Because they continue to work and socialize reasonably well, their deteriorating physical condition may go unrecognized by others until severe damage develops - or until they are hospitalized for other reasons and suddenly experience alcohol withdrawal symptoms. Psychological dependence on alcohol may occur with regular use of even relatively moderate daily amounts. It may also occur in people who consume alcohol only under certain conditions, such as before and during social occasions. This form of dependence refers to a craving for alcohol's psychological effects, although not necessarily in amounts that produce serious intoxication. For psychologically dependent drinkers, the lack of alcohol tends to make them anxious and, in some cases, panicky.
Physical dependence occurs in consistently heavy drinkers.
Since their bodies have adapted to the presence of alcohol, they suffer withdrawal symptoms if they suddenly stop drinking. The most serious of these effects include mental retardation, growth deficiency, head and facial deformities, joint and limb abnormalities, and heart defects. While it is known that the risk of bearing an FAS-afflicted child increases with the amount of alcohol consumed, a safe level of consumption has not been determined. More than one in five of all those who drank said they did so more than once a week. Since the legal drinking age in Ontario is 19, it appears that alcohol has a high degree of social acceptance, whether legal or not.