The act of smoking—apart from actual or expected nicotine delivery—may soothe a smoker's negative mood. Dr. Kenneth A. Perkins and colleagues at the University of Pittsburgh showed 200 smokers combinations of images and music, some pleasant and others disturbing, to induce a good or bad mood. The study participants began smoking sooner and smoked more after the disturbing presentations than after the pleasant ones.
The participants reported that smoking alleviated their negative feelings, offset symptoms of nicotine withdrawal, and relieved cigarette craving. As in past research, their responses were similar whether they were given regular nicotine cigarettes or cigarettes with only trace amounts of nicotine. Strikingly, however, their responses were also similar when they recognized that the cigarettes contained almost no nicotine.
The team repeated the procedure with 20 smokers, this time giving them unlit cigarettes to handle and pretend to puff. These smokers reported no alleviation of their negative moods or craving.
Taken together, the two studies suggest that the sensory experience of smoke inhalation, but not nicotine, is critical to the acute emotional benefits of smoking experienced by chronic smokers and that these benefits accrue even when the smokers know they are getting almost no nicotine.
Journal of Abnormal Psychology 117(1):79-93, 2008. [Abstract]