Mental disorders and smoking trajectories: a 10-year prospective study among adolescents and young adults in the community.

BACKGROUND: Numerous studies have documented an association between mental disorders and onset of cigarette smoking. Yet, there is little understanding of the potential impact of mental disorders on trajectories of smoking over time. The objective of this study was to investigate this relationship among adolescents over a 10-year span.
METHODS: Data were drawn from the Early Developmental Stages of Psychopathology Study, a 10-year prospective investigation of youth in Germany. Growth mixture modeling was used to identify smoking trajectories and logistic regression analyses were used to examine relationships between mental disorders and subsequent trajectories.
RESULTS: Four trajectories were identified: non-users; increasing use; decreasing use; persistent use. Alcohol/drug use disorders, stress disorders, anxiety disorders, somatoform disorder and nicotine dependence were associated with nicotine use (as compared to the non-smoker class). However, comparisons between trajectories of nicotine use showed that any stress disorder predicted only decreasing use compared to the other two trajectories; nicotine dependence, alcohol/illicit drug use disorders as well as panic disorder and somatoform disorders were inversely associated with increasing use; nicotine dependence and alcohol/drug use disorders were associated with persistent use.
CONCLUSIONS: Several mental disorders appear to be non-specific markers of the range of smoking trajectories while others predict specific trajectories. Numerous disorders (e.g., alcohol/drug use disorders) do not appear to occur only prior to and predict increased smoking trajectory as had been previously suggested, but rather they also occur concurrently, with high levels of smoking and in some cases smoking persists at a steady level over time.