View clinical trials related to Substance-Related Disorders.
Filter by:Background: - Cues related to past drug use induce a particular pattern of brain activation, which has been correlated with craving for cocaine in active cocaine abusers. Researchers are interested in determining the role of the brain chemical dopamine in cue-elicited as well as spontaneous craving for cocaine. - To study the role of dopamine in cocaine craving, researchers will use positron emission tomography (PET) to compare the neural reactions of cocaine users with those of non-substance-abusing healthy volunteers. Researchers hope that the data gathered from this study will lead to the development of more effective anti-craving medications. Objectives: - To clarify the role of dopamine in cue-elicited responses that contribute to cocaine abuse. - To determine if PET results of this study differ with various means of administering PET chemicals. Eligibility: - Individuals 21 to 44 years of age who are either current cocaine users (at least twice per week) or healthy volunteers without a history of drug abuse. Design: - Cocaine-using participants will enter the inpatient clinical research ward at the National Institute on Drug Abuse (NIDA) Addiction Research Center for 2 nights before the day of the study. In addition, these participants will stay overnight at NIDA the evening after each PET session and will be discharged the following day. Cocaine-using participants will be required to perform a balance test before the study to provide a baseline response in case they require anti-anxiety medications to cope with the effects of the study. - Control subjects will not be required to stay overnight and will arrive as outpatients for the PET session. All participants will be required to abstain from alcohol and caffeine consumption from midnight before each study session, and will not be permitted to smoke on the day of testing. - - On the day of the study, participants will undergo a practice session to set up the PET scanning equipment. Following the practice session, participants will be shown video recordings of images that are related to nature (e.g., seashells) or to drug abuse (e.g., drug paraphernalia). Participant reactions will be studied through the PET monitoring, and the study will be conducted in two separate PET sessions with a break in between. Individuals in the cocaine-using group may receive anti-anxiety medication if the stimulus cues increase anxiety related to cocaine craving. - Different groups of participants will receive different methods of PET chemical administration, and researchers will compare these methods.
Background: - Environmental cues frequently induce expectancies in individuals that may strongly influence the actual experience associated with the cue. This has both positive and negative consequences for behavior and decision making. For instance, when an addicted individual experiences cues associated with imminent drug taking, an expectancy of the coming experience is also formed and very likely has an effect on the subsequent experience of the drug. - Researchers are interested in studying how the brain responds to these kinds of environmental cues and expectancies in order to learn more about addiction and craving in substance-abusing individuals. Objectives: - To compare the response to rewards (both drug-related and non-drug-related) in cocaine users and non-using individuals. - To study the effect of expectation on reward-related (both drug-induced and non-drug-induced) responses and brain activity in cocaine users and non-using individuals. Eligibility: -Individuals between 18 and 45 years of age who are regular cocaine users but otherwise healthy, or healthy individuals who are not cocaine users. Design: - This study involves two experiments. Participants will be assigned to one or both experiments. - Participants must not use any drugs for at least 3 days before the visit, may not consume alcohol for 24 hours before the visit, and may not consume caffeinated beverages for 12 hours before the visit. On the day of the visit, participants will provide both urine and breath samples to test for drug/alcohol use. - Experiment 1: In the MRI scanner, participants will respond to questions and images on a screen, and will receive small amounts of flavored liquid (chocolate or cherry) through a tube in the mouth. - Experiment 2: In the MRI scanner, participants will respond to questions and images on a screen, and will receive injections of liquid (saline solution or a drug that provides a high similar to cocaine) through an intravenous line. Participants in this experiment will return for follow-up visits and provide urine samples for further study. - The specific assignment (to Experiment 1 or Experiment 2 or both experiments) will determine the number of study days and follow-up visits required.
Background: - The National Institute on Drug Abuse (NIDA) uses a standardized set of procedures to develop a pool of potential participants for research studies. Because some of the data collected during screening are used later for research, the screening itself is considered a study. An applicant to any NIDA study is considered a participant in NIDA screening. Objectives: - To identify, recruit, and screen participants for NIDA research protocols. Eligibility: - Individuals 18 years of age and older who are able to provide informed consent. Design: - Individuals who are eligible for screening will undergo two interviews: a telephone interview and an in-person interview. The phone interview will determine eligibility for the in-person interview. - The in-person interview may require up to five visits to NIDA. The in-person visit will involve any or all of the following procedures: (1) full physical examination and medical history; (2) psychiatric interview; (3) psychological testing; (4) electrocardiogram; (5) samples of blood, urine, and hair; and (6) other minimally invasive procedures as directed by the research staff. - During screening, a photograph will be taken for confirmation of identity during subsequent visits for other studies. - No clinical care will be provided as part of screening.
Background: - Relapse to drug abuse often happens in the presence of stimuli that are associated with previous drug use, also known as cues. Drug-taking behavior appears to be partly controlled by such cues. Some research suggests that cue-induced craving states are responsible for drug use and relapse, but other research suggests that cues can control drug taking without conscious craving or even awareness. Researchers are interested in using functional magnetic resonance imaging (fMRI) to study how individuals respond to drug-related cues and how these cues affect craving on a conscious or unconscious level. Objectives: - To determine how drug-related stimuli (cues) affect thinking, information processing, and body reactions in current drug users. Eligibility: - Individuals between 18 and 50 years of age who are dependent on either tobacco or crack-cocaine, or are healthy volunteers who are not dependent on either drug. Design: - The study will require two sessions, a training session and a testing session, that will take place within 48 hours of each other. Between the two test sessions, participants may not consume alcohol, tobacco, or illegal drugs, and must restrict caffeine consumption. - During the first session, participants will complete questionnaires about tobacco/cocaine use and craving, and will be trained on the tasks to be performed in the MRI scanner. - During the second session, participants will perform concentration tasks and look at pictures, some of which will be tobacco/cocaine related. Body reactions such as heart rate, pupil dilation, and sweating will be measured during this session. Some participants will have actual MRI scanning, while others will have mock MRI scanning. - After the MRI session, participants will complete questionnaires about craving and responses to the scan.
Background: - Cocaine affects the brain's ability to process information. However, different people respond to cocaine in different ways, and differences in brain structure and function may affect how cocaine alters brain activity. By using functional magnetic resonance imaging (fMRI) to monitor brain activity during tasks that provide simple rewards, researchers hope to better understand how the brain responds to rewards and how this response is affected by drugs like cocaine. Objectives: - To determine the effect of cocaine administration on the reward experience in cocaine-dependent individuals. - To study genetic and personality factors that may contribute to cocaine dependence. Eligibility: - Individuals between 18 and 45 years of age who either are cocaine-dependent and not seeking treatment or are healthy volunteers. Design: - Participants will be asked to avoid consuming alcohol and restrict consumption of caffeine prior to the study. Participants provide urine and breath samples to be tested for chemicals that may interfere with the study. - All participants will complete a training session and at least one fMRI scanning session. During the training session, participants will be introduced to the reward tasks and MRI equipment. - Healthy volunteers will have a single fMRI session that will involve reward tasks to be completed during the scanning. Rewards will include small amounts of fruit juice and the opportunity to win money. - Cocaine-dependent participants will have a training session and three experimental sessions including 1) a mock MRI scan to test cocaine tolerance, 2) one fMRI scan with reward tasks after administration of IV cocaine, and 3) one fMRI scan with reward tasks after administration of IV placebo (saline solution). Rewards will include small amounts of fruit juice and the opportunity to win money. - In addition to the scans, participants will provide a blood sample for further study and will answer questionnaires provided by the researchers.
The proposed study will evaluate the safety, tolerability, pharmacokinetics (PK) and pharmacodynamics of repeated oral doses of GSK618334 in healthy male and female volunteers.
Background: - New research on genetics and the human genome has helped to identify certain genes that affect specific parts of the brain, including the parts that may be involved in drug use and dependency. Researchers are interested in studying both genetic information and brain activity to better understand variations in brain function among individuals. Objectives: - To study brain activity in conjunction with specific genetic information provided by healthy volunteers including smokers, non-smokers, people with drug dependence, and those who do not have any dependence on any substance. Eligibility: - Healthy volunteers between 18 and 50 years of age. Design: - This is an 8 10 hour study which may be completed in 1, 2, or 3 visits. - Participants will complete questionnaires about emotional and psychological responses to different situations, including stressful situations. - Participants will have a training session in a mock (fake) scanner to practice tasks to be completed in the real scanner. - Participants will have the following two types of magnetic resonance imaging (MRI) scans in one scan session of the brain: - A structural MRI scan to provide basic information about each participant's brain. - A functional MRI scanning session, in which participants will perform a memory task to provide information about brain activity. - Participants will provide blood samples for research and testing....
Background: - Relapse following cigarette abstinence remains a common problem for smokers who are attempting to quit. Most research has focused on the acute withdrawal phase that occurs within the first 48 hours to 1 week after quitting; however, more information is needed on the experiences of smokers in longer durations of abstinence. Objectives: - To study the effects of long-term smoking abstinence. - To study the effects of cigarette-related cues on craving in longer periods of smoking abstinence. Eligibility: - Individuals at least 18 years of age who are current smokers (at least 10 cigarettes per day) and who want to quit but are not currently attempting to quit. Design: - Participants will be randomly assigned to abstain from all nicotine use for 7, 14, or 35 days. A fourth group of participants will also abstain for 35 days, but will undergo more testing sessions than the other groups. - All participants will have an initial orientation session in which they will complete questionnaires about their smoking habits and will respond to smoking-related cues to provide information about their cravings. - Participants will visit the clinic daily during their abstinence period, and provide urine and breath samples to test for tobacco use. Participants will receive compensation for every day that they do not use tobacco. - On the end day of the abstinence period, participants will return to the clinic, provide urine and breath samples, and undergo testing of their responses to smoking-related cues. Participants in the fourth group will have these tests on Days 7, 14, and 35 of abstinence; other participants will have the tests only once, at the end of their abstinence period. - After the required abstinence period, participants will enter a 5-day step-down period. They will continue to report to the clinic for breath and urine testing, and they will receive payments for abstinence that decrease in value across days. - After the step-down period, for the final 12 days of the study, participants will report to the clinic every 3 days to give urine and breath samples and to report the number of cigarettes smoked.
Background: - Many cigarette smokers claim that smoking helps them stay alert and improves their concentration, and have reported problems in attention 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 pay attention. Knowing which aspects of attention are affected by nicotine may help produce new medications and therapies to help people successfully stop smoking. Objectives: - To investigate the dose-related effects of nicotine on the ability to pay attention in smokers and nonsmokers. - To compare the effects of nicotine in smokers and nonsmokers. Eligibility: - Individuals between 18 and 50 years of age who are either current smokers (at least 15 cigarettes per day on average for at least 2 years) or healthy, nonsmoking volunteers. Design: - The study will consist of one training session and three testing sessions. Each session will last about 2 hours. - The training session will introduce participants to the study tests and evaluate their tolerance of the two levels of nicotine nasal spray used in the study. Smokers will receive the higher dose of nicotine to introduce them to the effects of the spray. Nonsmokers will be given first the lower dose of the spray, followed by higher dose at least 30 minutes later. Nonsmoking participants who cannot tolerate the higher dose will not continue in the study. - At the start of each testing session, smokers will have one cigarette to standardize the time of the most recent exposure to nicotine. - During the testing sessions, participants will receive a placebo spray, a lower dose of nicotine, or a higher dose of nicotine, and then will be asked to perform tests that evaluate mood, attention, and performance.
Drug use (DU) is a major risk factor for HIV infection in many regions of the world. However, as highly active antiretroviral therapy (HAART) has been rolled out in South and South East Asia, less than 2% of individuals initiated on HAART were drug users (DUs) or former DUs, despite the fact that approximately 20% of HIV infections in the region are ascribed to DU. India is home to about 2.4 million HIV-infected individuals. Though, injection drug users contribute to only about 3% of all HIV infections in India; it is estimated that there are between 168,000 and 1.1 million DUs in India with HIV prevalence about 30%. Novel approaches are needed to engage disenfranchised populations in HIV care in lower and middle income countries, where the burden of HIV disease is growing. Incentive-based strategies (or contingency management) have been shown to be effective in reducing illicit drug use, smoking cessation, and weight loss. Short-term pilot studies have also shown that incentive-based strategies can improve electronically-monitored rates of adherence to HAART in the US, and a recent study in Africa showed that a small incentive approximately doubled the rate that individuals returned to learn the results of their HIV test. However, to date there is no experience with the use of incentive-based interventions to improve engagement into care and risk-reduction among out-of-care HIV-infected DUs in developing world settings. The investigators propose to conduct pilot randomized trial comparing a voucher incentive strategy to a control condition to improve engagement in HIV care and HIV treatment outcomes among out-of-care, treatment-eligible, HIV-infected DUs in Chennai, India. Subjects in the incentive arm will be eligible to earn incentive vouchers for 1) initiating HAART at a government-sanctioned HIV treatment clinic, 2) adherence to scheduled follow-up visits at the HIV clinic, and 3) achieving suppression of HIV RNA. Subjects will be enrolled from a mature research venue in Chennai, YR Gaitonde Centre for Substance Abuse-related Research (YRGCSAR), which focuses the epidemiology and natural history of HIV in DUs. Preliminary data from this pilot study will be used to inform the design of a phase-III study.