Jail incarceration, homelessness, and mental health: a national study

This study sought to investigate the rates and correlates of homelessness, especially mental illness, among adult jail inmates.

Data from a national survey of jail inmates (N=6,953) were used to compare the proportion of jail inmates who had been homeless in the previous year with the proportion of persons in the general population who had been homeless in the previous year, after standardization to the age, race and ethnicity, and gender distribution of the jail sample. Logistic regression was then used to examine the extent to which homelessness among jail inmates was associated with factors such as symptoms or treatment of mental illness, previous criminal justice involvement, specific recent crimes, and demographic characteristics.

Inmates who had been homeless (that is, those who reported an episode of homelessness anytime in the year before incarceration) made up 15.3% of the U.S. jail population, or 7.5 to 11.3 times the standardized estimate of 1.36% to 2.03% in the general U.S. adult population. In comparison with other inmates, those who had been homeless were more likely to be currently incarcerated for a property crime, but they were also more likely to have past criminal justice system involvement for both nonviolent and violent offenses, to have mental health and substance abuse problems, to be less educated, and to be unemployed.

Recent homelessness was 7.5 to 11.3 times more common among jail inmates than in the general population. Homelessness and incarceration appear to increase the risk of each other, and these factors seem to be mediated by mental illness and substance abuse, as well as by disadvantageous sociodemographic characteristics.