have documented the high prevalence of mental illness among homeless people (5).Early efforts often used weak research designs in which small convenience samples of homeless people underwent non-standardized interviews.Recent studies have adopted more rigorous methodology, with explicit de®nitions of homelessness, clearly speci®ed random sampling methods, adequate sample size and the use of standardized diagnostic instruments (6).Despite these advances, most cross-sectional studies are biased towards overestimating the prevalence of mental illness among the homeless (7).This bias occurs because homelessness tends to last longer in people with mental illness than in This issue of