e., Scatter and Shape). We hypothesize that profile Scatter will be

greater among ITS, because their intermittent smoking may reflect more specificity of motivation; that each ITS, perhaps idiosyncratically, will be driven PD-0332991 molecular weight by only a few motives but not others. In contrast, we expect DS to endorse many motives, which may help to explain why their smoking is so pervasive and resistant to change. Finally, our main hypotheses concern profile Shape – the relative importance of particular motives. Table 1 lists our hypotheses for which motives are likely to be more prominent in ITS vs. DS profiles, based on the expectation that motives tied closely to dependence will dominate DS profiles, while those more associated with specific,

situational motives, and with acute use, will dominate ITS profiles. In other words, DS are expected to show higher relative endorsement of PDM while ITS show higher relative endorsement of SDM. Using a similar approach, we previously found that chippers – who smoke at very low levels, though often daily – show a different profile from heavy smokers on questionnaires of smoking patterns and motives (Shiffman et al., 1994). Chippers emphasized social and sensory motives for smoking, whereas heavy smokers emphasized addiction and automaticity as motives. We expect similar CX 5461 patterns contrasting ITS and DS, but it is not clear whether non-daily smokers (ITS) studied at a time when such behavior is common, are similar to very light smokers (chippers) studied at a time when such behavior was very rare. ITS are a heterogeneous group. In particular, some ITS have never smoked daily (“native” ITS or NITS), while others have evolved to ITS from a history of having been daily smokers (“converted” ITS, or CITS;

Edwards et al., 2010, Nguyen and Zhu, 2009, Shiffman et al., 2012c and Tindle and Shiffman, 2011). CITS demonstrate greater dependence than NITS (Shiffman Methisazone et al., 2012b), including scores on the PDM and SDM subscales of the WISDM, but their profile of motives has not been compared. We expect that given their history of daily smoking, CITS will be more like DS, with flatter profiles (lower profile scatter), and profiles emphasizing dependence-related motives. Besides shedding light on ITS’ smoking motives, and differences between CITS and NITS, the present analyses can help validate the WISDM, and particularly the distinction between PDM and SDM. Since ITS are expected to be less motivated by classical dependence motives, the study represents a known-groups validation design. Observing that specific motives associated with PDM are relatively lower in ITS, and specific motives associated with SDM relatively higher in ITS, would help validate the WISDM constructs. Participants were volunteers recruited via media to participate in a non-cessation study on smoking patterns.