Most people who develop alcohol use disorders do so by their late 30s. However, an alcohol use disorder may emerge at any time during the lifespan. Genetics heavily influence whether someone develops problems with alcohol. In fact, genetics account for about 50% of the variance. If you have several relatives with severe alcohol problems, your genetic risk may be quite high (APA, 2000). Different people respond to alcohol differently. Some people require more alcohol to produce intoxication. Some of this difference seems to be genetically determined.
The repeated use of alcohol by pregnant women may lead to fetal alcohol syndrome (FAS). FAS is characterized by devastating, physical and behavioral defects in infants such as intellectual disabilities, stunted growth; limb malformation; heart problems; and delayed motor development. These defects are usually not reversible. Heavy alcohol use often leads to tolerance and withdrawal.