Risk and Resilience Factors for Youth Homelessness in Western Countries: A Systematic Review

Given the focus of this review on primary prevention, our definition of homelessness was designed to be as inclusive as possible to capture all persons who lack stable and safe housing and followed the definition given by the McKinney-Vento Homeless Assistance Act of 1987. This legislation defined homeless persons as those lacking a fixed, regular, and adequate nighttime residence or having a nighttime residence that is a publicly or privately operated shelter, a public or private place that provides temporary residence for those intended to be institutionalized, or a public or private place not designed for use as a regular sleeping accommodation for human beings (9). Our definition also included those exiting an institution—e.g., jail or a hospital—where they resided temporarily (who were in a shelter or place not meant for human habitation immediately prior to entering that institution); those living in overcrowded or temporary residences; those who “couch surf” or live with various friends or family members because they do not have a permanent residence (10); those experiencing frequent moves (two or more in the past 60 days); those experiencing continued difficulties maintaining housing because of disability, domestic violence, or employment barriers; and those at imminent risk of homelessness (persons forced to leave their current housing within the next 14 days, who would subsequently be left without a place to go or resources to get housing).

In the literature, homelessness is also differentiated as an acute or chronic experience. Homelessness is a transient state, and most people will experience only short-term or acute homelessness (11). Chronic homelessness is typically defined as being continuously homeless for more than 1 year or having experienced four or more episodes of homelessness in the past 3 years (12).

A systematic review was completed of quantitative research articles examining risk and resilience factors for homelessness among youths. For this review, we performed a standardized search of abstracts in PubMed (1950–2019), and PsycINFO (1974–2019) databases on January 23, 2020. Search terms included risk AND/or resilience AND homelessness AND/or homeless AND youth AND/or young AND/or child AND/or adolescent in abstracts or titles. The PubMed search resulted in 543 abstracts, and the PsycINFO search resulted in 611 results (see online supplement to this article for further details). Thus the initial search yielded 1,154 articles, including 492 duplicates that were removed. Three additional articles were identified through reference lists and by speaking with field experts. The inclusion criteria were that the article was published in English and peer reviewed, it reported on a quantitative examination of risk or resilience factors for homelessness among young people (ages 0–25), and the study had an adequate comparison group (e.g., nonhomeless). Articles examining participants from non-Western countries were excluded, because there were not enough studies in this area to focus on system-level differences between Western and non-Western societies. Articles were also excluded if the factors examined occurred only subsequent to homeless experiences (i.e., if the study did not measure any factors occurring prior to homelessness episodes). After article abstracts were screened with the inclusion and exclusion criteria, 38 articles remained. The full texts of these articles were screened for the inclusion criteria, which left 16 articles for these analyses. During full-text screening, articles were primarily excluded because the study lacked an adequate comparison group or examined only factors subsequent to homelessness.

The rigor of each study was evaluated by using the Quality Assessment Tool for Observational Cohort and Cross-sectional Studies (www.nhlbi.nih.gov/health-topics/study-quality-assessment-tools), which considers study design, item measurement, selection bias, and detection bias. Risk or resilience factors were extracted from the articles by two independent reviewers (REG, VLT). These factors were defined as any dependent variable for which an association with homelessness was measured in the analyses. Factors that were associated with increased risk of homelessness were considered risk factors, and factors associated with decreased risk of homelessness were considered protective factors. Any disagreements were discussed, and a consensus reached. If it was not possible to extract the data from the publication, the authors were contacted for clarification.

This review indicated that a number of individual and family risk factors place young people at higher risk of becoming homeless. Risk factors for homelessness in the general population identified in the review appeared to fall into six main categories: family-related factors (e.g., single-parent household and family conflict); mental health, behavioral, or substance use; a history of trauma; school or academic issues; housing instability as a child; and a history of homelessness or running away. Protective factors were not as commonly examined, but factors identified in the general population included having a supportive and high-functioning family, higher SES, and educational attainment. Family connection was important across all populations studied. In terms of demographic factors, being of Hispanic ethnicity was protective, whereas being non-White was a risk factor. The factors that led to the largest odds of homelessness included a history of running away (17, 24), being in foster care (17), and being from a single-parent family (26). These factors appeared to differ somewhat from risk factors for homelessness as an adult (31), with the family playing a much more important role.

Importantly, most risk factors reported by each study were found to be independent of each other (2, 15, 16, 19, 23, 24, 26). Of interest, household income was a risk factor that was independent of high school completion, because these risk factors were significant when the analysis controlled for the other factor (2). Mental health difficulties and substance use were also independent risk factors (24), as were economic difficulties and mental health problems (24). Family violence, placement outside the home, a poor parent-child relationship, and behavioral disorders also all independently predicted homelessness (19).

This review has highlighted the current state of research on factors affecting homeless experiences of youths and has identified gaps in our knowledge. The limited scope of currently available research presented a significant challenge for this systematic review. First, the research on specific populations was limited, affecting the ability to determine whether risk factors differ across sample types (e.g., foster care populations, youth accessing homelessness services, youth justice populations, and sexual minority populations). Additionally, certain populations, such as youths with serious mental illnesses, were not examined specifically by any study. Given the high rates of homelessness in the population with serious mental illnesses and given that homelessness interferes with recovery from mental illness (32), it seems vital to examine specific risk and protective factors related to homelessness for individuals affected by mental health conditions. However, excluding factors particular to specific samples (e.g., number of foster care placements for youths in the foster care system), all categories of risk highlighted by this review were present in large-scale general population studies, in addition to being found in other specific populations. This implies that the risk factors identified here contribute to homelessness more broadly and across a range of risk groups.

Second, research on protective factors was limited. Only ten of the 16 articles examined protective factors, and the protective factors were often very specific and were not examined in more than one study. Consequently, this review was able to identify only themes of protective factors present across multiple studies, including connection to family and academic or occupational achievement. Examining resilience factors is challenging, because it is difficult to identify populations that are at risk of homelessness but that manage to remain housed. Following high-risk populations, such as LGBTIQ+ (lesbian, gay, bisexual, trans, intersex, and queer) youths or youths experiencing severe mental illness and measuring housing instability as well as possible resilience factors across shorter periods might allow a more nuanced understanding of factors that reduce the likelihood of becoming homeless.

A more comprehensive model of resilience factors would facilitate development of a primary prevention strategy. For example, we know that a youth’s connectedness to his or her family and parents is a protective factor. Parents who are more responsive to their child promote development of strong self-regulation skills, which are protective against becoming homeless (3). Such protective factors represent potential elements to incorporate into prevention efforts—for example, through family-focused interventions. Other preventive efforts could identify youths whose family may not have the capacity to participate in interventions and provide programs that support them to develop other natural support networks and build on resilience factors (e.g., by supporting them to stay in school and develop financial independence).

Third, among the articles reviewed, there was little or no research examining community- and system-level factors, such as social policy, job availability, or housing availability, and their role in homelessness. Individual and family factors are clearly important to consider for homelessness, because these can often be targeted more easily by organizations aiming to prevent homelessness. For example, case managers can help individuals to build relationships with their family, get a job, and access support for mental health or substance use difficulties. However, without addressing broader community-level problems that contribute to homelessness, such as low wages or lack of affordable housing, which may be affected by systemic racism, this may be akin to swimming against the current. Because of the lack of literature examining individual factors in the context of community-level factors, it is difficult to know what role the wider societal environment plays in youth homelessness. This distinction has important policy implications, because risk would likely vary depending on what supports or safeguards against homelessness are available from the government. It would be interesting to understand how housing availability affects young people and whether current primary prevention interventions, such as rapid rehousing, are effective for youth populations. Rapid rehousing provides homeless individuals and families with short-term assistance to pay rent and with support for a quick transition into permanent housing. Further projects should aim to examine risks for youth homelessness within a more comprehensive framework.

Finally, the research examined in this review focused overwhelmingly on individual homelessness, rather than on youths who experience homelessness as part of the family unit. Family homelessness is primarily associated with parental difficulties (33), whereas individual homelessness as discussed in this review is primarily related to difficulties that the young person is experiencing individually as well as in relation to his or her family. However, it is unclear what risk or resilience factors might be common across the two situations. It is also important to understand how the experience of family homelessness by a young child may contribute to a later risk of homelessness as an adult. For example, because a history of homelessness predicts future homelessness, interventions targeting homeless families to support a quicker transition to housing may reduce later homelessness for children when they become young adults. Because homeless families account for 35% of the total homeless population, this is an important consideration (34). To comprehensively inform policy and develop effective primary prevention for youth homelessness, these issues need to be addressed by future research.

To summarize the current state of the literature, promote future research addressing these knowledge gaps, and provide a framework for clinicians to integrate into service delivery, a provisional model summarizing the current knowledge base of the risk and resilience factors for youth homelessness is described below (also see figure in online supplement). Where appropriate, we also integrate other known homelessness risk research that did not meet criteria for our review, to best capture the full cycle of youth homelessness. This model aims to assist in the generation of primary prevention interventions by indicating where known risk and protective factors may be important to consider in the pathway toward youth homelessness.

Known distal risk factors can occur throughout the development of homelessness risk (see figure in online supplement). These factors include individual, family, and community risk factors as discussed above. In addition, the model also includes known proximal risk factors. Because homelessness is a dynamic state, consideration of more proximal risk factors is vital. This includes risk factors discussed above that could be immediate triggers for running away or an initial homelessness episode, such as changes in mental health (25); increases in substance use (1); housing transitions, such as exiting foster care (15, 16); leaving a psychiatric stay (20); or family conflict (26). Seventy percent of homeless youths cite family conflict as the reason for their homelessness (35), which suggests that feeling disconnected from family or being forced to leave is a key reason that youths leave home. As discussed above, it is difficult to disentangle the impact of past homelessness on these risk factors, which should be addressed in future research.

Young persons’ resilience factors and resources can also act to protect them against both distal and proximal risk factors. Known protective factors include high SES (23), employment (24), family support and involvement (26), good family relationships (22), and school achievement (1, 24). These factors may indicate that, despite risks, a young person who is given support in these domains is less likely to end up homeless.

Also discussed in the reviewed literature and included in the model are factors that may support exiting homelessness or prevent entering a more chronic homelessness cycle. For example, if young people who have run away from home or are experiencing acute homelessness are able to access services (15) or family support (1), they may be able to become housed again. Additional studies of youths that did not fit review criteria suggest that those with feelings of personal control appear more resilient and able to exit homelessness (36). For some young people, becoming homeless and then housed again turns into a repetitive cycle (37). For young people who experience long-term substance use difficulties (24), have difficulty accessing services (38), or have severe mental health problems (24), this cycle may lead to chronic homelessness.

Complex public health issues such as homelessness are difficult to address because they often require broad, multifaceted interventions to manage the variety of factors involved. Similar public health issues, such as suicide prevention, have been addressed by the World Health Organization (WHO). WHO suggests key components of a comprehensive and multifaceted prevention strategy, which include clear goals or objectives so that progress can be measured; identification of relevant risk and protective factors; effective interventions based on these risk and protective measures; prevention strategies at the general population level, vulnerable group level, and individual level; research on interventions and prevention strategies; and monitoring and evaluation of outcomes (39).

In applying this model to research on youths experiencing homelessness, we suggest similar objectives and intervention strategies, including increasing awareness of risk factors for homelessness (factors that occur at population, family, and individual levels), understanding and preventing risk factors for homelessness, improving research on homelessness risk and outcomes, and improving services that enhance housing outcomes for those who are at risk of homelessness, with an overall goal of reducing incidence of new homelessness. Additionally, it is important to consider that homelessness risk differs from suicide risk in that suicide prevention is not as directly dependent on policy-related factors, such as affordable housing, economic status, and governmental support and subsidies. Thus there are more system-level variables in homelessness prevention, and these will also need to be addressed by interventions.

Despite the need for further research, the model highlights several ideal targets for existing interventions for youths and may also assist in the development of new interventions (see figure in online supplement). The Upstream program, under development by University of Chicago researchers at Chapin Hall, is a primary prevention initiative involving screening youths at schools to identify those at risk of homelessness or school dropout and then providing supportive interventions. This example highlights the methods by which we can identify and address such risk factors before young people’s situations escalate to crisis (40). Another example of current state-level interventions targeting these risk factors includes state funding for housing supports for youths exiting the foster care system or extension of foster care beyond age 18. There is evidence that these strategies result in decreased odds of homelessness, which supports the idea that targeting these risk factors is effective (18, 41). Future research should examine whether these current strategies are targeting the most prominent risk factors for young people and whether changes can be made to better target key risk factors for youth homelessness, such as family conflict.

Although these strategies offer hope, many current interventions do not comprehensively address the distal risk factors that put youths at higher risk of homelessness, which highlights a need for further development of services. For example, support services for LGBTIQ+ youths should focus on community integration and support network development, whether networks involve youths’ families or a wider community service; family interventions aimed at increasing positive involvement and reducing conflict; and targeted services for children who are missing school or showing problem behaviors at school. Other areas for possible research and development include services that support individuals to navigate the system and access funding assistance or affordable housing and state-level interventions that would affect service availability, affordable housing availability, and governmental assistance.

A second area of focus for interventions is proximal risk factors, such as targeting youths who are at imminent risk of running away or homelessness. This review has identified important factors that could be targeted by current systems of care—for example, by training medical, substance use, and metal health providers to assess for and intervene in homelessness risk and by integrating social services for housing support into preexisting infrastructure, such as the current health care system. A third intervention point is for youths who have run away from home or who are experiencing acute homelessness. These interventions may need to target youth drop-in centers or identify youths on the streets and could include increasing service availability and assisting youths to feel more comfortable accessing services, reintegrating youths with their families and supporting families to reach out, encouraging a sense of control and resiliency among young persons, and supporting these youths to access substance use and mental health interventions. Interventions at this final point may be able to prevent a more chronic homelessness cycle.

However, primary preventive efforts require identification of adolescents who are at risk of homelessness (26). Although this review has identified distal and proximal risk factors, it is unclear whether a combination of these factors can be used in a meaningful way to predict those at highest risk. We propose using current knowledge of risk factors through a homelessness risk monitoring system. This can provide a framework for researchers to prospectively follow youths and examine the predictive power of these factors and for current health care or mental health care providers to provide targeted supports to young people at risk. Currently, there is no clear evidence-based way for youth services (such as mental health care, hospitals, and other social support systems, such as LGBTIQ+ services) to monitor and prevent homelessness. We propose a novel approach to monitoring these young people in clinical settings, the two-step Homelessness Outreach and Monitoring of Environments for young people or HOME assessment (see online supplement). This provides a flexible, actionable method of integrating the current knowledge of risk factors for youth homelessness into current youth services. Although HOME is based on the risk factors highlighted in this review, further research is now needed to examine the selection of risk factors, alongside this monitoring approach, and to validate whether this combination of risk factors is clinically informative and whether use of this monitoring and outreach approach reduces the incidence of homelessness among young people. In addition, we hope to expand HOME as more research is completed to better understand family and community risk alongside additional resilience factors.