Familial and non-familial smoking: effects on smoking and nicotine dependence.

BACKGROUND: This study examined the relative impact of familial and non-familial smoking on participant smoking and nicotine dependence.
METHODS: This is a longitudinal study of 838 African American and Puerto Rican participants who were interviewed four times in their homes over a 15-16-year period (1990, 1994-1996, 2000-2001, and 2004-2006).
RESULTS: Parental smoking during adolescence had a direct positive path to peer smoking during adolescence, which in turn had a direct positive path to participant smoking during the mid-twenties. In addition to the direct path between participant smoking in the mid-twenties and participant nicotine dependence during the late twenties, there was an indirect effect mediated by the partner's problems resulting from smoking during the late twenties.
CONCLUSIONS: This research demonstrates the key role the social environment plays in smoking and nicotine dependence. Both familial and non-familial smoking were significantly related to smoking and nicotine dependence. Public health implications suggest the importance of targeting prevention and treatment policies based on the participants' stage of development. During adolescence the focus should be on parental and peer smoking, whereas during the twenties attention might be paid to their own smoking and that of their partners.