New research shows how rapidly the brain can mend its structure when drinking stops, which is good news for patients recovering from alcohol use disorder. People with alcohol use disorder (AUD) have cortical thinning, which is the wrinkled outer layer of the brain that is crucial to many higher-order cognitive tasks. The study in the United States discovered that those who stop drinking develop cortical thickness over time, faster in the first month and continuing for 7.3 months, at which point thickness is comparable to those who do not drink. A previous study showed that when someone quits drinking, some regions may recover, but it was unknown how much or how rapidly recovery happens.
“The few longitudinal studies investigating cortical thickness changes during abstinence are limited to the first month of sobriety,” writes the team, led by psychiatrist and behavioral scientist Timothy Durazzo from Stanford University. “However, the extent of regional cortical thickness recovery over an extended period of abstinence (e.g., greater than 6 months) is unknown.” An estimated 16 million people in the US suffer from AUD. It’s a major public health issue, and understanding this complex disorder is important for treatment, prevention, and reducing stigma.
They also examined 45 people who had never had AUD, assessing their cortical thickness at baseline
Changes in brain structure and function caused by chronic alcohol consumption might make it difficult for people to stop drinking, despite their best efforts. For example, the prefrontal cortex, which is important in planning and decision-making, may become less active, making it more difficult for people with AUD to make appropriate choices. Durazzo and colleagues also investigated how certain health factors, smoking history, psychological diseases, and substance use disorders affect long-term cortical thickness changes in AUD recovery patients.
In total, 88 patients with AUD took part in the study, with brain scans performed after one week, one month, and 7.3 months of abstinence. Because some participants joined at the one-month mark, 23 individuals did not have scans performed at the one-week mark, and only 40 of the total 88 continued to abstain from alcohol for the entire period. They also examined 45 persons who had never had AUD, assessing their cortical thickness at baseline and then roughly 9 months later to ensure the areas evaluated were the same.
The individuals’ brains were examined using a sort of magnetic resonance imaging (MRI) that is particularly useful for obtaining clear images of the body’s interior structure. The researchers measured cortical thickness in 34 areas of the brain, averaging the results across the left and right hemispheres. Recovery of thickness was widespread in those with AUD after 7.3 months without alcohol. It was sufficient to be statistically significant in 25 of the 34 locations, with 24 of them being statistically equal in thickness to controls. Durazzo and his colleagues observed a faster rate of thickness change in AUD participants from 1 week to 1 month after quitting than from 1 month to 7.3 months.
Cortical thickening occurred more slowly in various areas of the brain of AUD patients who also had high blood pressure or high cholesterol
Cortical thickening occurred more slowly in various areas of the brain of AUD patients who also had high blood pressure or high cholesterol. The same was true for AUD patients who were current smokers. There were no significant associations between cortical thickness changes and current substance usage (including drugs other than alcohol), psychiatric problems, or previous cigarette smoking. As a result, stopping smoking may aid in the recovery of cortical thickness. These findings bring hope and a new understanding of brain healing after alcohol withdrawal, albeit they may not be generalizable due to the limited sample size and lack of diversity. It’s also worth noting that these findings don’t say anything about whether the modifications had any influence on brain function.
“Larger longitudinal studies are required to examine the neurocognitive and psychosocial correlates of cortical thickness recovery during sustained abstinence in AUD,” the team writes. The authors also point out that variables they didn’t account for, such as genetics, physical activity, and people’s liver and lung health, could have affected their findings. “This data provides clinically relevant information on the beneficial effects of sustained sobriety on human brain morphology,” the authors conclude, “and reinforces the adaptive effects of abstinence-based recovery in AUD.”