Peer and neighborhood influences on substance use among emerging adult males: An activity spaces approac

Introduction: Alcohol and substance use are common among emerging adults and may result in negative outcomes such as unsafe sex and poor mental health. Males are more susceptible to problems with substances, and minority men may be at particular risk for developing problems with substance abuse. Peer influence and neighborhood level characteristics are two areas that are related to substance use behavior in this population. However, there is little work examining how social networks interact with other aspects of individuals' social contexts. Using an event-based approach utilizing routine locations individuals travel to (activity spaces) may help to elucidate these relationships.;Methods: Participants identified activity spaces for a typical week. Peer network quality and neighborhood level characteristics (including socioeconomic and built environment indicators) were measured for each activity space. Generalized estimating equations were used to examine associations between peer and neighborhood predictors for each activity space and alcohol and marijuana use. Activity spaces were characterized as risky or non-risky, and interaction terms for neighborhood characteristics by risky space were included to examine moderation by risky spaces. Results: Seventy emerging males identified 397 activity spaces. Lower network quality at activity spaces was associated with greater number of days of marijuana use (B=-0.0033, p<0.01), use of marijuana more than one time per day (B=-0.0183, p<0.01), and higher problem alcohol use (B=-0.0132, p <0.01). Greater number of police stations, alcohol outlets, and churches near activity spaces was related to greater marijuana use in risky spaces. Greater crime near risky spaces was related to more problem alcohol use.;Conclusions: Peer and geographic influences are important predictors of alcohol and marijuana use among emerging men. Importantly, these influences may differ for high risk versus low risk places. Our use of activity spaces nested within individuals expands the current literature examining these factors in relation to substance abuse.