Youth experiencing homelessness are a vulnerable population with increased behavioural health risks. Social networks are a consistent correlate of youths' substance use behaviours. However, less is known about the reciprocal relationships among these constructs. This study classified youth experiencing homelessness according to their social support network type (e.g. instrumental, emotional, service) and composition (e.g. family, peers, service staff) and linked their membership in these social network classes to sociodemographic and substance use characteristics. Four waves of cross-sectional data were collected between October 2011 and June 2013 from youth experiencing homelessness, ages 14-29, at three drop-in centres in Los Angeles, CA (N = 1,046). This study employed latent class analysis to identify subgroups of youth experiencing homelessness according to the type and composition of their social support networks. Multinomial logistic regression analyses were then conducted to identify the sociodemographic and substance use characteristics associated with social support network class membership. Five latent classes of youths' social support networks were identified: (a) high staff emotional and service support;(b) high home-based peer and family emotional, service and instrumental support;(c) moderate street-and home-based peer emotional support; (d) low or no support and (e) high home-based peer and family emotional and instrumental support.Multinomial logistic regression models indicated that race/ethnicity, gender, sexual orientation, literal homelessness, former foster care experience, depression, heroin and marijuana use were significant correlates of social support network class membership. Results indicate distinct classes of social support networks among youth experiencing homelessness, with certain sociodemographic and substance use characteristics implicated in youths' social networks.
K E Y W O R D Shomeless, relationships, risk factors, social networks, social support, substance use, youth