Nicotine Dependence, Co-Occurring Substance Use Disorders, and Psychiatric Comorbidity

"It is estimated that nearly one-half of all cigarettes sold in the United States (44 percent) are consumed by people with mental illnesses or substance abuse disorders. In addition, the prevalence of tobacco use among those with either addictions and/or mental illness is between 38 to 98 percent, as opposed to 19.8 percent for the general population (Schroeder 2009). Breslau and colleagues (1991) have conducted several studies. One earlier population-based study in Michigan observed that young adults with a diagnosis of nicotine dependence reported higher prevalence of alcohol and drug dependence and major depression and anxiety disorders than did persons who had never experienced nicotine dependence (Breslau et al. 1991). The relationships between each disorder and nicotine dependence were observed even when adjustments were made for confounding comorbidities. These findings are similar to those observed for adolescent smokers described earlier (Dierker et al. 2001) (see 'Determinants of Nicotine Addiction' earlier in this chapter). However, the results were contrary to other findings among adolescents (Clark and Cornelius 2004; Rohde et al. 2004). Other population-based research and clinical studies have also pointed to the strong relationship between daily smokers or nicotine-dependent smokers (as opposed to lifetime nonsmokers or non-dependent smokers) and substance use disorders, anxiety disorders, and depression, with higher prevalence of comorbid psychiatric disorders among nicotine-dependent smokers and higher prevalence of nicotine-dependent smokers among persons with comorbid disorders. For example, in a U.S. population-based survey, Grant and colleagues (2004) observed that the prevalence of alcohol use disorders, current mood disorders, or current anxiety disorders among adult respondents with diagnoses of nicotine dependence during the past year ranged from 21 to 23 percent compared with 9 to 11 percent in the general population. Conversely, other studies have shown the percentage of persons with nicotine dependence among respondents with these comorbid disorders ranging from 25 to 35 percent and as high as 52 percent among respondents with drug use disorders compared with 12.8 percent in the general population (Glassman et al. 1990; Breslau et al. 1994, 2004b; Lasser et al. 2000; Degenhardt and Hall 2001; Kandel et al. 2001; Isensee et al. 2003; Schmitz et al. 2003; Grant et al. 2004; John et al. 2004)."