Are some of us more prone than others to drug addiction and alcohol dependence?

Drug, alcohol addict: Some of us have adverse reaction to pain medications or alcohol use, while others find one or both extremely pleasurable, thus reinforcing continued and repeated use. These are due to differences in the chemistry of the brain, often a genetic effect. If others in your family have addictions, better to not try these substances, as risk an addiction!

Prone to drugs?: The same gene makes you prone to both drugs and alcohol. Kids of alcoholic, even if they do not become alcoholic, has the same gene their parents have, and can digest massive amount of booze while their friends can only take a limited amount. Cannot be alcoholic if no posession of genes that allow presence of massive amount of enzymes to digest big quantity of alcohol. Same with drugs!