injection drug user, HIV risk behaviors, social networks, network changes


Studies indicate that HIV risk behaviors vary greatly among injection drug users (IDUs). The source of such variation is often ascribed to individual differences, but much of it is due to how IDUs are grouped into social networks. Nevertheless, given the turbulent and uncertain lives led by many IDUs, it would not be surprising if their social networks changed substantially over time. We used data from a study of the social networks of IDUs in Chicago and Washington, DC, to examine changes in individual behavior and network characteristics over time. The results indicated few changes in standard network measures, such as density of ties or network size, over time. However, specific network change measures, that is, indicators of movement into and out of networks, showed significant movement of network members over time. Moreover, movement of members into a network significantly predicted a higher likelihood of risky injection drug use over time. We suggest that these movements are indicative of a lack of a stable resource base among IDU networks.

Original Publication Citation

Hoffmann, John P., S. Susan Su, and Alfred Pach. 1997. “Changes in Network Characteristics and HIV Risk Behavior among Injection Drug Users.” Drug and Alcohol Dependence 46(1-2):41-51.

Document Type

Peer-Reviewed Article

Publication Date


Permanent URL


Drug and Alcohol Dependence




Family, Home, and Social Sciences



University Standing at Time of Publication

Full Professor