Dennis E. McChargue

Impulsivity and smoking relapse

Previous research has shown that elevated trait-impulsivity heightens the risk for initiating tobacco use and indicates that nicotine may be disproportionately rewarding for more impulsive persons. However, the influence of impulsivity on the ability to maintain nicotine abstinence has not been studied. The present study tested the hypothesis that a higher level of trait-impulsivity would predict a more rapid relapse to smoking following 48 hr of nicotine abstinence. Participants were euthymic, regular smokers (N=45), with a history of at least one major depressive episode, who participated in a paid smoking cessation study with biological challenge (tryptophan depletion). Treatment involved a 1-day skills training workshop followed by 48 hr of bioverified abstinence and weekly follow-up for 1 month. Regression analyses indicated that elevated impulsivity predicted shorter time to relapse following the workshop after controlling for treatment condition, baseline nicotine dependence, and age (beta=-.39, R(2) change=.147, p=.011). Greater impulsivity predicted more rapid relapse to smoking, which mediational analyses indicated could not be explained by positive affect, negative affect, or craving. Findings suggest a need to identify alternative mechanisms to explain impulsive smokers increased difficulty in maintaining abstinence and to develop targeted treatments that address the special needs of smokers high in impulsivity.

Effect of impulsivity on craving and behavioral reactivity to smoking cues

IntroductionNearly 25% of American adults remain regular smokers. Current smokers may be especially likely to possess characteristics that impair their ability to quit, such as impulsivity. Impulsive individuals may be overly prone to smoke because they are particularly drawn to rewarding stimuli and related cues. The aim of this study was to test the hypothesis that more impulsive smokers are more responsive to cigarette cues than other smokers.Materials and methodsIn a repeated measures design, 60 euthymic, adult smokers (50% female) were exposed to a smoking cue and a neutral cue in two experimental sessions. Cue reactivity was operationalized as changes in cigarette craving and preference for immediate vs delayed smoking after cue exposure.ResultsImpulsivity predicted a heightened craving response to both cues but particularly the smoking cue (t [161]u2009=u20093.21, pu2009=u20090.002). Smokers with high levels of impulsivity exhibited a greater preference for immediate rewards over larger, delayed rewards in terms of both hypothetical (t [58]u2009=u20095.99, pu2009=u20090.001) and actual (zu2009=u20093.02, pu2009=u20090.003) rewards.ConclusionThese data suggest that increased reactivity to environmental smoking cues contributes to the link between impulsivity and smoking.

Hedonic capacity, cigarette craving, and diminished positive mood

Cigarette craving has been linked to elevated negative and positive moods, but a connection to deficient positive affect has not been studied. We tested whether a low hedonic capacity predicts a heightened urge to smoke after acute nicotine deprivation, and whether such an effect is mediated by decreased positive mood or increased negative mood. A total of 35 smokers characterized for individual differences in hedonic capacity were deprived of nicotine for 48 hr. Using mixed-effects regression modeling, we found that lower hedonic capacity predicted greater increases in craving 24 hr after nicotine withdrawal, t(29)=-2.33, p=.03. The effect of hedonic capacity on increased 24-hr postquit craving to smoke was fully mediated by decreased positive affect. Findings suggest that in early nicotine withdrawal, smokers with diminished capacity to experience pleasure have heightened susceptibility to cigarette cravings that arises because of decreased positive mood rather than increased negative mood.

Altered reward value of carbohydrate snacks for female smokers withdrawn from nicotine

Discontinuing nicotine intake usually results in weight gain partially due to heightened energy intake from between-meal snacks. This experiment tested the hypothesis that the reinforcing value of palatable carbohydrate-rich snacks increases for female smokers during nicotine deprivation. Eighteen smokers and 18 nonsmokers completed a concurrent-schedules operant computer task on two separate days. Smokers were bioverified abstinent at the second testing. The operant task allowed participants to earn points redeemable for either carbohydrate snacks or money on concurrent variable-ratio schedules of reinforcement. There were five different probabilities of earning points redeemable for snacks (8%, 16%, 25%, 50%, 75%), while the probability of earning points redeemable for money remained fixed at 25%. Reward value of snacks was measured by switch point: the reinforcement ratio at which the effort required to earn snacks exceeded their value to the respondent, as signified by a shift to working for money. Results showed that smokers undergoing nicotine deprivation persisted in working for snacks into leaner reinforcement schedules than nonsmokers (P=.026). Furthermore, nicotine deprivation increased smokers allocation of effort to earn snack foods relative to their own behavior when smoking (P=.006). Variation in palatability or hunger did not explain these differences in snack reward value. Findings indicate that nicotine deprivation is associated with a heightened reward value of appealing snack foods for female smokers.

Effect of nicotine on negative affect among more impulsive smokers.

In the present study, the authors tested the hypothesis that nicotine would provide greater relief from negative affect for more impulsive smokers than for less impulsive smokers. Euthymic adult smokers (N=70) participated in 2 laboratory sessions, during which they underwent a negative mood induction (music + autobiographical memory), then smoked either a nicotinized or de-nicotinized cigarette. Mixed-effects regression yielded a significant Impulsivity x Condition (nicotinized vs. de-nicotinized) x Time interaction. Simple effects analyses showed that heightened impulsivity predicted greater negative affect relief after smoking a nicotinized cigarette but not after smoking a de-nicotinized cigarette. These data suggest that nicotine may be a disproportionately powerful negative reinforcer for highly impulsive smokers, promoting higher levels of nicotine dependence and inhibiting smoking cessation.

The influence of personality and affect on nicotine dependence among male college students.

Many clinicians and researchers hypothesize that tobacco use disorders, regardless of the route of administration, are maintained by the ability of nicotine to regulate positive and negative mood states. The present study (N=137) examined whether certain mood states predicted dependence on either cigarettes or smokeless tobacco and whether specific personality characteristics (e.g., extraversion, neuroticism, and psychoticism) mediated these relationships among young male college students. Results indicated that positive and negative moods predicted cigarette dependence (p values=.01) and that neuroticism partially mediated the relationship between positive affect and cigarette dependence. Exploratory analyses revealed that positive affect also interacted with neuroticism to predict smokeless tobacco dependence (p=.04). Simple effects analyses revealed that this relationship was maintained only among individuals high in neuroticism. Results suggested that dependence on cigarettes and smokeless tobacco among male college students may have different affective correlates and that certain personality characteristics may enhance and explain the effects of mood on tobacco dependence.

Fluoxetine, Smoking, and History of Major Depression: A Randomized Controlled Trial

The study was a randomized placebo-controlled trial testing whether fluoxetine selectively enhances cessation for smokers with a history of depression. Euthymic smokers with (H+, n = 109) or without (H-, n = 138) a history of major depression received 60 mg fluoxetine or placebo plus group behavioral quit-smoking treatment for 12 weeks. Fluoxetine initially enhanced cessation for H+ smokers (p = .02) but subsequently impaired cessation regardless of depressive history. Six months after quit date, fluoxetine-treated participants were 3.3 times more likely to be smoking (p = .02). Further research is warranted to determine why high-dose fluoxetine produces continuing effects that oppose tobacco abstinence.

Rumination and cigarette smoking: A bad combination for depressive outcomes?

Ruminative coping has been shown to heighten the risk and severity of depression. The authors hypothesized that ruminators who smoke would experience greater depressive symptoms than ruminators who do not. The rationale is that, by heightening attentional focus, nicotine may increase ruminators ability to focus on negative thoughts, augmenting depressed mood. Participants (N = 145) self-reported smoking status, rumination, and current and lifetime depressive symptoms, including depressed mood. Results showed that rumination accounted for a larger amount of variance in current and past depressed mood and severity of lifetime depressive symptoms among smokers than nonsmokers. Noncorrelational, experimental research should directly test whether nicotine worsens depressed mood among ruminative smokers. Such evidence would be surprising because it would contradict the assumption that nicotine dispels negative moods.

Elevated positive mood: a mixed blessing for abstinence.

The present study, a secondary analysis of published data, assessed (a) the influence of initial positive mood (PM) on smoking cessation and (b) whether smokers low in PM benefited from fluoxetine versus placebo for cessation. Euthymic adult smokers (N = 103) received 10 weeks of cessation treatment. Analyses showed a Time x PM interaction, indicating that higher baseline PM predicted decreased abstinence during treatment but increased abstinence afterward, mediated by time to dropout. Dichotomous initial PM interacted with drug, suggesting a benefit of fluoxetine for low-PM smokers. Results indicate that lower pretreatment PM may inhibit long-term cessation. Smokers with lower baseline PM may benefit from treatment that increases PM.

Multimodal assessment of the effect of chewing gum on nicotine withdrawal.

The present study was designed to evaluate the usefulness of chewing gum to reduce nicotine withdrawal, craving, and salivary cortisol concentrations during temporary nicotine deprivation. A total of 20 male smokers were studied under conditions when gum was and was not accessible during a 4-hour deprivation period. All subjects smoked an initial cigarette shortly after arrival for the two experimental sessions and were informed that they would be unable to smoke for the remainder of each session. The sessions consisted of each subject watching a movie, then waiting in the lab for two consecutive 30-min intervals. Self-reported nicotine withdrawal and craving were assessed four times and salivary cortisol five times during each experimental session. Results from this study indicate that chewing gum helps with self-reported withdrawal but not craving when a smoker is prevented from smoking. This study also provides preliminary data on the use of salivary cortisol as a physiological marker that may map these self-reports of nicotine withdrawal and craving.