http://scienceu.fsu.edu/content/toba...lth/brain.html

"Heavy cigarette smokers thus appear to be true addicts, showing not only social habituation but . . . physiologic withdrawal effects. . . . concerns about the dangers of smoking, latent but readily mobilized in our population, are effectively masked by denial and related psychic defenses."
A classic symptom of "severe brain damage" was evident: "distorted time perception," e.g., "time moving slowly."

Thus, "our evidence at least is consistent with the existence of 'chronic intoxication' in the heavy smoker, which is harmful to the smoker himself."—Peter H. Knapp, Charles M. Bliss, Harriet Wells, "Addictive Aspects in Heavy Cigarette Smoking," 119 Am J Psychiatry 966-972 (April 1963). [More by Knapp; more on tobacco intoxication]