The results are reported by researchers at the San Francisco VA Medical Center and the University of California, San Francisco.
“This finding may indicate some kind of resilience factors are operating among the abstainers, or vulnerability factors among the relapsers,” says lead author Timothy Durazzo, PhD, an SFVAMC researcher and an assistant adjunct professor of radiology and biomedical imaging at UCSF. “Further study is necessary to understand the nature of the pattern of results we observed.”
The study appears in the March 2010 issue of the “Journal of Studies on Alcohol and Drugs.”
The study authors used magnetic resonance imaging to measure n-acetyl aspartate (NAA), an indicator of neuronal integrity, and creatine, which indicates cell metabolic integrity, in several regions of the brain known collectively as the “brain reward system.”
“Together, these brain regions are involved with reasoning, planning, judgment, impulse control, and anticipation and processing of pleasure,” explains Durazzo. “It’s the system that helps us weigh the pros and cons of our actions and then change our behavior based on the consequences.”
The researchers followed 51 individuals diagnosed with alcohol dependence who entered an outpatient alcohol treatment program, matched with 26 light-drinking control subjects. NAA and creatine were measured within four to ten days after the drinkers entered treatment.
One year later, the researchers looked at who among the alcoholics had stayed sober and who had relapsed, and compared their admission MRI data with that of the controls. They found that at the time of admission to treatment, the future relapsers had NAA and creatine levels that were significantly lower compared with both the controls and the future abstainers, while the abstainers’ levels did not differ from those of the controls.
“This study adds to the accumulating evidence that there are structural and biochemical abnormalities in the brain reward system in people who have chronic problems with substances and alcohol,” says principal investigator Dieter Meyerhoff, Dr. Rer. Nat., senior researcher at SFVAMC and professor of radiology and biomedical imaging at UCSF.
Durazzo notes that the majority of both the abstainers and the relapsers had been in treatment for drinking at least once before. “So, there are a number of questions to answer,” he says. “What, if anything, was different this time for the abstainers at the time they entered treatment? Had their brain neurobiology changed since their last treatment? Looking at the relapsers – did they have these biochemical abnormalities before they even started drinking at hazardous levels? Has chronic hazardous drinking interacted with a potential genetic predisposition to keep them locked into a chronic pattern of relapse? This will be addressed in future research.”
Alcohol and substance dependence are extremely complex issues, says Durazzo. “Speaking broadly, there are always social, cognitive, psychiatric, and biological issues that contribute to alcohol and substance abuse, and they interact differently in each individual. This study of the potential biological factors is simply one piece of a much larger puzzle that we’re just starting to fill in.”
Ultimately, he says, “the hope is that if we better understand the biological factors related to relapse, we can combine this information with knowledge of a patient’s social, cognitive, and psychiatric functioning to more thoroughly evaluate his or her risk of relapse. This may allow us to better tailor treatments.”
Co-authors of the study are Varsha Pathak, MD, of SFVAMC, Stefan Gazdzinski, PhD, of SFVAMC and UCSF at the time of the study, and Anderson Mon, PhD, of SFVAMC and UCSF.
The study was supported by funds from the National Institute on Alcohol Abuse and Alcohol and the National Institute on Drug Abuse, some of which were administered by the Northern California Institute for Research and Education.
NCIRE – The Veterans Health Research Institute – is the largest research institute associated with a VA medical center. Its mission is to improve the health and well-being of veterans and the general public by supporting a world-class biomedical research program conducted by the UCSF faculty at SFVAMC.
SFVAMC has the largest medical research program in the national VA system, with more than 200 research scientists, all of whom are faculty members at UCSF.
UCSF is a leading university dedicated to promoting health worldwide through advanced biomedical research, graduate-level education in the life sciences and health professions, and excellence in patient care.