Damage to the brain caused by alcohol continues during the first few weeks of abstinence, a finding that refutes the notion that the brain begins to normalize immediately after individuals stop drinking.
“Until now, nobody could believe that in the absence of alcohol the damage in the brain would progress,” study investigator Santiago Canals, PhD, of the Institute of Neuroscience of Alicante, Consejo Superior de Investigaciones Científicas–Universidad Miguel Hernández, Spain, said in a news release.
The study was published online April 3 in JAMA Psychiatry.
A Look Inside the Brain
Using diffusion tensor imaging, the researchers assessed microstructural alterations in white matter after long-term alcohol exposure and during early abstinence in 91 men (mean age, 46) who had alcohol use disorder (AUD).
The men were hospitalized and were undergoing detoxification treatment, which guaranteed that they did not drink alcohol. Thirty-six healthy men of similar age who did not have AUD served as control persons.
The researchers found diffuse microstructural changes in white matter in the men with AUD compared with the control persons. These changes primarily affected the right hemisphere and the frontal region of the brain. These changes progressed during 2 to 6 weeks of abstinence.
“The study was not designed to look further in time, also due to the fact that our results were unexpected,” study coinvestigator Wolfgang Sommer, MD, PhD, of the University of Heidelberg, Germany, said.
“Other studies looked at a longer time horizon and typically found signs of recovery, both of the brain structure and its function. Nevertheless, we need more research to understand what is going on here and what are the temporal aspects of the underlying phenomena,” said Sommer.
The researchers replicated their observations in an established rat model of excessive alcohol consumption.
“The fact that the findings in humans mirror those in rats may establish a relationship between the observed changes and alcohol consumption, which is difficult to verify based on human results only, given the large heterogeneity of the abuse patterns, medication for relief of withdrawal symptoms, and comorbidities among patients with AUD,” the researchers write.
“This result establishes the utility of diffusion imaging for monitoring the brain status as a possible noninvasive biomarker of AUD progression and, potentially, of treatment response,” they add.
Important Translational Study
“These types of translational studies are crucial to help fill in gaps in addiction research,” Marisa Silveri, PhD, director of the Neurodevelopmental Laboratory on Addictions and Mental Health, McLean Hospital, Belmont, Massachusetts, and associate professor of psychiatry at Harvard Medical School, Boston, said.
“The findings do fly a little in the face of what we know, because when people become abstinent, it usually doesn’t take them long for things like brain chemistry and cognition to improve, somewhat after abstinence. But it’s studies like these that uncover some more micro level cellular indicators that tell us that just because you can recover some function, it doesn’t necessarily mean the brain is returned to a healthy state,” said Silveri.
“That’s an important message because people often think that when they no longer feel the acute intoxicating effects of alcohol, that it’s not still having an effect, and we do know from many studies that there are residual effects of alcohol intoxication on neurobiology.
“The brain is a fantastic orchestra of networks, and understanding some of the subtler changes and what they mean is work that is most needed,” she added.