Joseph P. Schacht, Ph.D.
Dr. Joseph Schacht joined the Center for Drug and Alcohol Programs (CDAP) in 2009 as a pre-doctoral psychology intern. Today he is a post-doctoral fellow in the Department of Psychiatry and Behavioral Sciences at the Medical University of South Carolina (MUSC), under the mentorship of Dr. Raymond F. Anton, Director of CDAP. Dr. Schacht received his PhD in clinical psychology and neuroscience from the University of Colorado, Boulder and completed his clinical internship at the Charleston Consortium, a collaborative training program between MUSC and the Ralph H. Johnson VA Medical Center.
Dr. Schacht's research at CDAP uses neuroimaging to understand how alcoholism and other addictive disorders change the brain, as well as how brain changes may predict who is at risk for developing these disorders and who may benefit from treatments for them. Below is a description of Dr. Schacht's ongoing work in this area.
Alcohol Craving in the Brain
Through a process called classical conditioning, stimuli that usually accompany alcohol use, such as the sight of one's favorite beer label or the taste of one's favorite liquor, become associated with the pleasurable, positively reinforcing effects of alcohol. These stimuli are known as "cues". Among people with problematic alcohol use, alcohol-related cues can cause craving, or an intense urge to drink. Among people who are trying to cut down or quit drinking, craving can lead to relapses. Dr. Schacht uses a kind of neuroimaging called functional magnetic resonance imaging (fMRI) to study how these cues affect the brain. The colored areas of the image below reflect parts of the brain that are more active when people with alcohol use disorders are exposed to alcohol-related cues. Interestingly, many of these brain areas are part of the brain's reward system, which, under normal circumstances, uses the neurotransmitter dopamine to signal that a stimulus (i.e., food, sex) is rewarding and should be pursued. The fact that alcohol cues, rather than just alcohol itself, can activate this system among individuals with alcohol use disorders suggests that exposure to these cues may hijack reward-related processing and drive an individual to seek alcohol
Brain Networks and the Development of Alcoholism
Dr. Schacht is currently using fMRI and structural neuroimaging, including a new technique called diffusional kurtosis imaging, to capitalize on and advance the basic finding that alcohol cues activate areas of the brain reward system. He is particularly interested in the manner in which these brain areas are connected to each other. While older models of the brain conceived of it as a set of independent areas that interacted sparingly, newer research suggests that these areas interact with each other in circuits, and that changes in the strength of these circuits may underlie addiction and other brain diseases. People with alcohol use disorders often progress from drinking for reward, which is characterized by gaining tolerance to the effects of alcohol and finding oneself drinking more or for a longer period than one intended, to drinking out of habit, which is characterized by alcohol interfering with other responsibilities (work, family, school) and by giving up other activities in favor of drinking. Studies in animals suggest that different brain circuits are related to reward and habit. The image below shows what these circuits may look like in humans. Dr. Schacht recently submitted a research grant proposal to the National Institute on Alcohol Abuse and Alcoholism (NIAAA) to study brain circuit differences between people who drink for reward and those who drink out of habit. If he is able to obtain funding from NIAAA or other external sources, he hopes to stay at CDAP as an independent faculty member. His overarching goal is to use brain imaging to improve the diagnosis and treatment of alcohol and drug addiction.
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