Nicotine withdrawal exacerbates fear reactivity to CO₂-induced bodily sensations among smokers.

Independent lines of research suggest that smoking increases the prospective risk of panic disorder. Studies that have examined the hypothesized link between nicotine withdrawal and panic have typically employed light smokers or lacked optimal control groups. Our laboratory team previously found, for example, that smokers who abstained from cigarettes for 12 hr demonstrated greater fear reactivity to a CO(2) rebreathing challenge than nonsmokers. However, the absence of a smoking-as-usual group limited our ability to draw conclusions about the potential role of nicotine withdrawal. We exposed 27 heavy smokers who abstained from smoking for 12 hr and 27 heavy smokers who smoked as usual to a 5-min CO(2) rebreathing challenge. More intense prechallenge nicotine withdrawal symptoms (regardless of group status) were associated with more severe panicky symptoms and a stronger urge to escape during the challenge, even after we controlled for prechallenge anxiety and daily cigarette use. Unexpectedly, group status did not predict challenge reactivity. Smokers who regularly experience intense withdrawal symptoms, regardless of length of smoking abstinence, may be at heightened risk for experiencing panic attacks.