SPECT studies: damage from substance abuse is immediately apparent. The normal brain is smooth, symmetrical, and full.

(Amen, Daniel G., MD. Change Your Brain Change Your Life. p 242-245. NY:Times Books, 1998.)

Drugs, legal and illegal, can interrupt feedback loops that allow the psychosomatic network to function in a natural, balanced way. They can set up conditions for somatic and mental disorders. (Pert, Candace, PhD. Molecules of Emotion. p 273-274. NY:Scribner, 1997.)

Studies at UC San Francisco: Addiction is caused by more than the pharmacological effects of a given drug, Drug addiction is a life-long disease. Although drug-taking behaviors may be absent, the ‘memory’ makes relapse not only possible but likely. (Science News. Cocaine Addiction Linked To Voluntary Drug Use And Cellular Memory, Study Shows. 2008 likely.