Only being a past 30-day CCLC user was uniquely associated with concurrent use of smokeless tobacco, depression, anxiety, and antisocial behavior (p��s for cigarette use >.17; p��s for CCLC use <.04). Past 30-day CCLC use was not uniquely associated with number of cigarettes smoked on smoking days in the past month, and both indices of nicotine dependence SAHA HDAC (p��s > .10). However, frequency of cigarette use was uniquely associated with these cigarette-specific variables (p��s < .0001) DISCUSSION Results from the current investigation suggest that CCLC use is common among American high school students who currently smoke cigarettes, and that this co-use may represent an important public health phenomenon.

We observed rates that were much higher than rates in the general adolescent population (CDC, 2012), which is not surprising as we restricted our sample to current cigarette users. Demographic between-group differences were largely consistent with previous reports (CDC, 2012; Cullen et al., 2011); males in our sample had a higher likelihood than females of being a CCLC ever and past 30-day user and also comprised a higher proportion of both CCLC using groups than non using groups. Yet, females still represented a significant proportion of the CCLC use in this sample. Additionally, similar to other investigations (CDC, 2012), our analyses did not reveal any differences in use across other demographic distinctions (including race/ethnicity), with the exception of lower levels of academic achievement among past 30-day CCLC users compared with nonusers.

Individuals who used both CCLC and cigarettes tended to exhibit more remarkable tobacco and other substance use profiles than non-CCLC users. Importantly, many of these relationships persisted even after accounting for frequency of cigarette use. CCLC users in our sample reported a higher rate of concurrent use of other tobacco products including smokeless tobacco, bidis, kreteks, and hookah than nonusers. Interestingly, our finding that concurrent use of hookah continued to be associated with CCLC use even after accounting for all other variables closely mirrors other work done with this sample; Sterling and Mermelstein (2011) found that CCLC use, and not use of other tobacco forms, was predictive of past 30-day hookah use in a multivariate logistic regression model.

Additionally, data from the current investigation replicated findings by Cullen et al. (2011), showing that CCLC users were more likely than non users to have smoked marijuana. Finally, our data indicated that CCLC use was related to increased rates of experimentation with several other illicit drugs of abuse, higher Drug_discovery rates of recent alcohol use, and elevated levels of alcohol-associated problems. Although our results cannot clarify the temporal ordering of behaviors, these data do show that cigarette smokers who have some history of CCLC use are vulnerable to a wide constellation of substance use behaviors.