Jennifer A. Minnix, Ph.D. - US grants

DESCRIPTION (provided by applicant): The focus of this proposal is to provide the applicant with the skills, experience, and mentoring to become an independent researcher with a focus on understanding the neurobehavioral determinants of nicotine dependence. The training plan outlined in this proposal will allow me to expand my skills by providing an opportunity to become proficient in the use of event-related potential (ERP) electroencephalography (EEG) techniques to study attentional and emotional mechanisms related to nicotine dependence. This work will be conducted at the University of Texas M. D. Anderson Cancer Center, where I will be mentored by distinguished scientists in the field of nicotine dependence and emotion. This multidisciplinary team will provide oversight of my research and training experiences by providing specific expertise in the areas of neurobiology, ERP, and emotional processing in smokers. The focus of the Research Plan is to evaluate the effects of nicotine withdrawal on ERP activity associated with a cognitive reappraisal task used to suppress or enhance emotional activation. The specific aims of Study 1 are (a) to examine the relationship between nicotine deprivation and non-deprivation on the extent to which smokers can use cognitive reappraisal strategies to enhance or reduce the emotional intensity of affective stimuli, indexed by the LPP (Late Positive Potential) component of the ERP, and (b) to assess whether ERP measures of cognitive reappraisal correlate with traditional self-reported measures of affect. The specific aims of Study 2 are (a) to evaluate the extent to which pre-quit and post-quit changes in the LPP during a cognitive reappraisal task predicts abstinence, and (b) to assess whether the LPP component of the ERP during cognitive reappraisal correlate with traditional measures of nicotine withdrawal. Both Study 1 and Study 2 are entirely novel in the nicotine dependence and tobacco cessation literature, though the paradigm used in both has been validated using multiple methods. PUBLIC HEALTH RELEVANCE: The results of these studies may contribute to the understanding of key constructs related to negative affect and smoking cessation.

DESCRIPTION (provided by applicant): The adverse health risks of smoking increase significantly with duration and amount smoked per day (i.e., dependence) 2, and it is precisely these heavier and more nicotine dependent smokers that are most refractory to treatment. While current smoking cessation therapies have produced several positive outcomes, no magic bullet has emerged, nor does it seem likely that will be the case. Our research has recently identified a subgroup of smokers with low intrinsic reward sensitivity (IRS-) who are at increased risk of relapse when attempting to quit smoking compared to those with a normal intrinsic reward sensitivity (IRS+). Compared to the IRS+ smokers who exhibited normal responses to intrinsically pleasant stimuli, the IRS- smokers were characterized by blunted brain responses to intrinsically pleasant stimuli and by enhanced responses to cigarette cues. The increased risk for relapse among these IRS- smokers may reflect a sensitivity to the reinforcement enhancing properties of nicotine such that these smokers may rely upon nicotine to experience pleasure from intrinsically rewarding activities. Perhaps a treatment integrating strategies targeted at systematically increasing the motivational value and enjoyment of an individual's environment, such as behavioral activation strategies (BATS), in addition to standard smoking cessation strategies, will result in increased cessation rates in IRS- smokers attempting to quit. In fact, a recent study illustrated that a newly adapted treatment strategy, the objective of this proposal is to evaluate the efficacy of BATS versus standard cessation treatment in IRS- smokers. Reward sensitivity grouping will be determined at baseline using a previously derived algorithm for classifying smokers based on their differential LPP responses to visual cues for natural rewards and smoking. We will randomly assign smokers from each group to receive either standard smoking cessation counseling or BATS (matched for treatment time), in addition to the nicotine patch (NRT). We hypothesize that BATS plus NRT, relative to standard cessation treatment plus NRT, will result in substantially higher abstinence rates in IRS- smokers compared to IRS+ smokers. We predict that the BATS plus NRT effect on abstinence rates in the IRS- smokers will be mediated by self-reported and behavioral measures of several constructs related to the desire for and enjoyment of natural rewards, such as anhedonia, reward valuation, and overall levels of participation in and the enjoyment of rewarding activities. More specifically, we hypothesize that decreased levels of anhedonia, increased levels of reward valuation, and increased levels of environmental reward in IRS- smokers will mediate the effect of BATS plus NRT on abstinence.