With varied paths to the streets and unique individual experiences, homeless youth are not a homogeneous population.² Generally, they have disproportionately experienced poverty; early childhood loss (such as parental death or incarceration); family chaos (including parental substance abuse and domestic violence); mental illness; emotional, physical, and/or sexual abuse and/or neglect; and resulting foster care placement.¹,²,³,⁴,⁵,⁶

The actual size of the homeless youth population in the US is unknown. Estimates have ranged from 500,000 to 1.6 million.¹,⁴,⁷ Obstacles to an accurate count include variability in definitions of homelessness; considerable methodological challenges; the hidden and intermittent nature of youth homelessness; youths’ avoidance of services because of fear of authorities; and reluctance to identify as homeless due to stigma.⁸,⁹,¹⁰,¹¹

Youth homelessness is inconsistently defined in the medical literature and in federal legislation. The McKinney-Vento Homeless Education Assistance Act offers perhaps the most useful federal definition, defining homeless youth as those who lack “a fixed, regular, and adequate nighttime residence”.¹²

The literature employs multiple, overlapping terms. Runaways are minors who have left home and lack adult supervision, commonly because of family conflict, abuse, and/or neglect. Throwaways are minors who have been ejected from their home by their families, frequently because of poverty, conflict, or familial substance abuse. Couch surfers migrate from one unstable housing situation to another, often falling through the cracks to find themselves without any shelter. Literally homeless youth. live on streets or in parks with no access to housing. Street youth strongly identify with a local street-involved community of youth. Systems youth are youth who may become homeless after aging out of youth services, such as juvenile justice or foster care. We employ the term homeless youth for all these youth, recognizing that many youth would reject the label.²

In most locations, the majority of homeless youth come from the local community or nearby. Some large metropolitan areas in North America such as New York, Denver, Los Angeles, San Francisco, Seattle, and Vancouver serve as gathering places for homeless youth from broader regions. However, even in these locations, a large percentage of homeless youth come from the local community. Minors and youth who are disproportionately represented among the homeless include former systems youth; young adults recently released from prison or jail; veterans; lesbian, gay, and bisexual youth; transgender youth; immigrant and undocumented youth; and low-income ethnic minority youth, particularly African American, Latino, and Native American youth.⁴,¹³,¹⁴

Given their lack of familial support, society’s failure to provide for them, and their underlying vulnerability, homeless youth have limited options to meet their basic needs for food, shelter, safety, emotional support and health care. Although adolescence is a developmental stage during which experimentation and exploration are normative (see Chapter 3), homeless youth often engage in behaviors considered particularly risky by providers in order to meet their basic needs and to bond with peers. Although this may be seen as dangerous within a medical paradigm, these behaviors may be quite rational from the standpoint of survival. To reduce their risk, youth require alternative means to meet their needs.

Homeless youth are not only more likely than housed peers to have experienced trauma prior to being homeless, they are also at far greater risk than housed youth of experiencing additional episodes of violence, physical abuse, or sexual exploitation. In a multicity study of homeless youth, Bender and colleagues reported that 79% of youth recruited from homeless youth-serving agencies reported multiple types of childhood abuse and 29% reported street victimization.¹⁵ Lesbian, gay, bisexual, and transgender (LGBT) youth report particularly high rates of victimization.³,¹⁴,¹⁶ Youth may resist reporting or refuse services because of prior negative consequences resulting from reporting of past trauma (such as separation from family and removal from home), or because of economic dependence on a current abuser (such as a “pimp” or drug dealer). Providers should be guided by local laws and guidelines to ensure youth’s safety (see Chapter 9). Furthermore, for minors who are being sexually exploited, guidelines regarding trafficked youth also apply.¹⁷

Alcohol, tobacco, and other drug use and abuse are more prevalent among homeless youth than among housed youth. However, patterns of use vary greatly by geographic area. Injection drug use (IDU) is far more common among homeless youth than among housed youth and is a significant source of morbidity and mortality from overdose, addiction-related behaviors, drug effects, and blood-borne infections.¹⁸ Venue-based samples of homeless youth in both San Francisco and Vancouver yielded a prevalence of IDU of 40%.¹⁹,²⁰ Community-based naloxone distribution has been found to be a life-saving measure.²¹ Harm-reduction strategies that make clean syringes and drug-use paraphernalia available reduce the risk of negative consequences of IDU, including transmission of HIV/hepatitis C.²² Methamphetamine use is also prevalent among homeless youth in many cities, with youth in a longitudinal study in Vancouver reported to have a incidence of methamphetamine initiation of 12.2 per 100 person-years.²³