, 2007). The Brown et al. (2007) trial compared the effects of bupropion versus placebo and cognitive�Cbehavioral treatment for depression added to standard cognitive�Cbehavioral www.selleckchem.com/products/chir-99021-ct99021-hcl.html smoking cessation treatment versus standard cognitive�Cbehavioral smoking cessation treatment on 7-day point prevalence abstinence, at four timepoints, in a sample of 524 smokers. Using longitudinal analyses (Zeger & Liang, 1986), Brown et al. (2007) reported a significantly increased effect of bupropion on abstinence (OR = 1.97, p = .03), consistent with previously observed bupropion effect sizes. In addition, Brown et al. (2007) reported significant negative effects of cigarettes smoked per week, time, and a treatment by time interaction on abstinence, but no additional significant interactions of pharmacotherapy nor significant or interactive effects of behavioral therapy.

Brown et al. (2007) concluded that bupropion does not exhibit differential effects on abstinence among individuals with a history of depression or with elevated depressive symptoms, nor did specialized behavioral therapy for depression have significant effects on abstinence overall or among individuals with a depression history. The DRD4 Exon III VNTR is a 48-base-pair coding region sequence exhibiting polymorphism in the number (Van Tol et al., 1992) and in the sequence of repeated units (Lichter et al., 1993). Two-, four-, and seven-repeat alleles are the most prevalent alleles, where the prevalence differs by ancestry (Chang, Kidd, Livak, Pakstis, & Kidd, 1996).

In vitro evidence suggests that the seven-repeat receptor requires more dopamine to inhibit cyclic adenosine monophosphate (Asghari et al., 1995), and that the seven-repeat allele sequence suppresses transcription in engineered constructs (Schoots & Van Tol, 2003). The seven-repeat allele is somewhat less expressed in postmortem human brain samples (Simpson, Vetuz, Wilson, Brookes, & Kent, 2010). Haplotype and sequence analyses suggest that the seven-repeat allele has been subject to positive selection over the past 40- to 50,000 years (Ding et al., 2002; Wang et al., 2004). Leventhal et al. (2012) utilized a sample of 331 individuals from the Brown et al. (2007) trial who consented to genotyping and who self-identified as White, genotyped the VNTR, and grouped individuals by treatment and by genotype to evaluate the effect of predictors and covariates on abstinence at four timepoints.

Leventhal et al. (2012) utilized a dominant coding of alleles with seven or more 48-base-pair repeats and reported results from a series of unadjusted and adjusted longitudinal analyses. As expected (Brown et al., 2007), Leventhal et al. (2012) report significant effects of treatment (OR = 1.16, 95% CI: 1.07�C1.26, p = .0004) and time (OR = 0.91, 95% CI: 0.89�C0.92, p < .0001). They also Entinostat report a significant gene by treatment interaction (OR = 1.