The current study sought to examine the direction of influences on longitudinal associations between anxiety sensitivity, anxiety and depression. The continuity of genetic and environmental influences on these traits over adolescence was also investigated. Self reports of anxiety sensitivity, anxiety and depression were collected from approximately 1,300 twin and sibling pairs, on two occasions (mean ages 15 and 17). The direction and etiology of the associations between these traits were examined using longitudinal genetic cross-lagged models. All traits were stable over time and this stability accounted for the largest proportion of variance at time 2. There was, however, also evidence of reciprocal associations between variables over time. Genetic effects were fairly stable across time, although new genetic influences were evident at the second time point. Environmental effects tended to be more time specific. This study adds to our understanding of the direction of effects between anxiety sensitivity, anxiety and depression in adolescence, and the risks underlying their associations.