No abstract

Smoking abstinence responses were characterized in 96 female smokers. Participants completed subjective state measures twice per week for 5 weeks and were then randomly assigned to a group required to abstain for 31 days or a control group that continued to smoke. Financial incentives for biochemically verified abstinence resulted in an 81% completion rate. Abstinence-related increases in depression, tension, anger, irritability, and appetite showed little tendency to return to prequit levels and remained significantly elevated above smoke-group levels. In contrast to psychological components of anxiety, physical components decreased to smoke group levels by the 2nd week of abstinence. Trait depression and neuroticism predicted larger increased abstinence-associated negative affect. The Big Five personality dimensions predicted variance not associated with depressive traits.

Changes in physiology and attentional performance associated with smoking abstinence were characterized in 67 female smokers during low-stress and high-stress conditions. Abstinence was associated with decreases in cognitive performance, heart rate, and electroencephalographic (EEG) activation but with no change in serum estradiol or progesterone. Effects of quitting showed no tendency to resolve across the 31 days of abstinence. EEG deactivation and heart rate slowing were greater during a math task (high stress) than during relaxation (low stress). Individuals high in trait depression or nicotine dependence or with at least one dopamine D(2) receptor A1 allele experienced greater EEG deactivation following abstinence, especially in the right hemisphere during the stressful task. Thus, findings support the situation x trait adaptive response model of abstinence effects and emphasize the value of multiple dependent measures when characterizing abstinence responses.

Changes in task-related mood and physiology associated with 31 days of smoking abstinence were assessed in smokers, 34 of whom were randomly assigned to a quit group and 22 to a continuing-to-smoke control group. A large financial incentive for smoking abstinence resulted in very low participant attrition. Individuals were tested during prequit baselines and at 3, 10, 17, and 31 days of abstinence. Abstinence was associated with decreases in heart rate and serum cortisol, a slowing of electroencephalogram (EEG) activity, and task-dependent and trait-depression-dependent hemispheric EEG asymmetries. Differences between the quit group and the smoking group showed no tendency to resolve across the 31 days of abstinence. Trait depression and neuroticism correlated with increases in left-relative-to-right frontal EEG slow-wave (low alpha) activity at both 3 and 31 days of abstinence. In contrast, prequit nicotine intake and Fagerström Tolerance scores correlated with alpha asymmetry and with greater EEG slowing only at Day 3. Thus, the effects of smoking abstinence appear to last for at least several months.

Effects of nicotine and caffeine, separately and in combination, were assessed in 12 male habitual smokers in a repeated-measures design. Caffeine (0-mg vs. two 150-mg doses administered in a decaffeinated/sugar-free cola drink post-baseline and 90 min later) was crossed with nicotine (ad libitum own dosing vs. 1.0-mg machine-delivered dose vs. 0.05-mg machine-delivered dose). Participants smoked a total of five cigarettes at 30-min intervals over a 2-hr period. Caffeine and nicotine had large effect sizes on electroencephalogram (EEG) power; however, these effects were modulated by the eyes open versus closed condition, the other drug, and electrode site. EEG effects of open versus closed eyes tended to be of the same size and direction as those of nicotine and caffeine. However, whereas nicotine increased EEG power in some higher frequency bands in some conditions, caffeine decreased EEG power across almost all conditions. Serum cortisol concentration, vigor, and pleasantness were increased by nicotine, but not by caffeine. Level of depressive mood depended on an interaction of caffeine and nicotine. Vigilance performance was enhanced significantly by caffeine and was increased almost significantly by nicotine. The findings were interpreted in terms of common and differential mechanisms of the two drugs.