View clinical trials related to Nicotine Dependence.
Filter by:Background: - One kind of drug craving, known as cue-elicited craving, occurs when a drug user who sees a drug-related cue (such as an image of someone using the drug) begins to feel a craving for the drug. Researchers are interested in studying how cue-elicited craving affects brain activity using functional magnetic resonance imaging (fMRI) and electroencephalography (EEG) data. Objectives: - To determine which parts of the brain are associated with or involved in controlling cue-related craving in smokers. Eligibility: - Individuals between 18 and 50 years of age who are current smokers (10 or more cigarettes per day) and agree to try to abstain from smoking for 1 week during the experiment. Design: - Participants will visit a clinical center for up to four scanning sessions, and will be asked to perform two or three outpatient tasks at home over the course of the study. - Scan 1: Training session with a mock fMRI scanner, followed by an actual fMRI scanning session and EEG in which participants respond to pictures. - Outpatient Task 1: Tolerance test with nicotine patch (worn for 8 hours, followed by 12 additional hours without cigarette use). - Scans 2 and 3: Training session and fMRI scan and testing with either nicotine patch or placebo. Tasks in fMRI involve looking at cues, reporting craving and suppressing craving. - Outpatient Task 2: Participants will keep an electronic diary for 10 to 14 days, responding to questions as directed by the researchers. - Scans 4 and 5: Training session, fMRI scan and EEG, and testing in which participants will be instructed on methods to attempt to control cravings. - Outpatient Task 3: Participants will keep an electronic diary for 14 days. For the first 7 days, participants will be asked to attempt to abstain from nicotine; participants may smoke normally on the second 7 days. - Participants will be contacted 1, 3, 6, and 12 months after the end of the study for follow-up questions on current smoking habits.
The purpose of this study is to better characterize differences in mood, attention, brain activation patterns underlying the beneficial effects of pharmacological treatments previously demonstrated to be help individuals successfully quit tobacco smoking. Smokers will be randomly assigned to one of three treatments: 1) bupropion sustained release (SR), 2) nicotine patch, or 3) placebo patches plus pills across a 45-day period with a 3-week intensive post-treatment follow-up. In addition, 20 percent of the subjects will be randomized to a delayed-quit control group.
The primary aim of this project is to test the effect of exercise on acute nicotine withdrawal. Acute nicotine withdrawal is characterized by a complex array of symptoms associated with increased risk of relapse among individuals attempting smoking cessation. The available remedies do not target all aspects of withdrawal. For example, pharmacologic treatments reduce withdrawal-based craving, but have no effect on cue-related craving, altered sleep, and mood disturbances during withdrawal. Therefore, non-pharmacologic behavioral techniques with the potential to attenuate persistent withdrawal symptoms are needed. We hypothesized that exercise can be a valid non-pharmacologic strategy to improve these domains.
The transdermal nicotine patch is the most widely used form of tobacco dependence treatment in the US and Europe, but most smokers are unable to successfully quit with this form of treatment. Failure to respond to this treatment may, to a large extent, be due to the use of nicotine patches for only 8 weeks, the recommended treatment duration. We have found in a controlled randomized clinical trial that using the nicotine patch for 24 weeks can increase quit rates significantly. We propose here a clinical trial to replicate and extend these results to a community setting in the real-world, using the same research design utilized in clinical trials to demonstrate the effectiveness of methadone maintenance therapy for opiate dependence. Specifically, 540 smokers will receive counseling and standard (8-weeks), extended (24-weeks), or maintenance (52 weeks) therapy with transdermal nicotine patches. The main outcome is biochemically-verified smoking cessation at week 52. The cost-effectiveness, safety, and mechanism of effect (e.g., promotion of recovery following a lapse) for maintenance therapy with transdermal nicotine will also be assessed. The study results may change how we treat nicotine dependence with transdermal nicotine.
Background: - Individuals who have schizophrenia are significantly more likely to smoke than the general population, which leads to increased smoking-related illnesses and high rates of nicotine dependence. Research suggests that high rates of smoking and nicotine addiction in people with schizophrenia are related to the fact that nicotine temporally improves performance in several cognitive tasks, including sensory gating, long-term memory, and visual tracking-all of which are affected by schizophrenia. - Smoking among schizophrenia patients may be a form of self-medication, since nicotine may temporarily treat and improve cognitive deficits caused by schizophrenia. Researchers are interested in studying the effects of nicotine on the brain activity of individuals with schizophrenia to better understand how nicotine affects the brain regions connected to memory, visual tracking, and attention. Objectives: - To identify specific brain regions involved in the anticipatory learning deficits found in schizophrenia patients who smoke. - To determine whether and how nicotine enhances performance in these regions. Eligibility: - Smokers (at least 10 cigarettes per day) between 18 and 50 years of age who either are healthy volunteers or have been diagnosed with schizophrenia/schizoaffective disorder. Design: - Participants will be asked to avoid consuming alcohol and restrict consuming caffeinated beverages for 24 hours before the study days. Participants will provide urine and breath samples at the start of the study to be tested for chemicals that may interfere with the study. - The study will require two to four visits, with two fMRI sessions and other visits for a clinical interview or training. Participants will have a training session with a possible mock MRI scan to learn how to do tasks that track eye movement and measure ability to pay attention. - During the fMRI scanning sessions, participants will receive either a nicotine patch or a placebo patch without nicotine. After the patch is in place, participants will perform tasks while receiving MRI scans. The scans will take up to 2 hours. - Participants will provide blood samples after finishing the MRI sessions.
Background: - Central nicotinic acetylcholine receptors (nAChRs) are the primary target for the action of nicotine. In addition to being involved in tobacco dependence, they are also involved in a variety of brain disorders, including Alzheimer's and Parkinson's diseases. Researchers are interested in developing better ways to study the action of nAChRs to improve treatments for smoking cessation and other problems affected by these receptors. These new study methods may involve different radiotracers, which are drugs that can help show brain activity during positron emission tomography (PET) scanning. Objectives: - To evaluate the feasibility of using a radiotracer, 2-[18F]F-A-85380, in PET scanning of the brain. Eligibility: - Healthy volunteers between 21 and 45 years of age who do not use tobacco. Design: - Participants will be asked to avoid consuming alcohol or using a number of over-the-counter medications, including antihistamines, cough medicines, and nasal decongestants, for 5 days before the study day. Participants provide urine and breath samples at the start of the study to be tested for chemicals that may interfere with the study. - Participants will visit the clinical center the morning of the day before the scanning session to provide blood and urine samples as required. Participants will return and be admitted for an overnight stay later that afternoon or evening. - On the day of the study, participants will receive a single dose of the radiotracer 2-[18F]F-A-85380, and will have a series of PET scans over the next 7 hours and provide blood samples during that time. Participants will spend that night at the clinical center and leave on the morning after the end of the study. - Participants will return for follow-up visits 2 weeks and 1 month after the end of the study.
A substantial body of evidence implicates the endogenous opioid system, and the mu opioid receptor (MOR) in particular, in the reinforcing effects of drugs of abuse, including nicotine. A single nucleotide polymorphism (SNP) in the mu opioid receptor gene (OPRM1 Asp40) is associated with the ability to quit smoking, as well as nicotine reward and withdrawal symptoms. However, the precise mechanism through which this SNP influences nicotine dependence remains unresolved. This positron emission tomography (PET) study will examine whether this OPRM1 SNP alters MOR binding in response to nicotine in human smokers. Specifically, we will use [11 C]carfentanil PET imaging to assess the effects of intravenous (IV) nicotine versus saline (within-subject) on MOR binding potential in 24 chronic smokers genotyped prospectively and stratified by OPRM1 genotype.
Background: - Nicotine addiction is common among people who smoke tobacco, and the addictive properties of nicotine make smoking cessation difficult even for people who want to quit. Research has shown that smoking causes changes in the brain that lead to addiction and craving, but more research is needed to determine how different doses of nicotine and different intervals of receiving nicotine affect brain function. A greater understanding of nicotine's effect on the brain, as studied through functional magnetic resonance imaging (fMRI), may improve the effectiveness of smoking cessation therapies and treatments. Objectives: - To determine the effects of nicotine on brain function and chemistry in experienced cigarette smokers. Eligibility: - Current smokers (at least 20 cigarettes per day for at least 1 year) between 18 and 50 years of age. Design: - The study involves five separate research experiments. Most participants will be involved in only one experiment. - The experiments will evaluate brain activity and function using fMRI. Participants will be trained in a series of tests on cognitive function before beginning the experimental part of the study. - Experiment 1: Participants will have three fMRI scan sessions after receiving different dose levels of intravenous nicotine. - Experiment 2: Participants will have four fMRI scan sessions after receiving two doses of nicotine separated by 1/4, 1/2, 3, and 24 hours. - Experiment 3: Participants will have two sets of nicotine injections separated by 45 minutes, with each injection series containing five rapid injections of small amounts of nicotine (to mimic five puffs on a cigarette). - Experiment 4: Participants will have three fMRI sessions after receiving a single injection of nicotine at three different rates (over 15, 60, or 120 seconds). In addition there will be three more sessions involving a nicotine patch and a nicotine injection as well as a placebo session. - Experiment 5: Participants will have three fMRI sessions that will involve looking at different kinds of pictures related to or not related to smoking after receiving a single injection of nicotine. - Participants will also provide blood samples for further study....
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.
Background: - Drugs of abuse have effects on mood, behavior, thinking, and decision making that may encourage people to continue using them and make it difficult for them to stop. Researchers who study these effects are interested in developing new tests to evaluate how drugs and drug use affect different areas of the brain. - Magnetic resonance imaging (MRI) scans allow researchers to study brain activity and changes to brain function. When specific psychological tests are performed during functional MRI (fMRI) scans, researchers can examine the effects of drug use on the brain. By developing and testing new procedures for fMRI studies, more information can be obtained on brain function and activity in drug-using and non-drug-using individuals, and this information can help develop new treatments and therapies for substance abuse. Objectives: - To evaluate the effects of newly developed psychological procedures to be performed during fMRI scans. Eligibility: - Healthy volunteers between 13 and 65 years of age who are willing to undergo MRI scanning. - Both drug-using and non-drug-using individuals will be selected for this study. Design: - Before the start of the study, participants will complete questionnaires about medical and psychological history, and provide information about past or current drug use. Researchers will introduce the tasks to be performed during the scanning session(s), and will allow participants to practice the test either on a separate computer or on the computer used during the MRI scan. - During the study, participants will be asked to do one or more tasks selected by the researchers. The tasks will be performed on a computer in an MRI machine, and may involve receiving rewards (such as money or sips of juice) for actions, memory and reaction-time tests, or other tests that involve responding to instructions on the screen. - Participants will receive compensation for their participation in the study, including hourly compensation for individual visits and lump-sum compensation for each MRI scan....