A pilot study on voucher-based incentives to promote abstinence from cigarette smoking during pregnancy and postpartum.

We report results from a pilot study examining the use of vouchers redeemable for retail items as incentives for smoking cessation during pregnancy and postpartum. Of 100 study-eligible women who were still smoking upon entering prenatal care, 58 were recruited from university-based and community obstetric practices to participate in a smoking cessation study. Participants were assigned to either contingent or noncontingent voucher conditions. Vouchers were available during pregnancy and for 12 weeks postpartum. In the contingent condition, vouchers were earned for biochemically verified smoking abstinence. In the noncontingent condition, vouchers were earned independent of smoking status. Abstinence monitoring and associated voucher delivery was conducted daily during the initial 5 days of the cessation effort, gradually decreased to every other week antepartum, increased to once weekly during the initial 4 weeks postpartum, and then decreased again to every other week for the remaining 8 weeks of the postpartum intervention period. Contingent vouchers increased 7-day point-prevalence abstinence at the end-of-pregnancy (37% vs. 9%) and 12-week postpartum (33% vs. 0%) assessments. That effect was sustained through the 24-week postpartum assessment (27% vs. 0%), which was 12 weeks after discontinuation of the voucher program. Total mean voucher earnings across antepartum and postpartum were 397 US dollars (SD=414 US dollars) and 313 US dollars (SD=142 dollars) in the contingent and noncontingent conditions, respectively. The magnitude of these treatment effects exceed levels typically observed with pregnant and recently postpartum smokers, and the maintenance of effects through 24 weeks postpartum extends the duration beyond those reported previously.     

Belief about drug assignment and abstinence in treatment of cigarette smoking using nortriptyline.

This study assessed the relationship between beliefs about drug assignment and abstinence status in two treatment studies using nortriptyline hydrochloride as an adjunct to smoking cessation. Smokers (N = 345) drawn from two clinical trials were asked at the final follow-up (FFU) at 52 or 64 weeks whether they believed they had received active or placebo drug. Responses were obtained from 262 participants, or 76% of the sample. Biochemically verified abstinence was collected at end of treatment (EOT) and FFU. In both studies, participants were correct in guessing drug assignment. At FFU, belief about drug assignment was not related to abstinence for either active or placebo participants. Participants who received active drug and who were smoking at EOT were more likely to believe they had received placebo than active drug participants who were abstinent at EOT. We found no significant relationship between belief about drug and abstinence status for placebo participants at EOT. Baseline variables did not significantly predict correctness of drug identification. Participants who experienced drug side-effects not easily attributable to nicotine withdrawal were more likely to identify their drug assignment as nortriptyline. We conclude that experience during the active treatment period, including side-effects and treatment success, may be related to belief about drug assignment, that the field would be well served by at least two assessments of blindness in clinical trials, and that discrepancy between these findings and those regarding nicotine replacement therapy may be related to differences in dependent variables.     

Cough following initiation of smoking abstinence.

Some clinicians and patients believe that cough and sputum production may transiently increase over the first weeks after smoking cessation and may in fact represent a barrier to successful quitting. The present study described changes in cough after an attempt to quit smoking cigarettes and determined patients' perceptions of how changes in cough affected their ability to maintain abstinence from smoking. Daily smokers already recruited for ongoing outpatient clinical trials of pharmacological aids to quit cigarette smoking were invited to complete self-report questionnaires about their cough for up to 6 weeks after their target quit date (TQD). Of the 176 subjects invited to participate, 112 completed the first assessment after the TQD. Of these, a total of 45 subjects maintained at least 1week of smoking abstinence at some point in the 6-week period (confirmed by carbon monoxide measurements). Two self-report measures found that cough declined steadily in abstinent smokers but was constant in a comparator group of continuing smokers (n = 36). For the 94 subjects who reported smoking at least one cigarette following the TQD, few reported that changes in cough affected their abstinence attempt. For three items asking about this area, the upper 95% confidence interval was no more than 10% for agreement that changes in cough posed any barrier to abstinence. We conclude that an initial increase in cough is unlikely to occur among relatively healthy smokers who stop smoking and that changes in cough do not represent a barrier to maintaining abstinence for most smokers.     

Effects of smoking abstinence and alcohol consumption on smoking-related outcome expectancies in heavy smokers and tobacco chippers.

Smoking cessation interventions often target expectancies about the consequences of smoking. Yet little is known about the way smoking-related expectancies vary across different contexts. Two internal contexts that are often linked with smoking relapse are states associated with smoking abstinence and alcohol consumption. This report presents a secondary analysis of data from two experiments designed to examine the influence of smoking abstinence, and smoking abstinence combined with alcohol consumption, on smoking-related outcome expectancies among heavy smokers and tobacco chippers (smokers who had consistently smoked no more than 5 cigarettes/day for at least 2 years). Across both experiments, smoking abstinence and alcohol consumption increased expectancies of positive reinforcement from smoking. In addition, alcohol consumption increased negative reinforcement expectancies among tobacco chippers, such that the expectancies became more similar to those of heavy smokers as tobacco chippers' level of subjective alcohol intoxication increased. Findings suggest that these altered states influence the way smokers evaluate the consequences of smoking, and provide insight into the link between smoking abstinence, alcohol consumption, and smoking behavior.     

Long-term changes in sleep and depressive symptoms of smokers in abstinence.

Few studies have evaluated the impact of smoking cessation on objective measures of sleep. The present study assessed the long-term effects of tobacco smoking abstinence on sleep and depression. A total of 15 chronic smokers with Hamilton Rating Scale for Depression (HAM-D) scores of less than 9 were evaluated. Subjects were screened for baseline data when they were smoking chronically. They underwent a 5-week psychological treatment for tobacco smoking, after which their depressive symptoms and sleep architecture were evaluated at 1, 2, 4, 6, 9, and 12 months of abstinence. We report the results of the seven patients who completed 1 year of evaluations and of those patients who achieved only partial abstinence. Polysomnographic recordings were taken, level of depression was measured with the HAM-D, and urinary cotinine levels also were evaluated. HAM-D scores were analyzed with and without sleep items. Nicotine abstinence reduced latency to rapid eye movement (REM) sleep and increased HAM-D scores, suggesting that chronic smokers have depressive symptoms that may be controlled by nicotine administration.     

Urine cotinine as an index of smoking status in smokers during 96-hr abstinence: comparison between gas chromatography/mass spectrometry and immunoassay test strips.

Biomarkers such as carbon monoxide (CO) and cotinine (a nicotine metabolite) are used in tobacco cessation studies to assess smoking status. CO is easy to assess, is inexpensive, and provides immediate results. However, the short half-life of CO may limit its ability to identify smokers who have abstained for several hours. Quantitative methods (e.g., gas chromatography/mass spectrometry, or GC/MS) for measuring urine cotinine, which has a longer half-life, are valid and reliable, though costly and time consuming. Recently developed semiquantitative urine cotinine measurement techniques (i.e., urine immunoassay test strips, or ITS) address these disadvantages, though the value of ITS as a means of identifying abstaining smokers has not been evaluated. The present study examined ITS as a measure of smoking status in temporarily abstaining smokers. A total of 236 breath and urine samples were collected from smokers who participated in two separate studies involving three independent, 96-hr (i.e., Monday-Friday), Latin-square-ordered, abstinence or smoking conditions; a minimum 72-hr washout separated each condition. Each urine sample was analyzed with GC/MS and ITS. Under these study conditions, CO demonstrated moderate sensitivity (83.1%) and strong specificity (100%), whereas ITS assessment showed strong sensitivity (98.5%) and weak specificity (58.5%). In this study of short-term abstinence, ITS classified as nonabstinent nearly half of the samples collected from abstaining smokers. However, it classified nearly all nonabstinent smokers as currently smoking. Validation of ITS using GC/MS results from smokers undergoing more than 96 hr of abstinence may be valuable.     

Predictors of smoking cessation among elderly smokers treated for nicotine dependence

OBJECTIVE: To examine outcomes and predictors of smoking cessation among elderly patients treated for nicotine dependence. DESIGN: Retrospective analysis of patients aged 65-82 who received a nicotine dependence consultation at the Mayo Medical Center between 1 April 1988 and 30 May 1992. Patients were contacted by telephone by a trained interviewer six months after the consultation and were sent a follow-up survey in August 1993. SETTING: Mayo Medical Center, Rochester, Minnesota, United States. SUBJECTS: A total of 613 patients (310 men, 303 women) with a mean age of 69.0 (SD 3.5) years were seen during the study period. MAIN OUTCOME MEASURES: Point prevalence self-reported smoking status. Patients were considered abstinent if they self- reported not smoking (not even a puff) during the seven days before contact. RESULTS: At six-month follow up, 24.8% of the 613 patients reported abstinence from smoking. On multivariate analysis, smoking abstinence was more likely if patients were hospitalised at the time of the consultation, married to a non-smoking spouse, very motivated to stop smoking, and reported their longest time of previous abstinence to be less than a day or more than a month. The response rate to the mailed follow-up survey was 69.9% (429 of 613). The mean duration of follow up was 40.0 +/- 13.2 months following the consultation. Of the 429 patients, 103 (24.0%) reported abstinence from smoking and 326 (76.0%) were smoking at six-month follow up. Patients who reported abstinence at six months had a higher cessation rate at the last follow up (76.0%) compared with patients who were smoking at six-month follow up (33.0%, P < 0.001). For patients who were not smoking at six months, no factors were found to significantly predict abstinence at last follow up. For patients who were smoking at six months, factors associated with smoking cessation at last follow up were: more than a year as the longest time off cigarettes before the consultation; counsellor rating of less severe nicotine dependence; and older age at first regular smoking. CONCLUSIONS: Several predictors of smoking cessation were identified in this study which may be useful for tailoring smoking interventions for the elderly.


     

Comparison of the effects of a 24-hour nicotine patch and a 16-hour nicotine patch on smoking urges and sleep.

This randomized, open-label, crossover study was conducted to compare the effects of a 24-hr nicotine patch and a 16-hr nicotine patch on morning smoking urges and sleep quality of dependent smokers during a short period of cigarette abstinence. A total of 20 smokers (9 women and 11 men) smoking at least 20 cigarettes/day completed the two smoke-free study periods. For each period, cigarette abstinence started on the first evening and a nicotine patch was applied the next morning (for 16 or 24 hr), after baseline measures; a second patch was applied the next morning, 1 hr before the end of the experimental period. Smoking urges, mood and behavior self-reports, psychomotor performance, and polysomnographic recordings were compared between the two types of nicotine patch according to changes from baseline. Both patches decreased morning smoking urges, although results were significantly superior for the 24-hr patch. Furthermore, the 24-hr patch was more effective than the 16-hr patch in reducing the positive reinforcing dimension of smoking urges. Regarding polysomnographic recordings, the proportion of slow wave sleep was significantly increased from baseline with the 24-hr patch compared with the 16-hr patch. As for psychomotor performance measured through the critical flicker fusion test, significant improvement in morning alertness was observed in the 24-hr patch group. In conclusion, the 24-hr nicotine patch formulation is more effective than the 16-hr formulation in alleviating morning smoking urges and more specifically the positive reinforcing factor. The present findings do not support the idea that nicotine delivery during bedtime might disturb sleep, but rather it improves restorative sleep and postwaking arousal.     

Is concern about post-cessation weight gain a barrier to smoking cessation among pregnant women?

Women who quit smoking during pregnancy gain more weight than women who continue to smoke. Concern about weight gain is a barrier to smoking cessation in the general population, but whether attitudes about weight are associated with failure to stop smoking during pregnancy or to maintain abstinence postpartum is unknown. Thus, attitudes about weight were assessed in 412 pregnant smokers recruited from obstetric practices in Massachusetts for a smoking cessation intervention trial. Smoking cessation outcomes (7-day point-prevalence abstinence by self-report and by cotinine-validation) were assessed at end-of-pregnancy and 3 months postpartum. Bivariate and multivariable analyses assessed the relationship between attitudes about weight and smoking cessation. In bivariate analyses, a high level of concern about post-cessation weight gain was associated with older age (p = .01), smoking more cigarettes/day (p<.001), not making a quit attempt in pregnancy (p = .02), being less likely to self-report tobacco abstinence at end of pregnancy (p = .01) and postpartum (p = .02), and having less cotinine-validated abstinence at 3 months postpartum (p = .05). In multivariable analyses that adjusted for cigarettes/day, a low level of concern about post-cessation weight gain was associated with more self-reported abstinence at end-of-pregnancy (OR = 1.77, 95% CI 1.01-3.09) and postpartum (OR = 2.09, 95% CI 1.05-4.14), but not with cotinine-validated abstinence at end-of-pregnancy (OR = 1.30, 95% CI 0.63-2.68) or postpartum (OR = 2.18, 95% CI 0.93-5.10). In conclusion, women who are more concerned about post-cessation weight gain may be less likely to quit smoking during pregnancy or remain abstinent in the postpartum period.     

Effects of smoking abstinence, smoking cues and nicotine replacement in smokers with schizophrenia and controls.

The mechanisms underlying the low smoking cessation rates among smokers with schizophrenia (SS) are unknown. In this laboratory study, we compared the responses of 21 SS and 21 non-psychiatric controls (CS) to manipulations of 5-hour smoking abstinence, transdermal nicotine replacement (0 mg, 21 mg and 42 mg), and in vivo smoking cues. Results indicate that SS were more sensitive than CS to the effects of acute abstinence on carbon monoxide (CO) boost, but not more sensitive to the effects of abstinence on urge levels or withdrawal symptoms. SS and CS did not differ in urge response to in vivo smoking cues, but SS were less consistent in their reactions. These findings suggest that heightened sensitivity to the effects of abstinence on smoke intake may partially account for the low cessation rates experienced by SS, but other potential mechanisms should be explored using behavioral laboratory models.     

The role of impulsivity on smoking maintenance.

In order to better understand why those higher in impulsivity experience more difficulties during smoking abstinence, the current study examined the possible mechanisms contributing to cigarette smoking relapse. Fifty dependent cigarette smokers completed measures designed to assess craving, tobacco withdrawal severity, and negative affect during 48 hours of nicotine abstinence. Using a series of multilevel models (SAS Proc Mixed Procedure), significant impulsivity x time analyses revealed differences in craving, F(2, 96) = 3.74, p<.05, and anxiety, F(2, 96) = 3.23, p<.05. Simple slopes analyses indicated that heightened trait-impulsivity predicted greater increases in craving and anxiety during a 48-hour abstinence period. These findings suggest that smokers with higher levels of impulsivity may lack the ability to find an accessible and comparable substitute for cigarette smoking during a cessation attempt. This study also highlights the importance of considering individual differences when treating those who wish to quit smoking.     

Interventions to increase use of nicotine gum: a randomized, controlled, single-blind trial.

Medication noncompliance with smoking cessation pharmacotherapies is a significant problem in both research and clinical settings. This randomized, controlled, single-blind study compared three single-session psychological interventions to increase use of nicotine gum during a 15-day treatment period. A total of 97 adult smokers were randomized to receive standard treatment (ST, n = 31), brief feedback (BF, n = 32) plus ST, or contingency management (CM; i.e., payment for chewing at least 12 pieces/day on 10 of 15 intervention days, n = 34) plus ST and BF. Only the CM condition led to significantly greater average daily gum use (pieces/day: ST, 6.17; BF, 7.81; CM, 10.17 [p values <.05]) and higher rates of compliance (ST, 13.6%; BF, 25.2%; CM, 65.6% [p values <.001]). No differences were observed in smoking abstinence, nicotine withdrawal, or urinary cotinine as a function of treatment. Implications of the present findings are discussed, including application to clinical trials and extension to real-world use of nicotine gum.     

The effectiveness of smoking cessation interventions prior to surgery: a systematic review.

The objective of this review was to evaluate the effectiveness of smoking cessation interventions prior to surgery and examine smoking cessation rates at 6 months follow-up. The Cochrane Library Database, PsycINFO, EMBASE, Medline, and Cinahl databases were searched using the terms: smok$, smoking cessation, tobacco, cigar$, preop$, operati$, surg$, randomi*ed control$ trial, intervention, program$, cessation, abstinen$, quit. Further articles were obtained from reference lists. The search was limited to articles on adults, written in English and published up to December 2006. Only randomized control trials (RCTs) that incorporated smoking cessation interventions to patients awaiting elective surgery were included. Seven studies met the inclusion criteria. Methodological quality was assessed by all the authors. The findings revealed that short-term quit rates (or a reduction by more than half of normal daily rate) ranged from 18% to 93% in patients receiving a smoking intervention (mean 55%), compared with a range of 2%-65% of controls (mean = 27.7%). Two studies examined smoking status at 6 months but these revealed no significant difference in abstinence rates between patients who had received an intervention and those that had not. Studies that incorporated counseling in addition to nicotine replacement therapy appeared to show greater benefits. It is concluded that smoking cessation interventions prior to surgery are effective in helping patients to quit smoking. However, such effects appear to be short-lived. Future research needs to examine intervention and patient factors to see whether tailoring the smoking cessation intervention specifically to the patient improves overall abstinence rates.     

Association of post-treatment smoking change with future smoking and cessation efforts among adolescents with psychiatric comorbidity.

Little is known about how initial change following a smoking intervention relates to longer-term smoking outcomes among adolescent smokers with psychiatric comorbidity. The present study investigated this relationship among psychiatrically hospitalized adolescents (N = 183) who participated in a controlled trial comparing motivational interviewing to brief advice. Quit attempters (n = 37), reducers (n = 45), and maintainers (n = 101) were assembled based on, respectively, having made a quit attempt, having reduced smoking by at least 50%, and having reduced smoking by less than 50% in the first week after hospital discharge. Hierarchical linear models and generalized estimating equations were conducted to test group differences in average number of cigarettes per smoking day and odds of making a quit attempt during subsequent weeks of a 12-month continuous follow-up, and in cotinine-verified abstinence rates at 1, 6, and 12 months posthospitalization. Baseline smoking levels and presence of a substance use disorder or anxiety disorder were predictive of outcomes. After controlling for covariates, we found that quit attempters smoked less during follow-up than did the other change groups and that reducers smoked less than maintainers. Quit attempters evidenced a higher percentage of quit attempts during follow-up than did the other change groups. Reducers had a greater average percentage of quit attempts during follow-up than did maintainers. However, groups did not differ on cotinine-verified abstinence rates across the follow-up period. Findings have implications for initial post-treatment change as it relates to subsequent smoking and cessation outcomes among adolescent smokers at especially high risk for smoking persistence.     

Social support as a moderator of the relationship between recent history of depression and smoking cessation among lower-educated women.

We examined psychosocial mechanisms linking recent history of depression and subsequent short-term smoking cessation. Our sample included lower-educated women smokers who registered for a brief cessation intervention (registrant panel; n = 1,198), and a quasicontrol panel not participating in the intervention (population panel; n = 682). Women were surveyed by telephone every 6 months for a period of 2 years, measuring psychosocial variables (motivation, self-efficacy, perceived stress, and social support) and self-reported smoking status (7-day abstinence) at each point. In both panels, smoking rate and self-efficacy were strong independent predictors of subsequent cessation, but recent history of depression (as measured 6 months earlier) was not a significant predictor. However, among only the registrant panel, the effects of recent history of depression were significantly moderated by social support. Recently depressed women who had higher levels of perceived social support were as likely to quit subsequently as women who did not have a recent history of depression. The determinants of successful quitting among lower-educated women differ between those who seek assistance and those who do not.     

Subjective and physiological responses to smoking cues in smokers with schizophrenia.

The prevalence of smoking is high among people with schizophrenia. Although several research groups are developing smoking treatments for these smokers, abstinence rates to date have been modest. Methodological tools such as cue exposure are useful in clinical research with smokers in general, but the value of these paradigms with smokers with schizophrenia has yet to be established. The aim of the present study was to determine the subjective and physiological effects of exposure to in vivo smoking cues in smokers with schizophrenia. A total of 25 heavy smokers with schizophrenia or schizoaffective disorder were assessed while nonabstinent and after 2-hr smoking abstinence. Urge to smoke, mood, nicotine withdrawal symptoms, heart rate, and blood pressure were measured during a precue relaxation period, after exposure to neutral cues, and after exposure to smoking cues. Results indicate that both exposure to smoking cues and brief abstinence increased urge levels, nicotine withdrawal symptom levels, and negative affect. Abstinence did not amplify the effects of cues on urges or other cue reactivity measures. These results indicate that smoking cue reactivity laboratory models may be useful for investigating potential smoking treatments for, or neurobiological contributions to, smoking behavior in smokers with schizophrenia.     

Errors in interpreting abstinence curves in studies of smoking cessation.

Articles on smoking cessation often present curves representing the percentage of smokers still abstinent over time. The purpose of this paper is to illustrate how common conclusions from inspecting these curves may be misleading because they are based on assumptions of which readers are not aware. For example, when active and control abstinence curves converge, this is often interpreted to indicate a diminution of treatment effect size over time. We use illustrative data to show that this interpretation is correct if one assumes a treatment has a constant additive effect; however, if one assumes treatment has a constant multiplicative effect, then converging curves can still indicate a constant treatment effect. Converging abstinence curves are also often interpreted to indicate that the rate of relapse is greater in the active than the control group. We illustrate that this interpretation is correct if one is interested in cumulative relapse rate and uses all subjects in the denominator; however, if one is interested in relapse over a discrete subperiod of time (e.g., immediately after treatment stops), and thus uses only those at risk for relapse, then converging curves can still indicate a constant relapse rate. When trials interpret abstinence curves, they should make clear whether they are assuming additive or multiplicative effects of treatment and are discussing overall or local relapse rates. They should also report both additive and multiplicative effect sizes.     

Smoking cessation in homeless populations: a pilot clinical trial.

This study, which tested two motivational interviewing treatment approaches, assessed the feasibility of conducting a community-based smoking cessation intervention among homeless smokers. Participants (N = 46) were recruited from multiple facilities in the Kansas City area and were randomized to two counseling conditions in which they received five individual motivational interviewing sessions, six group meetings, and their choice of 8 weeks of 21-mg nicotine patch or 4-mg nicotine lozenge. The two counseling conditions consisted of motivational interviewing targeted either to smoking behaviors exclusively (smoking only) or to smoking and other addictions or life events that could affect ability to quit (smoking plus). Group meetings were designed to provide educational information and social support. Measures of feasibility assessed included the proportion of participants who returned for randomization among those eligible, adherence to prescribed nicotine replacement therapies, retention rates at the week 26 final study visit, and biochemically verified 7-day abstinence at week 26. Most participants (69.6%) chose nicotine patches, and 32% of those participants reported using at least four patches per week. Carbon monoxide verified 7-day abstinence rates in the smoking-only and smoking-plus groups were 13.04% and 17.39% (ns), respectively, at week 8 and 8.70% and 17.39% (ns), respectively, at week 26. Participants who used at least four patches per week were more likely to have quit at 8 weeks than were those who used fewer patches (33.3% vs. 10.5%, p = .30). Results support the feasibility of conducting a smoking cessation intervention among homeless smokers. Findings also show promising effects for nicotine replacement therapy and counseling in this population. Developing programs to improve smoking cessation outcomes in underserved populations is an essential step toward achieving national health objectives and for ultimately reducing tobacco-related health disparities.     

Tobacco craving predicts lapse to smoking among adolescent smokers in cessation treatment.

Previous research indicates that tobacco craving predicts relapse to smoking among adult smokers attempting to quit. We hypothesized a similar relationship between craving and lapse (any smoking following a period of abstinence) among adolescent smokers during the treatment phase of a clinical trial. A visit was considered a lapse visit if the participant reported smoking or had a carbon monoxide level of 7 ppm or greater subsequent to an abstinent visit. A total of 34 participants (mean age = 14.9 years [SD = 1.3]; mean cigarettes/day = 18.0 [SD = 7.6]; mean Fagerstr?m Test for Nicotine Dependence score = 6.8 [SD = 1.34]; 65% female), were included in the present analysis of 167 treatment visits. Logistic regression analyses showed a positive relationship between degree of craving, measured by the Questionnaire on Smoking Urges, and lapse during smoking cessation treatment (p = .013). Additionally, linear regression analyses demonstrated a strong positive association between cigarettes smoked per day and craving scores (p<.001). Taken together with other data, these findings suggest that degree of craving might influence tobacco abstinence for adolescent smokers. Thus monitoring and addressing craving appears useful to increase the success of adolescent smoking cessation.     

Effects of abstinence from tobacco: valid symptoms and time course.

This article updates a 1990 review of the effects of tobacco abstinence by reviewing (a) which symptoms are valid indicators of tobacco abstinence and (b) the time course of tobacco abstinence symptoms. The author searched several databases to locate more than 3,500 citations on tobacco abstinence effects between 1990 and 2004; 120 of these were used in this review. Data collection and interpretation were based solely on the author's subjective judgments. For brevity, the review does not evaluate craving, hunger, performance, and several other possible outcomes as withdrawal symptoms. Anger, anxiety, depression, difficulty concentrating, impatience, insomnia, and restlessness are valid withdrawal symptoms that peak within the first week and last 2-4 weeks. Constipation, cough, dizziness, increased dreaming, and mouth ulcers may be abstinence effects. Drowsiness, fatigue, and several physical symptoms are not abstinence effects. In conclusion, no major changes are suggested for DSM-IV criteria for tobacco/nicotine withdrawal, but some deletions are suggested for ICD-10 criteria. Future studies need to investigate several possible new symptoms of withdrawal and to define more clearly the time course of symptoms.