Smoking induced dopamine release: buproprion effects
Creators: name: University Of California Office Of The President
Publisher: name: University of California Office of the President
publisherIdentifier: https://ror.org/00dmfq477
publisherIdentifierScheme: ROR
Year: 2024

description: Despite new medications for the treatment of addiction to cigarettes, abstinence rates after 1 year of treatment remain relatively low (about 1/4 success rate). Bupropion is one of the few medications that has proven to be superior to placebo (inactive pills) in helping smokers maintain abstinence and in reducing craving for cigarettes. We propose to study how bupropion works in human cigarette smokers. The purpose of this study is to determine if a course of treatment with bupropion attenuates the brain concentration of a chemical called dopamine that gets released when smokers smoke a cigarette. A better understanding of the mechanisms of action of current treatments, such as bupropion, may advance the development of more effective treatments for cigarette smoking.
 
 
 
 
 
 Bupropion has many effects on the brain, including increasing the amount of free dopamine. It has been shown in animals and in a small group of humans studied by our group that dopamine gets released in the brain in response to nicotine administration and cigarette smoking. We will use a type of brain imaging called positron emission tomography (or PET) scanning to examine smoking-induced dopamine release before and after treatment with bupropion. While we presume that cigarette smoking does lead to dopamine release in smokers when they smoke a cigarette, the effect of treatment with bupropion on smoking-induced dopamine release has not yet been reported.
 
 
 
 
 
 The central aim of the study is to determine the effect of treatment with bupropion (compared with an inactive pill placebo) on smoking-induced increases in dopamine levels in the brain. We predict that subjects treated with bupropion will have greater attenuation of smoking-induced increases in dopamine than placebo-treated subjects (from before to after treatment). Other goals of the study include the examination of changes in resting dopamine levels from before to after treatment with bupropion and associations between dopamine release and clinical effects of cigarette smoking (such as decreases in craving and nervousness, and increases in euphoria). We will also determine if we can predict who will quit smoking with bupropion based on smoking-induced increases in brain dopamine before.
 
 
 
 
 
 Heavy smokers (who smoke at least 15 cigarettes per day) who are addicted to cigarettes will have PET scanning sessions using a new type of brain imaging that examines dopamine levels in the brain. Subjects will smoke during the PET scans using a special cigarette smoke delivery system (a hookah) that was designed by our group for use in brain imaging studies. Subjects will be randomly assigned to be treated with either bupropion or an inactive pill placebo and will have a PET session before and after a standard course of treatment for 4 weeks to determine changes in brain dopamine concentration in response to smoking. Because some subjects will be assigned to an inactive treatment, all subjects will be offered a free course of active treatment after they complete the study.