Individual Differences in Reward and Impulse Control

Drug Addiction Clinical Trial

Official title: Gene x Environment Interactions as Risk Factors for Addiction

Status Completed

Clinical Trial Summary

Background:

• The risk for becoming addicted to drugs varies among individual, even those using similar drugs in a similar way. It is not known why some people become addicted and others do not. Studies suggest that some genes may increase the risk of addiction. Negative life experiences may also affect the risk of addiction. Researchers want to test smokers and nonsmokers to study genetic and brain function traits that may lead to drug addiction.

Objectives:

• To understand brain function in people who may be at a higher risk of drug addiction.

Eligibility:

• Healthy volunteers between 18 and 55 years of age.

• Smokers (10 to 30 cigarettes per day for more than 2 years) and nonsmokers will be eligible.

Design:

• Participants will be screened with a physical exam and medical history. They will be tested for drug and alcohol use. A blood sample will be collected.

• The study will involve one visit. Participants will have a magnetic resonance imaging (MRI) scan.

• At the visit, participants will answer questions about their health and drug use habits. They will then be trained on the tasks they will do during the MRI scan. After the training, they will have the scan and perform the tasks. The scan and tasks will look at brain function related to rewards and impulsiveness.

• Other computer tests will be given after the scan. These tests will measure learning, memory, and impulsiveness.

Clinical Trial Description

Background: Even under similar drug use patterns, the risk for drug addiction varies from individual to individual. However, the neurobiological mechanisms underlying this variability are poorly understood and characterized. Studies suggest that certain traits observed in substance dependent individuals may actually precede drug use, and could augur future substance dependence. Understanding how the presence of these traits increases vulnerability to substance addiction could aid in the development of early intervention, preventative measures, as well as better treatment strategies.

Objective: The primary goal of this protocol is to improve our understanding of increased susceptibility to developing substance addiction. We focus here on particular gene x environment interactions as increased risk factors for substance dependence. The emphasis is on monoaminergic neurotransmitter-related genes thought to influence adaptability to the environment, and, therefore, on cognitive domains related to dopamine and serotonin: reward and punishment learning, and impulse control. To achieve the above objective, the study will be implemented by using cognitive, genetic and neuroimaging testing in adult addicted individuals along with matched controls.

Subject Population: We focus on adult (18-55 years old) smokers and matched non-smoking controls.

Experimental Design: This study involves cognitive, pharmacological and functional magnetic resonance imaging (fMRI) testing in a between-subject design involving neuroimaging and cognitive testing.

Outcome Measures: The primary outcome measures will be BOLD fMRI activation and behavioral performance on various cognitive tasks that deal with impulse control and reward learning, as a function of gene x environment interactions. ;

Related Conditions & MeSH terms

• Behavior, Addictive
• Drug Addiction
• Substance-Related Disorders
• Vulnerability to Substance Addiction

• NCT number: NCT01621607
• Study type: Observational
• Source: National Institutes of Health Clinical Center (CC)
• Status: Completed
• Start date: June 8, 2012
• Completion date: October 3, 2017