Conditions: Healthy
Keywords: Reward Circuitry Impulsivity Family History of Alcoholism NMDA/DA Interactions
Allocation: RANDOMIZED | Intervention model: CROSSOVER
Enrollment: 71
Healthy volunteers: yes

Brief summary:
This project compares Family History Positive (FHP) for alcoholism subjects to matched Family History Negative (FHN) subjects derived from the project Principal Investigator's National Institute on Alcohol Abuse and Alcoholism-funded longitudinal study of drinking behavior in a 2000 college freshman population (known as the Brain and Alcohol Research in College Students study (BARCS)). The age of these subjects is a valuable one at which to capture the transition from harmful use to abuse/dependence. This project explores the effects of memantine in a double-blind, randomized, counterbalanced manner on alcoholism risk-relevant tasks. More specifically, this project studies functional MRI tasks related to different aspects of reward and/or impulsivity-related behavior in different contexts, compares the underlying neural circuitry across tasks, and uses a pharmacologic probe of the glutamatergic system to examine NMDA/DA interactions. The combined measures provide the opportunity to advance our understanding of specific aspects of brain function related to familial alcoholism vulnerability in an already well-characterized population as some members evolve into alcohol abuse. In addition to conventional within-task analyses, functional network connectivity and allied approaches will be used to examine brain networks across tasks.

The investigators will study adult male and female subjects in equal numbers who are either offspring of an alcoholic parent or are FHN matched controls. The investigators will recruit and assess a total of 84 (42 FHP and 42 matched FHN) subjects between the ages of 18-21 years on initial BARCS contact. The investigators will use 4 cognitive tasks during the functional MRI (fMRI) which include: 1) a Monetary Incentive Delay Task that distinguishes networks engaged in motivational (anticipation) and consummatory (outcome) components of reward processing; 2) a Go/No-Go Task that measures the ability to inhibit response to a pre-potent stimulus; 3) an Alcohol Cue Reactivity Task that examines Nucleus Accumbens response to alcohol-related versus matched soft drink stimuli; and 4) a Pavlovian-to-Instrumental Transfer (PIT) Task that dissects a component of the Monetary Incentive Delay (MID) Task, and provides an imaging assay of a transfer-like process that can be related to real-world drinking behavior, thus informing upon and extending the key findings from CTNA-2.

Detailed description:

Arms:
arm 1: Memantine is a low-side-effect NMDA receptor antagonist usually administered therapeutically to elderly persons with moderately severe Alzheimer's disease in typical doses of 10-20 mg daily. In this study, single doses of 40 mg are administered. arm 2: Memantine is a low-side-effect NMDA receptor antagonist usually administered therapeutically to elderly persons with moderately severe Alzheimer's disease in typical doses of 10-20 mg daily. In this study, single doses of 40 mg are administered. arm 3: Memantine is a low-side-effect NMDA receptor antagonist usually administered therapeutically to elderly persons with moderately severe Alzheimer's disease in typical doses of 10-20 mg daily. In this study, single doses of 40 mg are administered. arm 4: Memantine is a low-side-effect NMDA receptor antagonist usually administered therapeutically to elderly persons with moderately severe Alzheimer's disease in typical doses of 10-20 mg daily. In this study, single doses of 40 mg are administered.

Interventions: intervention 1: Memantine intervention 2: Placebo
Intervention descriptions: intervention 1: Memantine is a low-side-effect NMDA receptor antagonist usually administered therapeutically to elderly persons with moderately severe Alzheimer's disease in typical doses of 10-20 mg daily. In this study, single doses of 40 mg are administered. intervention 2: Identically appearing sugar pill, given orally

Protocol document: