Individual Adults & Homelessness

Homelessness exists when people lack safe, stable, and appropriate places to live. Sheltered and unsheltered people are homeless. People living doubled up or in overcrowded living situations or motels because of inadequate economic resources are included in this definition, as are those living in tents or other temporary enclosures.


Each year between 2–3 million people in the United States experience an episode of homelessness (Caton et al., 2005). The psychological and physical impact of homelessness is a matter of public health concern (Schnazer, Dominguez, Shrout, & Caton, 2007). Psychologists as clinicians, researchers, educators, and advocates must expand and redouble their efforts to end homelessness.

The APA Presidential Task Force on Psychology’s Contribution to End Homelessness, commissioned by James Bray, PhD, during his tenure as APA's president, developed a mission to identify and address the psychosocial factors and conditions associated with homelessness and define the role of psychologists in ending homelessness.

HUD reported that 1.6 million people were without homes in 2008. In the United States, the overall population of people living without homes can be divided into several subgroups including individual adults, families with children, and unaccompanied youth who have left home, run away, or “aged out” of foster care placements.

Individual Adults

  • Most homeless adults live in shelters, on the streets, in settings not intended for habitation, or doubled up with friends or family members (US Conference of Mayors, 2009).

  • Men comprise 68% of sheltered adults, yet the number of women in this population is increasing (Lehman et al., 2007; U.S. HUD 2009a).

  • The vast majority of adults without housing are homeless on a short-term basis (Caton et al., 2005; Kuhn & Culhane,1998).

  • Studies report varying average length of shelter stays, but it is widely agreed that only 10% of adult populations meet criteria for chronic homelessness (Caton et al., 2005).


  • Veterans constitute 13% of all sheltered adults (U.S. HUD, 2009b).

  • A recent study showed a clear relationship between veterans with bipolar disorder, mental illness and both lifetime and recent homelessness (Copeland et al., 2009).

  • In one study, homelessness has also been associated with suicide among veterans with diminished social and environmental support (Lambert & Fowler, 1997).

Elder Adults

  • Adult population of people living without homes has grown older (Shinn et al., 2007).

  • Aging of homeless population has been linked to several factors, including overall aging of the U.S. population, limitation of subsidized housing for elders, and a loss in benefits or pensions (Crane et al., 2005; Dietz & Wright, 2005).

Incarcerated Adults

  • The rate of homelessness among the general U.S. population is estimated to be 1.36 - 2.03%, whereas the rate of recent homelessness among jail inmates is 15.3%. (Greenberg & Rosenheck, 2008).

  • As many as 1 out of every 6 incarcerations involves a person who was without housing at the time of arrest (McNiel, Binder, & Robinson, 2005).

  • Inmates who have recently lost housing are more likely to be incarcerated for property crimes, which may be a result of “survival behavior” (Greenberg & Rosenheck, 2008), and/or to be arrested for “nuisance offenses” such as camping without a permit (DeLisi, 2000).

  • Of inmates with mental illness who were also without housing, 78% had substance use problems; in addition, increased duration of incarceration is associated with homelessness and co-occurring serious mental illness and substance use disorders (McNiel et al., 2005).