Physical dependency is the ability of a human body to develop tolerance to a particular substance, which when the user abruptly stops taking results in withdrawal symptoms. An extreme form of habit, but the...

Drug is any substance which alters the normal functioning of the body. Drugs are mainly classified into three main categories – depressants, stimulants and hallucinogens, based on their effect on the central...

Habit is a behavior pattern developed by frequent repetition of the act over and over to the point the brain does it automatically. An addiction is a compulsive need of a certain thing or substance to the body...