John Hughes’ Research Grant Abstracts
Natural History of Attempts to Stop Smoking, National Institute on Drug Abuse
Smoking cessation can be enhanced either by increasing the success of quit attempts or by increasing in the number of quit attempts. Although many studies have determined the variables that influence remaining abstinent after a quit attempt, few have examined the variables that influence the onset of a quit attempt. The current application tests two facets of a model of the processes that lead to a quit attempt. First, we test whether certain environmental cues (e.g., a request from a child to quit smoking or exposure to a smoking-related health message) increase the probability of a quit attempt in the near future. We also examine whether such cues predict attempts over and above the predictive ability of cognitive factors such as self-efficacy and perceived social norms and whether these cognitive factors interact to make cues more powerful predictors. Second, we test whether planning behaviors (e.g. seeking information about treatment) and setting a quit date are common and increase the probability of a quit attempt. We also provide a more rigorous replication test of prior findings that spontaneous, unplanned quit attempts are more successful than delayed, planned quit attempts. In a pilot study, we will develop measures of external cues and planning activities. The main study is a non-treatment, prospective, natural history study. In this study, we will recruit 200 adult daily smokers who are interested in quitting in the next 6 months. They will call an Interactive Voice Recording (IVR) system daily and complete mailed or internet questionnaires weekly for 6 months. Our prior work has shown that we can obtain such daily and weekly reports for 6 months with little missing data. The daily IVR will record tobacco use/abstinence, intentions to quit, external cues and planning behaviors. The weekly questionnaires will measure cognitive variables and other outcomes (e.g. other drug use). Data analysis will use multilevel models designed to accommodate many repeated measures over time within participants. The results of this study will a) help develop a model of the causes of smoking cessation attempts, b) guide development of media and individual interventions to motivate smokers to make a quit attempt, and c) provide a more rigorous test of whether spontaneous, impulsive quit attempts should be encouraged rather than delayed, planned quit attempts.
Attempts to Stop/Reduce Marijuana Among Dependent Users, National Institute on Drug Abuse
The major aim of this study is to provide a detailed understanding of attempts to stop or reduce marijuana use that can be used to develop better behavioral treatments for marijuana dependence. The application will provide a prospective description of attempts by dependent adult marijuana users to stop or reduce their marijuana use in a real-world setting. Although prospective, natural history studies describing attempts to stop or reduce alcohol, heroin and tobacco use have proved useful, we know of no such study among adult marijuana users. A pilot study will develop measures and assess compliance with our procedures. The main study will recruit 200 daily, adult marijuana smokers who plan to quit or reduce in the near future. Participants will call an Interactive Voice Recording (IVR) system daily for 3 months to report marijuana use, intentions to change marijuana use, quit/reduction attempts, and events that might increase or decrease the probability of initiating a quit/reduction attempt or the success of an attempt. Participants will be called weekly to obtain more detailed measures such as other drug use, self-efficacy, psychiatric/medical symptoms, and treatment seeking. Phone follow-ups at 4, 5 and 6 months will track marijuana and other drug use and dependence/abuse.
Does smoking cessation cause anhedonia? A test of pre-clinical findings, National Institute on Drug Abuse
Recent animal research indicates acute nicotine increases the reinforcing effects of other rewards; however, chronic use of nicotine recruits an opponent process that counteracts the acute effects of nicotine and decreases sensitivity to rewards. When nicotine is discontinued in animals, this opponent process persists and the resultant decreased sensitivity to rewards may be a cause of nicotine withdrawal symptoms such as depression and a cause of relapse back to smoking. Although this animal model is widely cited, whether decreased reward sensitivity occurs when smokers stop smoking is unclear. We propose an experimental test that focuses on whether abstinent smokers a) are less sensitive to monetary rewards during an operant task and/or b) report anhedonia (less pleasure from rewards) and apathy (less motivation to seek rewards). We will recruit 120 current smokers who plan to quit smoking for good to smoke their usual amount for one week and then will abstain for 4 weeks. To insure an adequate number of continuously abstinent smokers and to decrease selection bias, we will use monetary contingencies to encourage abstinence. We anticipate this will produce > 70 smokers who remain abstinent for all 4 weeks. To assist in interpretation of results, we will also recruit a comparison group of 70 long-abstinent former smokers to be measured on the same schedule. We will measure reward sensitivity three times each week using a) progressive ratio (PR) responding for monetary rewards and b) self-report measures of anhedonia and apathy scales. If reward sensitivity changes with abstinence, secondary aims will be to determine a) its magnitude, incidence and time course; b) whether it exhibits the time course expected of a withdrawal effect, c) whether reward sensitivity becomes similar to the level among long-abstinent smokers and c) whether decreased reward sensitivity could be the basis for much of withdrawal discomfort. The results of this study will be an important translational test of the leading animal model of nicotine withdrawal. If we find decreased reward sensitivity, this would suggest revisions in clinical descriptions of nicotine withdrawal, new targets for behavioral and pharmacological interventions and new treatments for smoking cessation (e.g., increased exposure to rewarding events). If reward sensitivity does not change with abstinence, then (given the adequacy of our test) this would suggest a widely-cited animal model of abstinence effects may not be generalizable to human attempts to stop smoking.
Treatment for Smoking Lapses and Relapses, National Cancer Institute
Over-the-counter nicotine replacement therapy (OTC NRT) is, by far, the most common treatment for smoking cessation in the US. Over 80% of those using NRT will lapse and return to smoking. One possible reason for this high rate of treatment failure is that smokers are instructed to stop medication when they lapse (in contrast to recommendations to increase medication dose when heroin users lapse). Recent indirect evidence suggests that, in fact, a lapse is the most important time to continue NRT. We propose a randomized controlled trial of continued NRT post-lapse vs. stopping NRT post-lapse. Smokers who want to quit will receive, counseling, stop abruptly and begin NRT. All psychosocial treatment will occur via phone and medications via mail. Instructions and rationales for continuing or stopping NRT during a lapse episode will be delivered via written material, Interactive Voice Response (IVR) phone messages and reinforced during phone counseling. We will enter 1000 smokers and anticipate observing 580 lapse while using NRT. We hypothesize our intervention to continue NRT use upon a lapse will increase 6 month point prevalent abstinence with an OR of 2.0. We will also examine compliance with instructions and possible behavioral mechanisms of efficacy (e.g. does continued NRT reduce nicotine reward from cigarettes) as well as the incidence of serious adverse events when participants are concurrently smoking and using NRT after a lapse. This study will be the first direct experimental test of whether continuing NRT after a relapse increases abstinence and is safe. Positive results would suggest the package instructions for NRT, treatment guidelines and training programs should change to explicitly encourage smokers to continue NRT treatment after a lapse.
Last modified October 26 2011 09:30 AM