Depressive symptoms, drug network, and their synergistic effect on needle-sharing behavior among street injection drug users

In this study, we examined the relationship between depressive symptoms and needle-sharing behavior in a community sample of intravenous drug users (N = 499) in Baltimore, Maryland. Based on the polytomous logistic regression , higher depressive symptoms were positively associated both with needle sh aring after cleaning with bleach and with needle sharing without first clea ning with bleach at the bivariate analyses. This relationship remained sign ificant (OR = 1.66) even after adjusting for demographic characteristics, l ife events, drug use patterns, and social and drug networks. A significant synergistic effect of depressive symptoms and drug network on needle sharin g after cleaning with bleach and needle sharing without cleaning was observ ed. More depressed intravenous drag users who also had a larger drug networ k were found to be at higher risk of needle sharing after cleaning with ble ach, as well as needle sharing without cleaning (OR = 2.59). Depression sta tus is discussed as a predisposing factor and drug network size as a precip itating factor for needle-sharing behavior. Implications for preventing nee dle-sharing behavior by reducing depressive symptoms are discussed.