the relation between smokingspecific parenting and smoking trajectories of adolescents how are changes in parenting related to changes in smoking in this study we tested to what extent smokingspecific parenting and changes in parenting are related to adolescents smoking trajectories data were used from a fourwave prospective study including 428 adolescents aged m 152 sd 060 latent class growth analyses were conducted to identify trajectories multinomial logistic regression analyses were executed to examine the relations between parenting and class membership longitudinal crosslagged models were tested to examine causal predominance between parenting and smoking four trajectories were found consisting of nonsmokers increasers stable smokers and decreasers quality of parental smokingspecific communication was strongly related to the membership in different trajectories along with the crosslagged associations demonstrating that the quality of communication was predominantly related to future smoking rather than vice versa these findings indicate that parents who talked about smoking in a constructive and respectful manner were more likely to have nonsmoking children in contrast parents who talked often about smokingrelated issues and increased these discussions over time were more likely to have smoking children crosslagged associations indicated that these findings could be best explained by children changing their parents having a nonsmoking agreement was related to a lower risk in becoming a regular smoker