Overall, this is a very accurate claim. The article derived from People.com is supported by a neurological study.
This quote from the study from the Academic Academy of Neurology states that "Researchers also found heavy and former heavy drinkers had higher odds of developing tau tangles, a biomarker associated with Alzheimer's disease, with 41% and 31% higher odds, respectively." which indicates that 8 alcoholic drinks a day does not mean that it is certain that an individual will develop dementia, but it is statistically likely that they will due to repetitive detrimental behavior.
According to nih.gov, it is strongly correlated that alcohol deteriorates the brain and causes shrinkage. "Heavy drinking accelerates shrinkage, or atrophy, of the brain, which in turn is a critical determinant of neurodegenerative changes and cognitive decline in aging”
https://pmc.ncbi.nlm.nih.gov/articles/PMC6705707/