Sociometric network structure and its association with methamphetamine use norms among homeless youth

• Examines the association between sociometric network norms and methamphetamine use.
• Examines the role of sociometric network structure in influencing perception of peer norms around methamphetamine use.
• Employs novel sociometric network method to sample two interconnected samples of homeless youth.
• Finds that perceived norms are significantly associated with self-reported methamphetamine use.
• Findings also indicate a strong association between cohesion and perception of norms.

Homeless youths' social networks are consistently linked with their substance use. Social networks influence behavior through several mechanisms, especially social norms. This study used sociometric analyses to understand whether social norms of drug use behaviors are clustered in network structures and whether these perceived norms (descriptive and injunctive) influence youths' drug use behaviors. An event-based approach was used to delineate boundaries of the two sociometric networks of homeless youth, one in Los Angeles, CA (n = 160) and the other in Santa Monica, CA (n = 130). Network characteristics included centrality (i.e., popularity) and cohesiveness (location in dense subnetworks). The primary outcome was recent methamphetamine use. Results revealed that both descriptive and injunctive norms influenced methamphetamine use. Network cohesion was found to be associated with perception of both descriptive and injunctive norms in both networks, however in opposite directions. Network interventions therefore might be effective if designed to capitalize on social influence that naturally occurs in cohesive parts of networks.