). Taken together, existing data raise the possibility that the TaqIA variants may be more http://www.selleckchem.com/products/ABT-888.html closely related to some specific aspects rather than broadly defined phenotypes of smoking behavior. Despite the extensive data on the association of TaqIA variants with DRD2 receptor densities and on the important role of the mesolimbic DA system in nicotine addiction, little research has been conducted to examine the involvement of this polymorphism in motivation to smoke, which is crucial to a fuller understanding of how this genetic factor contributes to nicotine addiction and individual response to treatments. A recent study indicates that smokers with A1 allele experienced greater ��liking�� for cigarette smoking, had shorter latency to first puff, and took more puffs under experimentally induced negative mood as compared with positive mood, while non-A1 carriers did not exhibit such behavior patterns (Perkins et al.

, 2008). It remains unknown whether this genetic variance contributes to other aspects of smoking motivation, in particular during abstinence. Craving has been posited as one of the motivational factors for smokers to maintain smoking behavior and for former smokers to lapse/relapse after abstinence (Killen & Fotmann, 1997; Shiffman et al., 1997). It is generally agreed among researchers that craving, under certain conditions, is directly related to relapse (Drummond, 2001). Besides craving, reasons for smoking are another reflection of smokers�� motivation to smoke (Gilbert, Sharpe, Ramanaiah, Detwiler, & Anderson, 2000; Joffe, Lowe, & Fisher, 1981; Tate & Stanton, 1990).

The mesolimbic DA system has been implicated in the rewarding (Corrigall et al., 1992; Di Chiara & Imperato, 1988; Wise & Rompr��, 1989), psychomotor (Clarke, Fu, Jakubovic, & Fibiger, 1988; Wise & Bozarth, 1987), cognitive (Koob & Le Moal, 2001; Levin & Simon, 1998; Maskos et al., 2005), and affective effects of nicotine (Cinciripini et al., 2004; David et al., 2003; Gilbert, 1995; Gilbert et al., 2004; Koob & Le Moal). The present study examined the association of TaqIA polymorphism with self-reported motivations to smoke and craving in habitual smokers prior and subsequent to quitting smoking.

Based on the known involvement of DA in drug craving (Berridge, 2007; Robinson & Berridge, 1993; Wise, 1988), we predicted that A1 relative to A2/A2 carriers would experience stronger craving both prior to and during smoking abstinence and would report smoking more for pleasure seeking, psychomotor stimulation, cognitive Dacomitinib enhancement, and negative affect reduction. Given recent evidence for interactions between this gene variant and sex on smoking behavior (Munaf��, Johnstone, Murphy, & Aveyard, 2009; Munaf��, Timpson, et al., 2009), sex effects and the interactions on motivation to smoke were also investigated.