A recent study by Ramo and Prochaska (2012) examined past-month marijuana use, as well as the co-use of marijuana and tobacco, among young adult smokers in a national US sample. More than half (53%) of their sample reported past month marijuana use, with a median use of 18 out of the past 30 days. Further, co-use of tobacco and marijuana occurred on nearly half (46%) of the days on which either substance was used, and was more frequent among daily versus nondaily smokers. The authors conclude that cessation treatments for young adult smokers should broaden intervention targets to include marijuana.
Ramo DE and Prochaska JJ. Prevalence and co-use of marijuana among young adult cigarette smokers: An anonymous online national survey. Addiction Science & Clinical Practice 2012,7:5 (abstract)