Study Shows Widespread Brain Damage in Alcoholics
While the idea that alcohol negatively affects the brain has been around for a long time, before advances in neuroimaging, it wasn’t known how quantity and quality of drinking came into play. This new study shows that “alcohol has wide-ranging effects across the entire cortex and in structures of the brain that contribute to a wide range of…functions,” Dr. Fortier says.
The brain consists of two types of tissue: grey matter (neurons) of the cortex and white matter (axons), which make up the connecting tissue. Electrical signals travel from neuron to neuron via axons, and this is how brain cells communicate with each other. Excessive drinking can damage both grey and white matter.
In the study, scientists used high-resolution structural magnetic resonance imaging (MRI) on 31 abstinent alcoholics with an average of 25 years use and about 5 years sobriety, and compared their white matter tracts to 20 healthy light-drinking controls. They found widespread reductions in white matter on both sides of the brain and in multiple regions, including the frontal, temporal, parietal and cerebellar lobes.
The region that was the most damaged included the frontal and superior white matter tracts. “Frontal white matter tracts are the pathways that connect the frontal lobes to the rest of the brain,” Fortier says. “Frontal pathways underlie impulse control, which is essential to achieve and maintain abstinence.”
With the greatest impact of excessive alcohol use being on the white matter of the frontal lobes, this explains why alcoholics lose their ability to control how much they drink. These areas are also crucial for learning, self-regulation, impulse control and changing behaviors in light of this new information. “In other words, the very parts of the brain that may be most important for controlling problem drinking are damaged by alcohol,” Fortier says.
Not only was white matter diminished across the entire brain, but also the effect of drinking seems to depend on dose. Fortier compares excessive drinking to sunburn: The damage will vary depending on the severity of exposure. “Pathology is often thought of as occurring as an all or none phenomenon,” she says. “Alcohol, however, is more like sunburn. Our study shows that…the more you drink, the greater the damage to key structures of the brain, such as the inferior frontal gyrus, in particular. This part of the brain mediates inhibitory control and decision making, so damage here likely results in impulsive behavior and inability to say ‘no’ to the next drink.”
Alcohol Recovery: Regaining Brain Volume
But there’s good news: Lost grey and white matter can be recovered. According to a recent study from scientists at the University of California-San Francisco (UCSF), they found that both grey and white matter improve with abstinence.
In this study, published online in the journal Addiction Biology in August 2014, the researchers found “significant increases in both cortical gray matter and white matter volume during approximately 7.5 months of abstinence,” says lead author Timothy Durazzo, PhD, an associate professor at UCSF and affiliated with the Center for Imaging of Neurodegenerative Diseases. Most changes occurred during the first month. “This may suggest that the adaptive ‘plastic’ changes in gray matter volume occur soon after cessation of alcohol consumption, which is certainly encouraging for those individuals seeking treatment to achieve and maintain sobriety,” he says.
In the UCSF study, however, even though grey matter increased, except in the frontal cortex, it didn’t recover to the same level as non-drinkers’ at the end of the follow-up period. Dr. Durazzo is hopeful that longer follow-up time might reveal a greater level of recovery among former drinkers.
In Fortier’s study, it was found that white matter could possibly be recovered in the left inferior frontal gyrus, but only in people who stopped drinking before their fifth decade of life. This might be a “critical threshold,” she says. If a person continues drinking, permanent brain damage after age 50 “can result in behavioral problems taking the form of impulsivity, difficulty with self-monitoring, judgment, planning, reasoning, poor attention span, inability to alter behavior, and a lack of awareness of inappropriate behavior,” Fortier says.
Fortier believes that both grey and white matter can be recovered to some extent with abstinence, and that increasing brain volume in areas related to self-control should be part of recovery treatment. “Additional training in behavioral control and problem solving could be helpful for successful rehabilitation and maintained abstinence,” she says.
Durazzo advises against smoking as well. “In several of our studies, we’ve found that cigarette smoking in people with an alcohol use disorder is associated with diminished biological and cognitive recovery, for example, learning and memory, problem-solving skills and processing speed.” And “a good diet, quality sleep, and cardiovascular exercise can’t hurt,” he adds.
By Jeanene Swanson
Follow Jeanene on Twitter at @JeaneneSwanson