Some drugs lead to an unhealthy dependency that has both physiological and behavioral roots. The mind is our most important tool. With our mind, we solve the problems we face in life. Drugs do several things that harm one's ability to think or to be fully aware of the present surroundings. These effects continue long after the effects of the drug appear to have worn off.
Addictive drugs activate the brain's reward systems.
The promise of reward is very intense causing the individual to crave the drug and to focus their activities around taking the drug. The ability of addictive drugs to strongly activate brain reward mechanisms and their ability to chemically alter the normal functioning of these systems can produce an addiction. Drugs also reduce a person's level of consciousness, harming the ability to think or be fully aware of present surroundings. Because of the effects of drugs on the mind, a person with a history of drug use isn't quite tracking with what is going on around him. The drug taker is not moving in the same series of events as others.