Overnight Abstinence Research Articles

Clonidine pre-treatment fails to block acute smoking-induced EEG arousal/mood in cigarette smokers

Given the arousal eliciting actions of smoking and nicotine, and the contributing role of noradrenaline in brain arousal systems, this study examined the neuroelectric and affective correlates of cigarette smoking following acute pre-treatment with the alpha 2-noradrenergic auto-receptor agonist, clonidine. In a double-blind placebo-controlled crossover design, quantitative electroencephalography (EEG), mood, and smoking withdrawal symptoms were assessed in 12 overnight smoking abstinence smokers, before and after sham and cigarette smoking. Orally administered clonidine (0.1 mg) failed to alter overnight smoking abstinence symptoms or the EEG arousal and mood-elevating response seen with the smoking of a single cigarette. The results are discussed in relation to neural mechanisms underlying the acute reinforcement maintaining nicotine use.

Neuroendocrinological and neuropsychological correlates of dopaminergic function in nicotine dependence.

There is multiple evidence that nicotine--as with ethanol and other drugs of abuse--stimulates dopamine release in the ventral striatum as a central part of the brain reward circuits. Chronic nicotine exposure leads to changes in these dopaminergic reward circuits. During nicotine withdrawal, an impaired dopaminergic function has been reported. On the behavioral level, this seems to result in motivational disturbances in abstaining smokers. To investigate the impact of smoking on dopaminergic function in humans both on a neuroendocrinological and on a neuropsychological level. Thirty-seven healthy smokers were assessed whilst smoking (test 1) and after abstaining overnight for 12 h (test 2). A control group of 18 non-smokers was also examined twice. Severity of nicotine dependence, incentive motivation, digit span and verbal fluency were assessed. The sensitivity of central dopamine (DA) D2 receptors was assessed with the apomorphine-induced growth hormone (GH) secretion. ANOVA revealed that GH response was significantly lower in smokers than in non-smokers (P=0.04). The GH response was significantly inversely correlated with severity of nicotine dependence (r=-0.39). Neuropsychological performance was not influenced by smoking status. After overnight abstinence from nicotine GH response, digit span and verbal fluency were not affected, whereas incentive motivation was significantly impaired in smokers (P=0.04). Smoking is significantly associated with a reduced sensitivity of central DA D2 receptors. This alteration of dopaminergic sensitivity is stable even after 12 h of abstinence from nicotine. Therefore, the hypothesis that the motivational impairment during withdrawal from nicotine is associated with an altered sensitivity of central DA D2 receptors cannot be supported.

Effects of tobacco smoking on electroencephalographic, auditory evoked and event related potentials

After overnight abstinence, tobacco smokers smoked an average nicotine yield cigarette and nonsmokers sham smoked an unlit placebo cigarette. EEG α 1, δ, and θ frequency amplitudes decreased, whereas α 2 and β frequency amplitude increased. Short, middle (EP) and long latency ERP were also studied in nonsmokers and smokers just after smoking, and after overnight abstinence from tobacco. Short latency potentials were unaffected by tobacco smoking or abstinence. Middle and long-latency potentials were reduced during abstinence and enhanced immediately after tobacco smoking. These findings indicate that compared to nonsmokers smokers have a higher arousal level after smoking than when partially abstinent. Evidence for both normalization from tobacco abstinence as well as stimulation was obtained.

Cigarette smoking and attention to signals of reward and threat in the Stroop paradigm.

To test the prediction arising from the incentive-sensitization model of addiction that when tested immediately after smoking, smokers will show heightened attention to words with appetitive and aversive motivational significance compared with their performance during acute abstinence. Twenty-one smokers were each tested twice, once just after smoking and once after overnight abstinence, on three versions of the modified Stroop task which required colour naming of words with either neutral, appetitive or aversive connotations. Ten non-smokers were tested once. All participants were tested in a quiet experimental cubicle within the psychology department. Smokers comprised nine men and 12 women who had smoked at least 10 cigarettes per day for the last 6 months; non-smokers comprised five men and five women who had never smoked. All were aged between 18 and 35 years. Three smokers were excluded from the analyses because their breath CO levels suggested they had not complied with the instructions to abstain on one occasion. A card-based, blocked, format was used for the modified Stroop task. Time to colour-name the words of the three motivational types, the order of which was counterbalanced across participants, was recorded. Smoking was associated with greater interference from both threat and appetitive words than from neutral words; during abstinence there was no differential effect of word type. Non-smokers performed more similarly to recent smokers. This pattern suggests suppression of normal motivational responding during abstinence.

Impaired dopamine-related motivation in nicotine addicts after overnight abstinence

Impaired dopamine-related motivation in nicotine addicts after overnight abstinence

Smoking, reward responsiveness, and response inhibition: tests of an incentive motivational model

Background: Incentive-motivation models of addiction suggest impairment of functional activity in mesocorticolimbic reward pathways during abstinence. This study tested implications for subjective and behavioral responses to nondrug incentives, cue-elicited craving, and prefrontal cognitive functions, particularly response inhibition. Methods: We tested 26 smokers after smoking and after overnight abstinence in counterbalanced order; 26 nonsmokers were also tested twice. Measures included a simple card-sorting test performed with and without financial incentive (the CARROT), the Snaith Hamilton Pleasure Scale as an index of subjective reward responsiveness, ratings of subjective craving and withdrawal before and after exposure to a cigarette, an index of oculomotor response inhibition (saccadic vs. antisaccadic eye movements), verbal fluency, and reversed digit span. Results: Compared with the smoking condition, and independently of withdrawal severity, abstinence was associated with reduced cue reactivity, pleasure expectancies, responsiveness to financial incentive, and response inhibition (antisaccadic eye movements). Verbal fluency and reversed digit span were unaffected, contrary to findings elsewhere with heavier smokers. Nonsmokers’ scores either fell between those of abstainers and recent smokers or approximated those of recent smokers. Conclusions: The data were in general consistent with behavioral predictions derived from the incentive-motivational model of addiction and suggest that abstinence may be associated with impairments of motivation and response inhibition, which are independent of other subjectively experienced withdrawal symptoms.

A Rapid Effect of Caffeinated Beverages on Two Choice Reaction Time Tasks

Though consumers of tea and coffee can report feeling beneficial subjective effects of consumption virtually immediately, tests for objective effects of caffeine immediately post-consumption have been rare. Two experiments examined caffeine's ability to influence reaction time in choice reaction time tasks, using a dose of caffeine typical of a cup of tea or instant coffee, and testing at short post-consumption delays. Two groups of participants were given 60 mg of caffeine, after overnight abstinence, either in a hot tea drink, or a hot water drink. Two control groups also received hot tea or water, but without caffeine. In Experiment 1, participants were given a keypress task before the drink (baseline), immediately after the drink, and 40 min after the drink. In Experiment 2, a touch-screen test was given either 1, 14, or 27 min post consumption. Caffeine was found to reduce the effect of a distracter on reaction time in the keypress test and to reduce reaction time in a component of the touch-screen task; however, in neither experiment were these effects significantly modulated by post-consumption delay length. Thus, the speed of caffeine's action on psychomotor performance was shown to be on the order of minutes.

Acute subjective and physiological responses to smoking in adolescents.

To determine the topography of cigarette smoking and the subjective and physiological effects of abstinence and nicotine in adolescents who smoke on a daily versus a non-daily basis. Repeated measures experiment, non-blinded, involving a single test session. Human psychopharmacology laboratory. Twenty-one daily and 21 non-daily adolescent cigarette smokers (21 females; 21 males; age 13-18 years) with life-time use greater than 10 cigarettes, responding to radio and print advertisements. Overnight abstinence from cigarettes followed by smoking of a single cigarette furnished by the participant at test. The Fagerstrom Test for Nicotine Dependence, saliva nicotine and cotinine, expired air carbon monoxide (CO), heart rate (HR), self-report scales and smoking topography. Most measurements were performed before and after smoking. Saliva nicotine, CO and HR increased, and self-reported intention and desire to smoke decreased, after smoking (p < 0.001). Fagerstrom scores indicated greater dependence and desire to smoke in daily than in non-daily smokers. HR increased substantially over pre-smoking levels in both groups. Puff topography did not differ between the groups, although collectively these participants appeared to take smaller and more puffs than adult smokers tested under similar conditions. This study provides initial evidence that adolescent cigarette smokers self-administer physiologically active doses of nicotine very early in their smoking careers. Nicotine dependence in adolescents appears to be a function of the current frequency of cigarette use, and subjective-behavioral consequences of abstinence and smoking are evident even in non-daily smokers.

Regional cerebral blood flow effects of nicotine in overnight abstinent smokers

Background: Most people agree that dependence to tobacco is mediated by the effects of nicotine on the central nervous system, albeit the neural pathways involved are not clearly delineated. We investigated the effect of nasal nicotine spray on regional cerebral blood flow (rCBF) in a sample of habitual smokers, with H 2 15O and positron emission tomography (PET). Methods: Eighteen volunteer smokers were studied after 12 hours of smoking deprivation. Regional cerebral blood flow measures were obtained with PET and 50 mCi H 2 15O in six consecutive scans. Nicotine spray and a placebo spray were administered in a single-blind design, preceded and followed by baseline studies. Images were coregistered and anatomically standardized. Square (9-mm side) regions of interest were placed in 10 preselected brain regions, bilaterally. The effects of the experimental condition and gender were tested with two-way repeated-measures analysis of variance in each of the regions studied. Results: Nicotine reduced rCBF in the left anterior temporal cortex and in the right amygdala. Increases were noted in the right anterior thalamus. Conclusions: In habitual smokers after overnight abstinence, nicotine induced differing effects on regional blood flow relative to whole brain blood flow. Increases were observed in the thalamus, a region rich in nicotinic receptors, and reductions in limbic and paralimbic (amygdala, anterior temporal cortex) regions.

Effects of a single dose of baclofen on self-reported subjective effects and tobacco smoking

Baclofen has been reported in uncontrolled clinical studies to reduce craving for abused drugs and reduce their rewarding effects. The objective of the present study was to measure the acute effects of a single dose of baclofen on cigarette smoking, craving for nicotine, cigarette taste, and smoking satisfaction. Tobacco smokers (n = 16) who were not trying to quit received baclofen (20 mg) or placebo after overnight abstinence during two laboratory sessions in a within-subjects design. We measured the subjective effects of baclofen on mood and self-reported ratings of craving for nicotine, and on the number of cigarettes smoked of the subjects' preferred brand during a 3-h ad libitum smoking period. Baclofen did not change the number of cigarettes smoked by the subjects nor did it change ratings of nicotine craving. However, baclofen altered the sensory properties of smoked cigarettes (e.g., increasing ratings of ‘harsh’ and decreasing ratings of ‘like cigarette's effects’). It also produced mild sedative-like subjective effects, such as increases in feeling ‘relaxed’. Thus, although baclofen did not reduce cigarette craving or smoking in the present study, it did produce some mood-altering effects and changes in sensory aspects of smoking that may facilitate smoking cessation.

A factor analysis of the Fagerstrom Tolerance Questionnaire

A factor analysis of 1309 Fagerstrom Tolerance Questionnaires (FTQ) was performed with liscomp software, which utilizes tetrachoric correlations to account for the dichotomous responses of the FTQ. Three factors with eigenvalues greater than 1.0 were obtained, accounting for 56.6% of the variance. Factor 1 was loaded by questions “How soon on waking do you smoke your first cigarette?,” “Do you find it difficult to refrain from smoking in places it is forbidden?,” “How many cigarettes a day do you smoke?,” and “Do you smoke if you are so ill that you are in bed most of the day?” Factor 2 was loaded by questions “Which cigarette would you hate to give up?” and “Do you smoke more during the morning than during the rest of the day?” Factor 3 was loaded exclusively by question “What brand do you smoke?” The question “Do you inhale always, sometimes, or never?” loaded exclusively on a fourth factor, however its eigenvalue did not reach significance. Support is provided for the modification of the eight-item FTQ to the six-item Fagerstrom Test for Nicotine Dependence (FTND). Based on the wording of the questions that loaded on each factor, we propose that Factor 2 assesses the degree of urgency to initiate smoking after overnight abstinence and that Factor 1 reflects the persistence of smoking during waking hours.

Acute effects of nicotine and mecamylamine on tobacco withdrawal symptoms, cigarette reward and ad lib smoking

Separate and combined effects of nicotine and the nicotinic antagonist mecamylamine were studied in 32 healthy volunteer smokers after overnight abstinence from smoking. Subjects participated in three sessions (3 h each), during which they wore skin patches delivering either 0 mg/24 h, 21 mg/24 h or 42 mg/24 h nicotine. Thirty-two subjects were randomly assigned to two groups receiving oral mecamylamine hydrochloride (10 mg) vs. placebo capsules. Two and one-half hours after drug administration, subjects were allowed to smoke ad lib, rating the cigarettes for rewarding and aversive effects. Transdermal nicotine produced a dose-related reduction in the subjective rewarding qualities of smoking. Nicotine also reduced craving for cigarettes and this effect was attenuated, but not eliminated, by mecamylamine. Mecamylamine blocked the discriminability of high vs. low nicotine puffs of smoke, and increased nicotine intake substantially during the ad lib smoking period. Some of the psychophysiological effects of each drug (elevation in blood pressure from nicotine, sedation and decreased blood pressure from mecamylamine) were offset by the other drug. The results supported the hypothesis that nicotine replacement can alleviate tobacco withdrawal symptoms even in the presence of an antagonist such as mecamylamine. Mecamylamine did not precipitate withdrawal beyond the level associated with overnight cigarette deprivation, suggesting its effects were primarily due to offsetting the action of concurrently administered nicotine as opposed to blocking endogenous cholinergic transmission.

Directed forgetting, event-related potentials and nicotine

Fifteen male users of oral snuff performed a directed forgetting task after over-night abstinence and after administration of oral snuff. Directed forgetting tasks use cues to classify items for differential reporting at test, emphasising the need for strategic encoding. Recognition was better after nicotine administration, but we found no evidence for greater strategic control, as hypothetically reflected in successful compliance with the directed forgetting instructions. Reaction time decreased after nicotine administration. Performance among fifteen controls was unaffected over two sessions.

Effects of nicotine in visual attention tasks

Thirty-five male volunteers (18 nicotine-users and 17 controls) participated in an experiment where a flanker task and a search task were used. It was hypothesized that if nicotine affects selective attention, the effects of distracting flanker stimuli should be diminished, and effects of allocation strategies in the search task should be more marked. Nicotine-users performed the tasks after an overnight abstinence, and after administration of oral snuff. In both tasks nicotine users improved more than controls, but there were no indications of nicotine effects on selective attention in either task. Our results point towards a non-specific arousing effect of nicotine.

Effects of nicotine in visual attention tasks

Thirty-five male volunteers (18 nicotine-users and 17 controls) participated in an experiment where a flanker task and a search task were used. It was hypothesized that if nicotine affects selective attention, the effects of distracting flanker stimuli should be diminished, and effects of allocation strategies in the search task should be more marked. Nicotine-users performed the tasks after an overnight abstinence, and after administration of oral snuff. In both tasks nicotine users improved more than controls, but there were no indications of nicotine effects on selective attention in either task. Our results point towards a non-specific arousing effect of nicotine.

Effects of nicotine abstinence and menstrual phase on task performance

Both menstrual phase and nicotine have been shown to affect task performance. Though conflicting results have been reported, at least one well-controlled study has demonstrated that women at midluteal phase show superior performance on speech articulation and speeded motor coordination tests, but poorer performance on perceptual-spatial tests, than during menses. Smokers have demonstrated superior performance on numerous tasks following nicotine than following placebo. To explore the separate and combined influence of these factors, we studied 13 regularly-menstruating smokers using a two (smoking vs. 12 hours' abstinence) by two (menstrual vs. midluteal phase) factorial design. During each session, subjects completed a test battery including two speeded motor coordination tasks, a computerized reaction time test, and the Stroop (1935) color/word test. Subjects completed the Stroop color and color-word tasks significantly faster after ad lib smoking than after overnight abstinence. No other significant differences emerged. Our findings replicate, in an all-female sample, previous reports that speed of cognitive processing is reduced by nicotine abstinence (or enhanced by nicotine administration). Our failure to observe menstrual cycle effects raises the possibility that the anti-estrogenic effects of smoking may attenuate phase differences in performance.

Tobacco abstinence, smoking cues, and the reinforcing value of smoking

One definition of the reinforcing value of a drug is the degree to which an organism will work to obtain it. Male and female smokers ( n = 8 each) engaged in a task involving concurrent schedules of reinforcement for responding to receive cigarette puffs versus money on four occasions, following overnight abstinence versus no abstinence and in the presense of a lit cigarette (smoking “cue”) or with no cigarette (2×2 design). Reinforcement schedule for puffs ranged from variable ratio 4 (VR4) to VR32, with schedule order during the first five trials (VR4 first, VR32 first) counterbalanced and repeated in reverse sequence during the second five trials. Schedule for money remained at VR4 during all trials. Results indicated significantly greater responding for puffs after overnight abstinence and in the presence of the smoking cue, although effect of the cue was specific to the “leaner” VR schedules (VR16, VR32). Unexpectedly, not only was reinforcement schedule for puffs a significant determinant of responding, but the order of these schedules (i.e. VR4 first vs. VR32 first) produced a significant overall difference in responding for puffs, especially in the presence of the cue. There was no difference in responding between males and females. These findings indicate that the reinforcing value of smoking is increased by overnight abstinence, the presence of a lit cigarette under lean reinforcement conditions, and the order in which reinforcement schedules are presented.

Increased dependence on blood glucose in smokers during rest and sustained exercise.

To evaluate the hypothesis that smoking increases the dependence on blood glucose as a fuel, seven male smokers [28.7 +/- 1.7 (SE) yr. 77.7 +/- 4.3 kg] and seven nonsmokers (NS; 29.1 +/- 0.9 yr, 78.7 +/- 5.3 kg) were studied in the postabsorptive condition. NS received a primed continuous infusion of [6,6-2H]glucose and [1-13C]glucose during 90 min of rest and 60 min of exercise at 49.7 +/- 0.8% of peak O2 consumption on one occasion; chronic smokers continued their overnight abstinence from smoking (CS) for one trial but, on another occasion, acutely smoked (AS) two cigarettes immediately before resting measurements and another cigarette before exercise. Plasma glucose levels were similar among all groups at all times during the trials; however, the glucose rates of appearance (Ra) at rest in CS (1.96 +/- 0.14 mg.kg-1 x min-1) and AS (2.02 +/- 0.14) were higher than in NS (1.41 +/- 0.15, P < 0.05). With exercise, the glucose Ra values rose in all groups above resting values but were significantly greater in CS (4.76 +/- 0.50) and AS (4.71 +/- 0.53) than in NS (3.31 +/- 0.16). Glucose oxidation during exercise was elevated in smokers (2.31 +/- 0.37 mg.kg-1 x min-1 in CS and 2.18 +/- 0.34 in AS) compared with NS (1.09 +/- 0.18, P < 0.05). Nicotine levels correlated with the glucose Ra in AS (r = 0.93, P < 0.01). In conclusion, the results indicate that long-term smoking, independent of acute smoking, increases the dependence on blood glucose as a fuel during rest and sustained submaximal exercise.

Nicotine intake and dependence in Swedish snuff takers.

Two studies examining nicotine intake in users of Swedish moist oral snuff are reported. Absorption form a single pinch (2 g) in ten users after overnight abstinence was fairly rapid. The increment in plasma nicotine concentrations averaged 9.9 ng/ml (SD 6.5) after 10 min and peaked at 14.5 ng/ml (SD 4.6) shortly after discarding at 30 min. Among groups of habitual snuff takers (n = 27) and cigarette smokers (n = 35) studied on a day of normal snuffing/smoking, peak blood nicotine levels after use were similar [averaging 36.6 ng/ml (SD 14.4) and 36.7 ng/ml (SD 16.1), respectively], but there was a tendency to higher cotinine levels in the snuffers (399.2 ng/ml versus 306.3 ng/ml). The snuff takers and cigarette smokers reported similar levels of subjective dependence on tobacco. Epidemiological study of Swedish snuff users could clarify whether the cardiovascular risks of tobacco are attributable to nicotine or to other smoke components, as in their case nicotine intake is not accompanied by combustion products.

Short- and long-term effects of cigarette smoking on heart rate variability

The short- and long-term effects of cigarette smoking on autonomic cardiac regulation were investigated by power spectral analysis of heart rate variability under controlled respiration (15/ min). The short-term effects were examined in 9 smokers without evidence of cardiopulmonary disorders after an overnight abstinence from smoking. The heart rate spectral component reflecting the respiratory sinus arrhythmia (0.25 Hz), a quantitative index of vagal cardiac control, decreased 3 minutes after smoking 1 cigarette (p = 0.0061) and the component reflecting Mayer wave sinus arrhythmia (0.04 to 0.15 Hz), which includes sympathetically mediated activity, increased after 10 to 17 minutes (p = 0.0124). The long-term effects were examined in 81 normal subjects comprising 25 nonsmokers, 31 moderate (1 to 24 cigarettes/ day) smokers and 25 heavy (>25 cigarettes/day) smokers after an overnight abstinence. Although the magnitude of the Mayer wave component was unaffected by the smoking status, the respiratory component in the supine position was smaller in the young (≤30 years) heavy smokers than in the young nonsmokers or moderate smokers (p = 0.0078). Also, postural changes in the components, a decrease in the respiratory component and an increase in the Mayer wave component with standing, were observed in the nonsmokers but not in the heavy smokers. These results suggest that smoking causes an acute and transient decrease in vagal cardiac control, and that heavy smoking causes long-term reduction in vagal cardiac control in young people and blunted postural responses in autonomic cardiac regulation.