“…Baker, Piper, McCarthy, Majeskie, and Fiore's (2004) reformulation of the negative reinforcement model of drug addiction proposes that negative affect is the single most important motivational factor driving addictive substance use, and negative affect is conceptualized as a hallmark of withdrawal. Furthermore, empirical data indicate that negative affect ( Brandon, 1994 ;Kenford et al, 2002 ;Piasecki et al, 2000 ;Shiffman, Paty, Gnys, Kassel, & Hickcox, 1996 ) and affective vulnerability ( Borrelli, Bock, King, Pinto, & Marcus, 1996 ;Glassman et al, 1990 ;Niaura et al, 1999 ;Wetter et al, 1999 ) enhance the risk of relapse. Wetter and colleagues (1994) found that strong expectancies for the negative affect reduction properties of smoking predicted both withdrawal severity and relapse.…”