In Chasing the Scream, the author argues that drug addiction is not caused by the chemicals in drugs but by an addict’s environment. The author uses the example of Bruce Alexander, who was a professor who realized that an experiment conducted by psychologists proving that drug withdrawals kills its users was incorrect. A group of scientists ran a study on rats that showed that rats in a confined environment exposed to drugs would continue using these drugs, which was so. But the scientists did not consider, that there was nothing for these rats but being confined in a cage alone with just drug infested water. Bruce remade the previous experiment using a second environment as well as the original environment, the second setting was a rat paradise which also including the drug morphine and added the same drug addicted rats to the rat paradise known as “rat park”. To their amazement, the drug addicted rats broke their drug habit and showed symptoms of withdrawal but never went back to consuming the drugs in the environment. This proved the theory, that drug addicts are not addicted to drugs because of their chemicals but because of their environment and the habits. The was also the example of the Vietnam War, a study showed that 20 percent of U.S Soldiers had become addicted to heroine, but once back in the United States, 95 percent of the soldiers did not continue the use of drugs. The five percent who did not kick their bad habits were already addicts before deploying or had bad childhoods. In conclusion, the author learned that there is a difference between physical dependence and addiction. Physical dependence has to do with chemicals, and addiction is a psychological feeling for a need for the sensation of being calm or whatever sense of feeling it actually gives off.