Depression and nicotine dependence from adolescence to young adulthood

Abstract Introduction Despite the highly replicated relationship between depression and nicotine dependence, little is known about this association across both time and levels of lifetime smoking exposure. In the present study, we evaluate if symptoms of depression are associated with emerging nicotine dependence after accounting for smoking exposure and whether this relationship varies from adolescence to young adulthood and across increasing levels of smoking. Patients and methods The sample was drawn from the Social and Emotional Contexts of Adolescent Smoking Patterns Study which measured smoking, nicotine dependence and depression over 6 assessment waves spanning 6 years. Analyses were based on repeated assessment of 941 participants reporting any smoking 30 days prior to individual assessment waves. Mixed-effects regression models were estimated to examine potential time and smoking exposure varying effects in the association between depression and nicotine dependence. Results Inter-individual differences in mean levels of depression and within subject changes in depression from adolescence to young adulthood were each significantly associated with nicotine dependence symptoms over and above lifetime smoking exposure. This association was consistent across both time and increasing levels of lifetime smoking. Discussion Depression is a consistent risk factor for nicotine dependence over and above exposure to cigarettes and this association can be demonstrated from the earliest experiences with smoking in adolescents through the establishment of more regular smoking patterns across the transition to young adulthood. Conclusion Depression remains a prominent risk factor for nicotine dependence, and youth with depression symptoms represent an important subgroup in need of targeted smoking intervention.