With few exceptions (Okoli et al., 2008; Alexander et al., 1999), studies rarely distinguish between having had a puff and having had one or more cigarettes and data are generally missing on interim levels of progression from a puffs to first cigarette or to regular smoking. Even less is known about the progression of trying a puff or taste of cannabis to more regular experimentation. Closely assessing initial tobacco or cannabis use could help to both characterize the progression of substance use across substances as well as help to determine variables key to such progression.
