Drug addiction is a condition in which a person develops a compulsive habit of taking drugs. An addict is unable to control the use of drugs. He continues to have the drugs, despite being aware of the harm they cause. People become addicts because of various reasons. Initially, it may be voluntary, out of curiosity, to have a good time, or to ease problems such as stress and depression. Some people take drugs to improve athletic performance. Once a person starts having problems at a physical, mental, and social level due to drug intake, it is a clear indication of drug addiction. Drug addiction makes a person dull, lacking in energy and motivation. People are mostly addicted to alcohol, cocaine, morphine, heroin, marijuana, hallucinogens (LSD, PCP), and crystal meth.