Longitudinal associations between susceptibility to tobacco use and the onset of other substances among U.S. youth.

We examined whether tobacco susceptibility at Wave (W) 1 (2013-2014) predicts the onset of tobacco and other substances at W2 (2014-2015) among 5325 U.S. youth (12-17 years) never substance users at W1 in the Population Assessment of Tobacco and Health (PATH) Study.