Report investigates impact of smoking, alcohol on cerebellum and related cognitive function

There is consistent evidence that having an alcohol use disorder is associated with abnormalities in the cerebellum, a structure attached to the bottom of the brain that is involved in coordinating posture and balance but also in supporting some cognitive functions. Cigarette smoking, which often co-occurs with alcohol use, has also been shown to impact brain structure and function, and co-use of these substances is purported to accelerate aging of the brain. A report published in the journal Alcoholism: Clinical & Experimental Research examines neuroimaging (MRI) data from 92 people in order to further investigate the impact of smoking and alcohol status on the volume of the cerebellum and related cognitive function.

The participants included people with alcohol use disorder (some of them smokers) who were enrolled in treatment programs at health centers in California, and who had abstained from alcohol for on average of 3 weeks. Healthy individuals, again some of whom were smokers, were recruited locally for comparison. In addition to undergoing MRI brain scans, all study participants completed a series of neurocognitive tests, focusing on cognitive measures previously shown to be associated with cerebellar abnormalities.

Using novel cerebellar measurement software, the researchers showed that both alcohol dependence and chronic cigarette smoking were associated with reduced cerebellum volume, with some regions in the cerebellum more vulnerable to alcohol use and less affected by smoking. Smokers with alcohol use disorder had smaller cerebellar volumes than their non-smoking counterparts, providing further evidence that smoking can exacerbate cerebellar volume deficits in people with alcohol dependence. Preliminary analyses also showed that smaller cerebellar volumes were related to greater smoking severity, and that the observed cerebellar volume abnormalities were associated with lower intelligence. The longer the people with alcohol use disorders had abstained from drinking, however, the more the cerebellar abnormalities disappeared, suggesting brain recovery and benefits of alcoholism treatment in smokers.

The researchers note that studies with larger groups of patients are needed to further examine the specific interactions of heavy alcohol use and smoking on cerebellar structure, cognitive function and recovery, and that this type of research could lead to the development of more effective interventions for alcohol use disorder.