Social networks and substance use among at-risk emerging adults living in disadvantaged urban areas in the southern United States: a cross-sectional naturalistic study.

BACKGROUND AND AIMS Substance use and risk-taking are common during emerging adulthood, a transitional period when peer influences often increase and family influences decrease. Investigating relationships between social network features and substance use can inform community-based prevention programs. This study investigated whether substance use among emerging adults living in disadvantaged urban areas was influenced by peer and family social network messages that variously encouraged and discouraged substance use. DESIGN Cross-sectional, naturalistic field study. SETTING AND PARTICIPANTS Lower-income neighborhoods in Birmingham, Alabama, USA with 344 participants (110 males, 234 females, ages 15-25 years; mean = 18.86 years), recruited via respondent-driven sampling. MEASUREMENTS During structured interviews conducted in community locations, the Alcohol, Smoking and Substance Involvement Screening Test assessed substance use and related problems. Predictor variables were network characteristics, including presence of substance-using peers, messages from friends and family members about substance use and network sources for health information. FINDINGS Higher substance involvement was associated with friend and family encouragement of use and having close peer network members who used substances (Ps < 0.001). Peer discouragement of substance use was associated with reduced risk (b = - 1.46, P < 0.05), whereas family discouragement had no protective association. CONCLUSIONS Social networks appear to be important in both promoting and preventing substance use in disadvantaged young adults in the United States.