Alcohol is a depressant, which means that even small amounts of alcohol slow down the actions of parts of the brain, so alcohol lengthens the time you take to respond to a stimulus.
Different people react differently to alcohol. In some people, it increase their feelings of aggression, and releases their inhibitions so that they are more likely to be violent or commit other crimes.
An alcoholic needs to drink quite large quantities of alcohol regularly. This causes many parts of the body to be damaged, because alcohol is poisonous to cells. Probably, there are many factors which decide whether or not a person becomes alcoholic. Over a long period of time, it can cause loss of memory and confusion. One way in which the damage is done is that alcohol in the body fluids draws water out of cells by osmosis.
Effect of alcohol on cells is -

1. A Swelling of cells
2. B Shrinking of cells
3. C Bursting of cells
4. D Reduction in cell number