Specifically, younger males who regarded themselves as regular users of ST, but were not smoking cigarettes, were three times more likely to be smoking cigarettes 4 years later in comparison with the same-aged individuals who were not using ST products (Tomar, 2003). Further, younger age of initiating ST use tends to be inversely related to abstinence 1 year after Sorafenib Tosylate cost bupropion sustained release treatment (Ebbert, Glover, Shinozaki, Schroeder, & Dale, 2008). Future studies with American Indians should assess for age of initiating ST use as this may be related to latter onset cigarette use, success of quit attempts, or responsiveness to cessation treatments. An examination of the psychiatric disorder prevalence rates revealed no differences between users and nonusers in regards to panic disorder, major depression, and PTSD in both tribes.
In contrast to cigarette smoking, substantially less research has investigated ST rates among individuals with anxiety and depressive disorders. Only a single study has reported higher rates of any 12-month anxiety disorder among individuals with current ST nicotine dependence (Goodwin et al., 2008). Rates of anxiety and depressive disorders are approximately 1.5�C3.0 times higher among smokers relative to nonsmokers (Johnson & Breslau, 2006; Wilhelm et al., 2006), with the prevalence of psychiatric disorders continuing to increase among those individuals who are nicotine dependent (Goodwin et al., 2008; Ziedonis et al., 2008). Perhaps, significant associations between ST with anxiety and depressive disorders only emerge among those who are nicotine dependent.
A further analysis of nicotine dependence among American Indians would appear warranted in order to assess this hypothesis and determine if findings of Goodwin et al. (2008) can be replicated. Lifetime alcohol use disorders were significantly more common among users relative to nonusers in both the Northern Plains and Southwest tribes. Among a sample of female military recruits, daily or near-daily alcohol consumption was significantly associated with an increased likelihood of ST use (Vander Weg et al., 2005). Although comparable studies investigating the ST�Calcohol link are limited, the high comorbidity between nicotine and alcohol use disorders has been well established. The majority of these studies have either examined cigarette smoking alone (Durazzo, Gazdzinski, & Meyerhoff, 2007; Jensen et al.
, 2003) or combined ST with all other forms of nicotine administration (Grant Brefeldin_A et al., 2004). Hence, future research may need to isolate ST from other forms of tobacco administration in an effort to better understand its unique association with alcohol use. Logistic regression analyses with each psychiatric disorder on lifetime ST risk revealed differential findings between the tribes.