The effect of ingesting varying quantities of alcohol upon the structure and function of the brain was studied using CT scan and psychometric testing. Nutritional status was also assessed. Alcoholics, heavy, moderate and light social drinkers were examined and their results compared with a normal control series. It was concluded that a daily consumption of more than 40 grams alcohol per day, "the safe level" results in brain damage. The latter may partially reverse with abstinence and having reversed maintain improvement, even though patients then resume drinking at the "safe level". The role of thiamin in brain function is still unclear.