, 2010). Notably, however, smoke intake responses to mood tended to run in opposing 17-DMAG 467214-21-7 directions when we combined the factors of DTS and subject sex. The interaction of DTS by mood on smoke intake (puff volume and number) was significant for men and for women but in contrasting manner. While lower distress tolerance in men was related to greater smoke intake during negative mood and not neutral mood, generally the opposite interaction was observed in women. For women, lower distress tolerance was related to greater puff volume (marginally) and puff number (significantly) during neutral mood and not at all related during negative mood. One potential implication of these results is that distress tolerance and subject sex do not combine in additive fashion to increase smoking responses to negative mood.

An explanation for this pattern of sex differences in the way distress tolerance influences smoking responses to mood is not obvious, particularly since the increase in smoke intake due to negative mood was significantly greater in women compared with men, collapsing across DTS (bottom of Figure 1). Women lower in distress tolerance may be more likely to smoke maximally during either mood condition when given the opportunity (i.e., ��ceiling effect��). If so, a further increase in smoking due to negative mood might be difficult within a prescribed period of time (e.g., the 14-min ad libitum smoking period of this study). By comparison, women higher in distress tolerance may generally smoke less during neutral mood, allowing greater opportunity to increase smoke intake during the negative mood condition (see bottom of Figure 2).

Further research should examine different intensities of negative mood induction, as well as different types and durations of induction procedures, to determine whether the sex difference in effects of distress tolerance on smoking may depend on severity or type of negative mood induction and the duration of smoking access. Regarding the different assessments of distress tolerance, we found no effects of distress tolerance as measured by the behavioral tasks of mirror-tracing and breath-holding duration compared with some smoking intake results for men and women assessed by the DTS self-report measure of distress tolerance. In addition, although breath-holding duration was correlated with mirror-tracing and self-reported DTS score, DTS and mirror tracing were not significantly correlated, Drug_discovery confirming a clear difference between self-report and some task measures of distress tolerance (McHugh et al., 2011).