8 Clinical Trials for Various Conditions
The current abuse liability study aims to assess the potential for co-administration of naltrexone (NTX) to reduce the abuse potential of methylphenidate (MPH).
The purpose of this study is to estimate the observed incidence of the health outcomes (suicide attempt or ideation, suicide ideation, suicide attempt, psychosis, and substance abuse) in a cohort of participants diagnosed with attention deficit hyperactivity disorder (ADHD) who are first-line new therapy with methylphenidate monotherapy, lisdexamfetamine monotherapy, atomoxetine monotherapy, amphetamine/dextroamphetamine combo therapy, and either methylphenidate/lisdexamfetamine/atomoxetine monotherapy or amphetamine/dextroamphetamine combo therapy during the 'on treatment' period from 7 days after the start of exposure through the end of exposure (treatment discontinuation for at least 60 days) and the 'intent to treat' period from 7 days after start of treatment to end of continuous observation; and to compare the hazards of outcomes (suicide attempt or ideation, suicide ideation, suicide attempt, psychosis, and substance abuse) in the target cohort (participants diagnosed with ADHD who are first-line monotherapy new users of methylphenidate) versus each comparator cohort (patients diagnosed with ADHD who are first-line newly exposed to lisdexamfetamine monotherapy, atomoxetine monotherapy, amphetamine/dextroamphetamine combo therapy) during the 'on treatment' period from 7 days after the start of exposure through the end of exposure (treatment discontinuation for at least 60 days) and the 'intent to treat' period from 7 days after start of treatment to end of continuous observation.
Background: * Research has shown that several human genes have been associated with vulnerability to substance abuse and dependence. However, little is known about how people with these genetic tendencies react to drugs in controlled settings. * Methylphenidate, also known as Ritalin, is commonly prescribed for a number of conditions, including attention deficit disorder. Because methylphenidate is widely used in studies of brain chemistry and behavior and has relatively low risks associated with it use, researchers are interested in seeing how it affects the thinking processes of people with apparent genetic vulnerability to drug abuse. Objectives: - To evaluate whether individuals with apparent genetic vulnerability to drug abuse react differently to methylphenidate than people who do not have this vulnerability. Eligibility: - Individuals at least 18 years of age or older who have participated in the NIDA protocol Allelic Linkage in Substance Abuse. Design: * Participants will be asked to avoid using a number of over-the-counter medications, including antihistamines, cough medicines, and nasal decongestants, for 24 hours before the study day. Participants will also be asked to avoid consuming caffeinated beverages, nicotine or tobacco products, or alcohol on the morning of the day of the study, and will provide a urine sample at the start of the study to be tested for chemicals that may interfere with the study. * Because of the nature of the study drug, participants will not be allowed to drive to the clinical center on the day of the study. (Return transportation will be arranged.) * At the start of the study, participants will take two tablets (each 1 hour apart), and will not be told whether the tablets are the study drug or a placebo. * Participants will give regular answers to questions about mood and thinking processes on a computer for approximately 5 hours. Blood samples will be taken during this part of the study.
Many cocaine dependent individuals are also diagnosed with Attention Deficit Hyperactivity Disorder (ADHD). Methylphenidate (Ritalin) is currently approved to treat individuals diagnosed with ADHD. The purpose of this study is to determine the effectiveness of methylphenidate in treating ADHD symptoms in cocaine dependent individuals.
This is a human inpatient clinical pharmacology study to assess potential interactions between intravenous (i.v.) methamphetamine infusion and oral osmotic release methylphenidate (OROS-MPH). The primary objective of this study is to determine the safety of the OROS-MPH concurrent with i.v. d-methamphetamine infusions of 15 mg and 30 mg. Safety outcome measures include cardiovascular responses \[heart rate (HR), blood pressure (BP), and electrocardiograph (ECG) measurements\], oral temperature, adverse events (AEs), and clinical laboratory analyses.
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: * Brain imaging studies, genetic research, and investigations of stress have provided more information about the role of dopamine in processing reward and punishment, and in vulnerability to substance dependence. Researchers are interested in learning more about how the brain responds to rewards, including drugs of abuse, and how these responses may involve genetic factors or previous stressful events. * Researchers intend to use the drug amphetamine to increase levels of dopamine in the brain and study the effects through two kinds of scanning: functional magnetic resonance imaging (fMRI) and positron emission tomography (PET). Objectives: * To examine the relationship among dopamine function, brain activity, reward processing, genetic profile and exposure to stress in normal healthy adults. * To examine the variation in these factors between normal healthy adults and individuals with current cocaine-dependence. Eligibility: - Individuals 18 to 45 years of age who are either current cocaine users or healthy volunteers with no history of substance abuse or dependence. Design: * The study will consist of an initial evaluation session and six study visits, four of which will involve fMRI scans (3 hours each) and two of which will involve PET scans (8 to 9 hours each). * Cocaine-using participants will enter the inpatient clinical research ward at the National Institute on Drug Abuse Addiction Research Center the night before each scanning session and will be discharged the following day. Healthy volunteer subjects will not be required to stay overnight and will arrive as outpatients for the PET session. Participants will not be released until researchers have determined that participants are not experiencing significant effects of the drug. * Initial session (1): Participants will complete questionnaires about past reactions to stressful situations, and will be trained to do thinking tasks that will be performed in fMRI visits. The tasks will be practiced in a mockup of an MRI machine. * MRI sessions (2-5): Participants will receive either oral amphetamine or a placebo, and will perform thinking, short-term memory, and reward tasks during MRI scanning as directed by researchers. * PET sessions (6-8): Participants will receive either oral amphetamine or a placebo, and will provide blood samples during the PET scanning sessions. Participants will have short breaks during the PET scanning sessions.
The study team will examine the effects of FDA approved stimulant and non-stimulant medications for ADHD, among youth with ADHD and with and without Oppositional Defiant Disorder (ODD) or Conduct Disorder (CD), on reward systems of the brain using fMRI.