One approach to reducing drug use and abuse is to identify factors that differentiate current users from nonusers (never-users and ex-users) and then to determine whether the factors in question are causally associated with the drug use. If they are causally related, this information may be used to identify at-risk populations, to develop targeted treatments or interventions and to understand how drug exposure impacts brain function. Impulsivity may be one of those factors. A growing body of literature indicates that drug users are more impulsive than nonusers, where impulsivity has been defined variously as a reduced ability to delay gratification or to inhibit behavior, heightened risk- and sensation-seeking, acting without weighing the consequences appropriately, etc. However, the direction of causality between impulsivity and drug use is unclear, and the mechanisms underlying this relationship are unknown. High levels of impulsivity might cause people to experiment with cigarettes, and then continue to use. Alternatively, the actions of nicotine might acutely or chronically increase impulsive decision-making. Indeed it is possible that both processes may be involved - heightened impulsivity precipitating smoking initiation, then doses of nicotine increasing impulsive decision-making, which in turn decreases the likelihood of successful quitting. The current proposal outlines 5 experiments that will address the relationship between impulsivity and several different aspects of drug use using cigarette smoking (nicotine) as the model of drug use under investigation. The first 3 studies examine the relationship between baseline measures of impulsivity and smoking cessation treatment outcomes (Study 1), the subjective aversiveness of short-term withdrawal and relief from withdrawal (Study 2), and the intensity of cigarette smoking (Study 3). These studies will result in a better understanding of how general behavioral traits (a.k.a. personality) can impact how drugs are used and how those traits influence their continued use. The final 2 studies examine how state measures of impulsivity, assessed using laboratory tasks to assess impulsive decision-making, are affected by abstinence from nicotine (Study 4) and increases in systemic nicotine in smokers and nonsmokers (Study 5). It is hoped that these studies will result in a better understanding of the factors impacting drug use and how drug use can impact decision-making.

Agency
National Institute of Health (NIH)
Institute
National Institute on Drug Abuse (NIDA)
Type
Research Project (R01)
Project #
5R01DA015543-04
Application #
7071158
Study Section
Biobehavioral and Behavioral Processes 3 (BBBP)
Program Officer
Wetherington, Cora Lee
Project Start
2003-09-20
Project End
2008-05-31
Budget Start
2006-06-01
Budget End
2007-05-31
Support Year
4
Fiscal Year
2006
Total Cost
$210,968
Indirect Cost
Name
Oregon Health and Science University
Department
Other Basic Sciences
Type
Schools of Medicine
DUNS #
096997515
City
Portland
State
OR
Country
United States
Zip Code
97239
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Mitchell, Suzanne H; Wilson, Vanessa B (2012) Differences in delay discounting between smokers and nonsmokers remain when both rewards are delayed. Psychopharmacology (Berl) 219:549-62
Mitchell, Suzanne H; Wilson, Vanessa B (2010) The subjective value of delayed and probabilistic outcomes: Outcome size matters for gains but not for losses. Behav Processes 83:36-40
Schwartz, Daniel L; Mitchell, Alex D; Lahna, David L et al. (2010) Global and local morphometric differences in recently abstinent methamphetamine-dependent individuals. Neuroimage 50:1392-401
Hoffman, William F; Schwartz, Daniel L; Huckans, Marilyn S et al. (2008) Cortical activation during delay discounting in abstinent methamphetamine dependent individuals. Psychopharmacology (Berl) 201:183-93
Mitchell, Suzanne H; Schoel, Christiane; Stevens, Alexander A (2008) Mechanisms underlying heightened risk taking in adolescents as compared with adults. Psychon Bull Rev 15:272-7
Hoffman, William F; Moore, Meredith; Templin, Raymond et al. (2006) Neuropsychological function and delay discounting in methamphetamine-dependent individuals. Psychopharmacology (Berl) 188:162-70
Mitchell, Suzanne H (2004) Measuring impulsivity and modeling its association with cigarette smoking. Behav Cogn Neurosci Rev 3:261-75