Illicit drug use in one's social network and in one's neighborhood predicts individual heroin and cocaine use

PURPOSE: The nature of competing social environmental factors' influence on substance abuse is unclear. A longitudinal study was undertaken to determi ne the relative power of social network and neighborhood characteristics to predict continuing illicit drug use. METHODS: Three hundred forty-two inner-city adults with a history of inject ion drug use were followed for I year; their heroin and cocaine use were as sessed semiannually. Multiple logistic regression models were fit to determ ine the degree to which social network and neighborhood characteristics, as sessed at baseline, predicted continuing heroin and/or cocaine use througho ut the study period. RESULTS: Two hundred thirty-six (69%) participants reported continuing hero in and/or cocaine use. Drug use by members of the social network was a stro nger predictor of participants' continuing drug use (OR = 4.31, 95% Cl 2.51 to 7.40) than was a high level of drug-related arrests in the participant' s neighborhood (OR = 2.41, 95% Cl 1.24 to 4.71) after adjusting for drug tr eatment and demographic variables. Both seemed to have independent effects on study participants' drug use. CONCLUSIONS: These findings reiterate the importance of breaking ties with drug-using associates, even for those who reside in high-risk environments. Further work is needed to develop interventions that increase drug users' success in altering social network composition or also treat drug-using net work members. (C) 2001 Elsevier Science Inc. All rights reserved.