Homelessness: Rates for General Population and People with Serious Mental Illness

Volume 2, Number 2; March 1995


This Issue Brief integrates the results of two studies, one on the rates of homeless and the other on the mental health of the homeless. Both were conducted by Dennis Culhane and colleagues in New York City and Philadelphia.

Summary

The number of persons who become homeless has been vastly underestimated by previous research. A much smaller percentage of homeless adults have serious mental disorders than found in earlier studies. However, individuals with mental disorders are likely to have greater difficulty exiting the cycle of homelessness.

The Culhane Study:


Using longitudinal approach, demonstrates that homelessness is a more common experience than has been captured in earlier studies, affecting 3% of the New York and Philadelphia populations over five years.
Reveals that there is a disproportionate number of minorities and children, particularly African Americans, who are homeless or at risk of becoming homeless.
Suggests that the current emphasis on using shelters and transitional housing programs to reduce homelessness may not be optimal.
Concludes that further effort should link data sets used in this study with health care data to analyze the impact of homelessness on health care utilization and costs.

Culhane's conclusions are different from those reached by earlier studies.

Previous studies used "snapshot", cross-sectional surveys of homeless shelters, which are useful for shelter capacity planning, but have captured only a fraction of the population that has confronted homelessness

Single point in time studies:


Over-represent certain populations and misportray these populations as stable and chronically homeless.
Inflate the proportional representation of individuals who stay in shelters longer, such as individuals with substance abuse and homeless families.
Previous homelessness studies estimate that between 200,000 and 700,000 individuals in the United States (0.11 percent to 0.50 percent of the population) are homeless at any given time.

- A 1984 Department of Housing and Urban Development (HUD) study, the first by the federal government, estimated between 250,000 to 350,00 people (0.11 and 0.15 percent of the population) were either living in shelters or on the streets on an average night between December 1983 and January 1984.

- A 1986 one night survey in Boston found 0.49 percent of the population homeless.

- A 1988 study in Chicago documented an even lower rate of homeless (0.08 percent).

Culhane's Longitudinal Study of Homelessness

Longitudinal data indicates that homelessness is a greater social problem than previously thought.


Culhane's studies estimate a much larger homeless population.

- In 1992, nearly 1 percent of Philadelphia's population and more than 1 percent of New York City's population used the public shelter systems at least once.

- Over a three year period, 2.77 percent of the population in Philadelphia and 2.21 percent of the population in New York used the public shelter system.

Differential in Homeless population in Philadelphia and New York using cross-sectional versus longitudinal studies


City 	       1990  	      1990-1992	     1992 	    1988-1992	
	       1 day survey   1 year survey  3 year survey  5 year survey


Philadelphia   0.22 	      0.96 	     2.77 	    na


New York       0.32 	      1.17 	     2.21 	    3.27

Culhane's Study of Mental Disorders and the Homeless

Using the longitudinal data, Culhane and colleagues June Averyt and Trevor Hadley found a smaller percentage of serious mental disorders among homeless adults than earlier studies had predicted.


Previous studies based on single point in time samples, estimate that 30% - 35% of homeless adults have a serious mental illness (SMI).
Longitudinal studies using data from 3 years of shelter admissions found that 11% of all homeless adults have a SMI.

- If children were included in the prevalence estimates, the proportion of all homeless with a SMI would decline to 6.5%.


One-half of the shelters' adult population received prior treatment for a mental illness or substance abuse problem between 1985 and 1993.
32 percent of all adults admitted to shelters were treated for substance abuse problems.
26 percent of SMI's and 34% of people with substance abuse problems were hospitalized within 120 days of their first shelter admission.
SMI's were more prevalent among single homeless adults than homeless parents (12.1% vs. 6.2%)

- While 7.7% of single homeless adults had a prior mental health treatment for schizophrenia, only 1.7% of parents did.

- 36% of single homeless adults also had prior treatment for drug or alcohol dependency, while 19% of parents were identified in the category.

Culhane's study examined Philadelphia's homeless population between 1990 and 1993.

The study found:


Approximately 6% of Medicaid recipients receiving mental health treatment were homeless at some time.


Approximately 9% of people with schizophrenia in Philadelphia were homeless.
20% of the Medicaid reimbursed inpatient-substance abuse population became homeless during the study time period.

Policy and Research Implications


Most people who use shelters in Philadelphia and New York do so on a short term and/or intermittent basis. They are not "chronically" homeless.

- These studies show the need for stabilization assistance for those who are at risk of becoming homeless and those with short term and or intermittent housing emergencies.


A proportionately small group of people with a SMI become homeless.

- This suggests the need for an intervention to divert such persons from shelters, including a targeted crisis service, crises residential program, in-home support and stabilization services or transitional housing.


Homeless people are significant consumers of health care services, particularly inpatient care for mental illness and substance abuse.

- More research is needed to examine the impact of homelessness on services and costs.


The US Center for Mental Health Services is currently developing a homelessness prevention/intervention model that might be useful for future planning.

This Issue Brief integrates the results of two studies, one on the rates of homeless and the other on the mental health of the homeless. Both were conducted by Dennis Culhane and colleagues in New York City and Philadelphia.

The number of persons who become homeless has been vastly underestimated by previous research. A much smaller percentage of homeless adults have serious mental disorders than found in earlier studies. However, individuals with mental disorders are likely to have greater difficulty exiting the cycle of homelessness.


Using longitudinal approach, demonstrates that homelessness is a more common experience than has been captured in earlier studies, affecting 3% of the New York and Philadelphia populations over five years.
Reveals that there is a disproportionate number of minorities and children, particularly African Americans, who are homeless or at risk of becoming homeless.
Suggests that the current emphasis on using shelters and transitional housing programs to reduce homelessness may not be optimal.
Concludes that further effort should link data sets used in this study with health care data to analyze the impact of homelessness on health care utilization and costs.

Single point in time studies:


Over-represent certain populations and misportray these populations as stable and chronically homeless.

- Inflate the proportional representation of individuals who stay in shelters longer, such as individuals with substance abuse and homeless families.


Previous homelessness studies estimate that between 200,000 and 700,000 individuals in the United States (0.11 percent to 0.50 percent of the population) are homeless at any given time.

- A 1984 Department of Housing and Urban Development (HUD) study, the first by the federal government, estimated between 250,000 to 350,00 people (0.11 and 0.15 percent of the population) were either living in shelters or on the streets on an average night between December 1983 and January 1984.

- A 1986 one night survey in Boston found 0.49 percent of the population homeless.

- A 1988 study in Chicago documented an even lower rate of homeless (0.08 percent).


Culhane's studies estimate a much larger homeless population.

- In 1992, nearly 1 percent of PhiladelphiaÕs population and more than 1 percent of New York CityÕs population used the public shelter systems at least once.

- Over a three year period, 2.77 percent of the population in Philadelphia and 2.21 percent of the population in New York used the public shelter system.


Previous studies based on single point in time samples, estimate that 30% - 35% of homeless adults have a serious mental illness (SMI).
Longitudinal studies using data from 3 years of shelter admissions found that 11% of all homeless adults have a SMI. - If children were included in the prevalence estimates, the proportion of all homeless with a SMI would decline to 6.5%.
One-half of the sheltersÕ adult population received prior treatment for a mental illness or substance abuse problem between 1985 and 1993.
32 percent of all adults admitted to shelters were treated for substance abuse problems.
26 percent of SMIÕs and 34% of people with substance abuse problems were hospitalized within 120 days of their first shelter admission.
SMI's were more prevalent among single homeless adults than homeless parents (12.1% vs. 6.2%)

- While 7.7% of single homeless adults had a prior mental health treatment for schizophrenia, only 1.7% of parents did.

- 36% of single homeless adults also had prior treatment for drug or alcohol dependency, while 19% of parents were identified in the category.

The study found:
Approximately 6% of Medicaid recipients receiving mental health treatment were homeless at some time.
Approximately 9% of people with schizophrenia in Philadelphia were homeless.
20% of the Medicaid reimbursed inpatient-substance abuse population became homeless during the study time period.
Most people who use shelters in Philadelphia and New York do so on a short term and/or intermittent basis. They are not "chronically" homeless.

- These studies show the need for stabilization assistance for those who are at risk of becoming homeless and those with short term and or intermittent housing emergencies.


A proportionately small group of people with a SMI become homeless.

- This suggests the need for an intervention to divert such persons from shelters, including a targeted crisis service, crises residential program, in-home support and stabilization services or transitional housing.


Homeless people are significant consumers of health care services, particularly inpatient care for mental illness and substance abuse.

- More research is needed to examine the impact of homelessness on services and costs.


The US Center for Mental Health Services is currently developing a homelessness prevention/intervention model that might be useful for future planning.

Funding for Shelter Admissions study supported by Fannie Mae, Office of Housing Research. Funding for the integration of mental health data supported by funds from Ittleson Foundation and the U.S. Center for Mental Health Services. Shelter admissions study is (in print) in Volume 5, issue 2 of Housing Policy Debate, a publication of Fannie Mae. Integration of Mental Health data is in a forthcoming manuscript developed under contract for U.S. Center for Mental Health Services.