The association between depression and smoking is firmly established, but how the association develops remains unclear. The aim of this study was to examine development of the smoking-depression association from early adolescence to adulthood.
Cross-sectional and longitudinal analyses of the smoking-depression association from adolescence to adulthood.
Hordaland, Norway.
A cohort of adolescents (initially, 924 pupils) in the Norwegian Longitudinal Health Behaviour Study (NLHB) was followed over nine data collection waves from ages 13 to 30 years.
Daily smoking and depressed mood were measured in each wave.
In the cross-sectional analyses, daily smoking and depression were significantly associated (P-value range from P?