Active clinical trials for "Tobacco Use Disorder"

This project will examine the impact of very low nicotine content (VLNC) cigarettes in a complex tobacco and nicotine product marketplace. We will compare the number of cigarettes smoked and cigarette-free days in an experimental marketplace that contains VLNC cigarettes versus normal nicotine content (NNC) cigarettes.

Cerebral oxygenation and blood flow in tobacco use disorder and their relation to smoking abstinence will be measured with MRI" ändern in "Cerebral oxygenation and blood flow in tobacco use disorder

This study plans to investigate whether using electronic cigarettes (e-cigarettes) or skin patches containing nicotine affects switching from smoking conventional combustible (burning) cigarettes.

Background: - Nicotine addiction often makes it difficult to stop smoking. Researchers want to understand the areas of the brain that are important in nicotine addiction. They will use a type of brain stimulation called repetitive transcranial magnetic stimulation (rTMS) to look at part of the brain that may be involved in nicotine addiction. They will see how these areas affect brain function, thinking, and decision making. For this study, rTMS will first be tested on nonsmokers, then smokers will be recruited at a later time. Objectives: - To study areas of the brain involved in nicotine addiction. Eligibility: - Individuals at least 18 years of age who do not smoke. Design: Participants will be screened with a physical exam and medical history. They will also provide a urine sample. There will be four study sessions. The first session will involve a magnetic resonance imaging (MRI) scan. The other three visits will involve rTMS and MRI scans. The first MRI scan will take a baseline picture of the brain. Participants will also practice the tasks for the other three sessions in a mock scanner. At the next three visits, participants will have rTMS and MRI scans. Two visits will involve rTMS; the other visit will involve mock rTMS with no actual magnetic stimulation. During the MRI scans, participants will perform tasks that involve decision making.

The investigators propose to use positron emission tomography (PET) imaging to determine whether nicotinic receptor availability at pretreatment predicts smoking cessation success. The investigators will recruit 30 smokers from those enrolled in the Pharmacogenetics of Nicotine Addiction Treatment clinical trial. The investigators will measure nicotinic receptor availability using the PET radioligand 2-[18F]FA, after overnight abstinence and prior to initiation of treatment.

Background: - Researchers have been studying behavioral components of nicotine addiction by looking at how drugs have a reinforcing effect, connecting the stimulation provided by the drug (nicotine) to the behavior that produces it (smoking). Based on previous studies, researchers are interested in learning more about how nicotine affects current smokers' responses to psychological tests and smoking-related cues, and in studying whether certain kinds of genetic background may affect smokers' responses to these kinds of studies. Objectives: To compare the effect of nicotine versus denicotinized cigarettes during specific psychological tests. To compare the effects of smoking cues versus neutral cues on craving, mood, and autonomic response. To study the effect of genes on nicotine reinforcement and smoking-cue reactivity. Eligibility: - Individuals between 18 and 64 years of age who are current smokers (at least 10 cigarettes per day for at least 1 year) and are not currently interested in reducing their smoking or seeking treatment for tobacco dependence. Design: Pilot session: Participants will practice smoking using the measuring equipment that will be used in the study. After successful practice, participants will read or listen to music for 1 hour, during which they are not allowed to smoke. After the 1-hour period, participants will sample study cigarettes that have different levels of nicotine, and will be asked to guess whether the cigarettes are normal study cigarettes or denicotinized cigarettes. Baseline session: Blood, urine, and breath samples will be taken at the start of the session. Participants will smoke part of an initial cigarette, and then will read or listen to music for 1 hour, during which they are not allowed to smoke. After the 1-hour period, participants will give another breath sample and will complete questionnaires about mood and concentration levels. Trial sessions: Participants will smoke study cigarettes, and will be asked to either respond to questions about perceived nicotine levels in the cigarettes or press a lever for the chance to be rewarded with additional puffs of the cigarette. After the session, participants will give another breath sample and will complete questionnaires about mood and concentration levels. Participants will also participate in cue-reactivity sessions to test the body's physiological response to smoking cues (a pack of cigarettes) and neutral cues (a pack of unsharpened pencils). After the session, participants will complete questionnaires on mood and concentration 15, 30, 45, and 60 minutes after the session. At the conclusion of the last experimental session, participants will discuss the study with researchers, and may receive a referral list of smoking treatment programs.

Background: - A brain circuit called the default network is the brain circuit that is active when the brain is at rest; that is, when individuals are not concentrating on specific tasks. Previous research has shown that the default network functions differently in people with schizophrenia and Alzheimer s disease, and may contribute to the problems with memory and concentration that can affect people who have these conditions. Studies have also shown that nicotine affects the default network, but more research is needed on the ways in which nicotinic receptors may change activity in these regions and thereby affect individuals ability to concentrate on specific tasks. Objectives: - To determine whether and how nicotine and mecamylamine, a drug that blocks nicotinic receptors, affect the default network in nonsmokers in ways that improve thinking and concentration. Eligibility: Healthy, right-handed volunteers between 21 and 50 years of age. Volunteers must not have used any kind of tobacco product in the past 2 years. Design: This study involves an initial screening visit, a training visit, and three testing visits. Participants will be screened with a medical history and physical examination, as well as blood and urine samples and questions about smoking history. Participants will have an initial training session to practice the tasks that will be done during magnetic resonance imaging scans at the testing visits. These tasks will test participants concentration and memory. Participants will have three test sessions with the following combinations of study drugs: (1) a nicotine patch and a placebo capsule, (2) a placebo patch and a capsule of mecamylamine, or (3) a placebo patch and capsule. Different combinations will be given at each visit, and participants will not know which one they receive. Participants will perform the same concentration and memory tasks at each testing visit, and will provide a blood sample after each visit to determine levels of nicotine and mecamylamine.

This study will evaluate effects of smoking on the dopaminergic system by using PET tomography with new radioligand, [11C]-(+)-PHNO. Our primary hypothesis is that smoking a cigarette will produce dopamine release and this release can be measured using PET imaging and the [11C]-(+)-PHNO radiotracer. The secondary hypothesis is that this smoking induced dopamine release will be correlated with subjective craving and anxiety ratings.

The primary purpose of this investigation is to determine the predictive value of task persistence as measured by a mirror tracing task. A secondary purpose is to evaluate differences in task persistence in smokers with or without schizophrenia. It is hypothesized that task persistence in smokers in both diagnostic categories (schizophrenia and no schizophrenia) will predict tobacco dependence treatment outcome at one and six months. It is also hypothesized that smokers with schizophrenia will show lower levels of task persistence after controlling for other motor skills than smokers without schizophrenia.

Background: - Many cigarette smokers claim that smoking improves their ability to think and concentrate, and have reported problems in thinking and concentration after quitting smoking. Some research has indicated that nicotine can enhance certain aspects of attention and memory in humans. However, more research is needed to determine how nicotine affects different elements of the brain s ability to think, pay attention, respond to rewards, and make decisions. Researchers are interested in using functional magnetic resonance imaging (fMRI) to study the effects of nicotine on brain function and activity. Objectives: - To determine the effects of nicotine on attentional and other thinking processes, including reward-seeking behavior. Eligibility: - Individuals between 18 and 50 years of age who are either current smokers (10 or more cigarettes per day for at least 1 year) or nonsmokers. Design: The study has four experiments. Each experiment requires two MRI scanning sessions and a training session. Participant can do one or all of the experiments. Participants will receive training on the types of computerized tests that will be given during the active portion of the study. Participants will also fill out questionnaires on nicotine use and other alcohol and drug use, and provide breath and urine samples. During the test sessions, participants will have fMRI scanning while performing up to four different sets of tasks that test attention, memory, concentration, reward-seeking behavior, and decision making. Smokers will wear a nicotine patch or placebo patch during the test sessions, but will not be told which patch they are receiving. The order of these sessions will be different for individual participants. Participants will provide blood and urine samples throughout the research study for evaluation purposes.