Association between monoamine oxidase gene polymorphisms and smoking behaviour in Chinese males

Monoamine oxidase (MAO) is a critical metabolic enzyme of dopamine, which is a key neurotransmitter of the mesolimbic reward pathway in the human brain. Consequently, the gene encoding MAO is an important candidate gene in the genetics of smoking behaviour. We investigated the association between MAOA polymorphisms (a VNTR polymorphism and an EcoRV polymorphism) and smoking status. A community-based cross-sectional study was conducted with 203 current smoking subjects and 168 non-current smoking subjects in Beijing, China. Genotyping for these polymorphisms was performed using PCR and restriction fragment length polymorphism. Multiple logistic regression models were used to analyse the association of MAOA gene polymorphisms with smoking status. We found that individuals with the 1460T/O genotype had a significantly increased the risk of smoking compared to those with 1460C/O. The adjusted odds ratios (aORs) were 3.2 (95% CI 2.0-5.2) in current vs. non-current smokers group, 1.7 (95% CI 1.1-2.8) in ever vs. never smokers group, 2.5 (95% CI 1.4-4.3) in current vs. never smokers group, and 5.3 (95% CI 2.5-11.2) in current vs. former smokers group respectively. We also found that individuals with the 3-repeat genotype of the VNTR polymorphism had a significantly increased risk of smoking significantly compared to those with the 4-repeat genotype. The aORs were 2.0 (95% CI 1.0-4.1) in the current vs. former smokers group, and 1.9 (95% CI 1.0-3.6) in the nicotine dependent vs. non-nicotine dependent group respectively. Moreover, MAOA gene haplotypes were associated significantly with nicotine dependence in every group. In conclusion, there is an important association between MAOA polymorphisms and smoking status, suggesting a possible role of MAOA gene variants in nicotine dependence.     

Association between polymorphisms in dopamine metabolic enzymes and tobacco consumption in smokers

Central dopaminergic reward pathways give rise to dependence and are activated by nicotine. Allelic variants in genes involved in dopamine metabolism may therefore influence the amount of tobacco consumed by smokers. We developed assays for polymorphisms in dopamine beta-hydroxylase (DBH), monoamine oxidase (MAO) and catechol O-methyl transferase (COMT) using the polymerase chain reaction with sequence specific primers (PCR-SSP). We then typed 225 cigarette smokers to assess whether genotype was related to the number of cigarettes smoked a day. Smokers with DBH 1368 GG genotype smoked fewer cigarettes than those with GA/AA [mean difference -2.9 cigarettes, 95% confidence interval (CI) -5.5, -0.4; P = 0.022]. The effect reached statistical significance in women (-3.8, 95% CI -6.4, -1.0, P = 0.007) but not in men (-1.5, 95% CI -6.0, 3.0, P = 0.498). Overall, the effect was greater when analysis was confined to Caucasians (-3.8, 95% CI -6.6, -1.1, P = 0.007). Smokers with MAO-A 1460 TT/TO smoked more cigarettes than those with CC/CT/CO (2.9, 95% CI 0.6, 5.1, P = 0.013). Within each sex group, the trend was similar but not statistically significant (difference for men 2.9, 95% CI -1.0, 6.7; for women 2.0, 95% CI -0.7, 4.8). The effect of the allele was greater in smokers with a high body mass index (> 26) (difference 5.1, 95% CI 1.4, 8.8, P = 0.008). More heavy smokers (> 20 a day) had the DBH 1368A allele when compared to light smokers (< 10 a day). (Relative risk 2.3, 95% CI 1.1, 5.0, P = 0.024.) The trend for increasing prevalence of the DBH A allele in heavy smokers was greater when analysis was restricted to Caucasians (relative risk 3.2, 95% CI 1.3, 8.2, P = 0.004). Conversely, heavy smokers were less likely to have the MAO-A 1460C allele (relative risk 0.3, 95% CI 0.1, 0.7, P = 0.012). Variations in DBH and MAO predict whether a person is a heavy smoker and how many cigarettes they consume. Our results support the view that these enzymes help to determine a smoker's requirement for nicotine and may explain why some people are predisposed to tobacco addiction and why some find it very difficult to stop smoking. This finding has important implications for smoking prevention and offers potential for developing patient-specific therapy for smoking cessation.     

The Fagerstrom Test for Nicotine Dependence and the Diagnostic Interview Schedule: do they diagnose the same smokers?

Two common assessment tools for nicotine dependence are the Fagerstrom Test for Nicotine Dependence (FTND) and the Nicotine Dependence section of the Diagnostic Interview Schedule [(DIS)-III-R or -IV based on the Diagnostic and Statistical Manual (DSM)-III-R and -IV, respectively]. The FTND emphasizes morning smoking and overall "heaviness" of smoking. The DSM emphasizes adverse consequences, desire to cut down, and mood changes during withdrawal. We tested (1) how the DSM-III-R diagnosis of Nicotine Dependence is related to FTND score; and (2) how the (a) DSM-III-R or (b) elevated FTND score is related to longer smoking histories, greater psychiatric symptomatology, and tobacco liking scores. Retrospective chart reviews were conducted on 370 smokers, the majority (55.9%) of whom had a current DSM-III-R diagnosis of Substance Dependence other than nicotine. All subjects had completed the FTND, the DIS-III-R, the Symptom Checklist-90-Revised (SCL-90-R), and a survey on drug liking. Agreement statistics were calculated between the DSM-II-R diagnosis of Nicotine Dependence and various cutoff scores values that were assigned as thresholds for nicotine dependence on the FTND. At no cutoff score did the two instruments reliably agree; the highest kappa (at a cutoff of FTND > or = 7) was 0.205. At cutoffs above 5, the FTND diagnosed fewer cases than the DSM-III-R. Multiple regression analysis showed that DSM diagnosis was associated with greater psychiatric symptomatology on the SCL-90-R, while FTND scores were associated with greater tobacco liking. The FTND and the DSM-III-R appear to measure different aspects of the tobacco dependence process. Specifically, the FTND may provide a stronger measure of physical dependence, while the DSM may tap other domains such as awareness of dependence, behaviors resulting from that awareness, and psychiatric symptomatology. Disagreements between the FTND and the DSM are likely to become greater with the changes in the DSM-IV.     

Cognitive interviews for measurement evaluation of the Fagerström Test for Nicotine Dependence (FTND) in smokers with schizophrenia spectrum disorders

People diagnosed with schizophrenia have among the highest known rates of tobacco use. While the Fagerström Test for Nicotine Dependence (FTND) is the most widely used measure of nicotine dependence, recent research has questioned its applicability for individuals with schizophrenia. The current study employed cognitive interviews to evaluate the FTND with smokers diagnosed with schizophrenia spectrum disorders, recruited from an acute inpatient psychiatry setting, and a comparison group of smokers recruited from the community. The groups were comparable on tobacco use variables and FTND scores. Detailed qualitative cognitive interviews indicated all subjects understood the FTND items. For both groups, the FTND missed nocturnal smoking, reported as weekly by 80% of patients and 47% of controls. Finishing other people's cigarettes also was under-reported on the FTND. Restrictions to smoking were common across groups. The cognitive interview methodology proved useful for understanding how individuals interpreted and answered the FTND items. Overall, the qualitative findings identified limitations in the FTND for both groups, with the limitations generally more pronounced among patients with schizophrenia.     

Applicability of the Fagerström Test for Nicotine Dependence in smokers with schizophrenia

Up to 90% of individuals with schizophrenia smoke cigarettes, and many show signs of heavy dependence. Although the severity of nicotine dependence is often measured by the six-item Fagerstrom Test for Nicotine Dependence (FTND), this measure, in its current form, may not be as appropriate in this population--or in others who's smoking is regulated by others--as in the general population due to differences in smoking patterns, living arrangements, and daily routines. These factors may produce an underestimate of nicotine dependence, which may have clinical implications for successful medical detoxification if the FTND scores are used to guide the dosage of nicotine replacement medication. Data indicate poor internal consistency reliability (alpha=.4581) and a factor pattern lacking simple structure (i.e., two nonmeaningful factors/components with substantial cross loadings) when administered to smokers with schizophrenia. Specific examples of problematic items and how these may contribute to an underestimate of tobacco dependence severity are discussed, as well as ways to modify the FTND to be more appropriate for this population.     

Predictors of 6-month tobacco abstinence among 1224 cigarette smokers treated for nicotine dependence

This study examined baseline characteristics associated with abstinence from tobacco 6 months after treatment for nicotine dependence. A total of 1224 cigarette smokers (619 females, 605 males) receiving clinical services for treatment of nicotine dependence between January 1, 1995 and June 30, 1997 were studied. The intervention involves a 45-min consultation with a nicotine dependence counselor. A treatment plan individualized to the patient's needs is then developed. The main outcome measure was the self-reported 7-day point prevalence abstinence from tobacco obtained by telephone interview 6-months after the consultation. A bootstrap resampling methodology for predictor variable selection was used to identify a set of multivariate predictors of 6-month tobacco abstinence. Five variables were multivariately associated with tobacco abstinence: male gender, no current psychiatric diagnosis, higher stage of change, longest duration of previous abstinence from tobacco of <1 or > or =30 days, and Fagerstr?m Test for Nicotine Dependence (FTND) score of < or =5. Assessment of these variables may be useful clinically by assisting health care providers in tailoring nicotine dependence interventions to enhance outcomes.     

The Fagerström test for nicotine dependence in two adult population samples-potential influence of lifetime amount of tobacco smoked on the degree of dependence

BACKGROUND: The Fagerstr?m test for nicotine dependence (FTND) has been widely used in clinical samples but seldom in population samples. Data are particularly lacking for a large range of ages. The goal was to describe the FTND sum score distribution in the adult population and to show potential variation according to the number of years of smoking. METHODS: Random adult population samples from two northern areas in Germany were used. Sample 1 included 1460 current smokers aged 20-64 years and sample 2 included 1135 current smokers aged 20-79 years. One cross-sectional and longitudinal and one cross-sectional study were conducted. The FTND was administered during face-to-face computer-aided interviews. RESULTS: The mean FTND sum score for those aged 20-64 was 3.2 among sample 1 and 2.5 among sample 2. The number of years of smoking and age did not affect the FTND sum score whereas it was positively correlated with the lifetime amount of tobacco smoked. CONCLUSIONS: Dependence according to the FTND does not increase with the number of years of smoking. Population-based interventions addressing the needs of dependent smokers across all age groups are needed.     

Smoking, nicotine dependence and psychiatric comorbidity--a population-based study including smoking cessation after three years

BACKGROUND: Evidence suggests that nicotine-dependent smokers are at increased risk for psychiatric comorbidity but general population data that included the number of nicotine dependence and withdrawal symptoms according to DSM-IV, the Fagerstrom Test for Nicotine Dependence (FTND), somatoform disorders and the number of psychiatric diagnoses are rare. The goal of the present study was to analyse relationships of smoking and nicotine dependence with psychiatric disease and whether psychiatric disease predicts the sustaining of smoking after three years. METHODS: Cohort study with a random adult population sample in a northern German region (N = 4075) including a baseline measurement of ever daily smokers aged 18-64 (n = 2458), a first follow-up of the current smokers at baseline (n = 1552) after 30 months and a second follow-up after 36 months. Measures included DSM-IV diagnoses by the Composite International Diagnostic Interview, FTND, smoking cessation by interview. RESULTS: Current daily smokers showed higher odds of a substance use disorder other than nicotine dependence compared with never smokers (odds ratio, OR, 4.6; confidence interval, CI, 2.9-7.2), affective (OR 1.8; CI 1.4-2.5), anxiety (OR 1.6; CI 1.2-2.0) or somatoform disorder (OR 1.4; CI 1.0-1.8). DSM-IV nicotine dependence and the FTND were positively related with the number of psychiatric diagnoses. Psychiatric comorbidity did not predict the maintenance of smoking or quitting. CONCLUSIONS: Findings of increased rates of mental disorders among smokers and nicotine-dependent smokers in the adult general population are supported by this study. The number of nicotine dependence and withdrawal symptoms are related to mental disorders. In addition, somatoform disorders show relationships with smoking similar to relationships with depressive or anxiety disorders. The intention to stop smoking should be proactively supported among these comorbid patients.     

Monoamine oxidases and tobacco smoking

Although nicotine has been identified as the main ingredient in tobacco responsible for aspects of the tobacco dependence syndrome, not all of the psychopharmacological effects of smoking can be explained by nicotine alone. Accumulating preclinical and clinical evidence has demonstrated that smoking also leads to potent inhibition of both types (A and B) of monoamine oxidase (MAO). Smokers have 30-40 % lower MAOB and 20-30 % lower MAOA activity than non-smokers. Reduced MAO activity in smokers has been shown by direct measures (platelets, positron emission tomographic studies) or by indirect measures (concentration of monoamine catabolites in plasma or CSF). We examine the hypothesis that chronic habitual smoking can be better understood in the context of two pharmacological factors: nicotine and reduced MAO activity. We speculate that MAO inhibition by compounds found in either tobacco or tobacco smoke can potentiate nicotine's effects. Based on this concept, more effective anti-smoking drug strategies may be developed. As a practical consequence of tobacco smoke's MAO-inhibitory properties, comparative psychiatric research studies need to screen and control for tobacco use.     

Link between facultative melanin and tobacco use among African Americans

Nicotine's affinity for melanin-containing tissues may result from its precursor function in melanin synthesis or the irreversible binding of melanin and nicotine. The objective of this study was to investigate a hypothesized association of tobacco use, dependence, and nicotine exposure with melanin pigmentation among African American smokers. A criterion-based sample was employed to collect data from a study of 147 adult African American current smokers. Carbon monoxide, saliva cotinine samples, and skin reflectance measures were obtained from each participant. Questionnaire data on demographic, sociological and behavioral questions related to smoking and skin color were gathered. The three dependent measures were the average number of cigarettes per day (CPD), Fagerström Test of Nicotine Dependence (FTND) score, and cotinine concentration. Analysis of variance, Pearson Correlations, and Multiple Linear Regression were conducted to analyze findings. The mean constitutive melanin reading was 56.3 and 66.5 for facultative melanin. Respondents on average smoked 19 CPD, had a mean FTND of 5.6, and a cotinine concentration of 435 ng/ml. Facultative melanin level was correlated with CPD and cotinine concentration in the bivariate analysis. The multiple linear regression results revealed that facultative melanin was significantly and positively related to CPD, the FTND, and cotinine. The results of this analysis support the hypothesis of a positive association between melanin levels and tobacco use, dependence, and exposure among African American smokers. This analysis may have important implications for research and interventions on tobacco dependence and disease outcomes. Further research on melanin and nicotine among African Americans as well as other population groups is warranted.     

Comparison of the Cigarette Dependence Scale with four other measures of nicotine involvement: Correlations with smoking history and smoking treatment outcome in smokers with substance use disorders

The Cigarette Dependence Scale (CDS) was developed to assess principal aspects of smoking dependence. In a French longitudinal survey, CDS showed stronger relationships to urge and change in smoking rate than the Fagerström Test for Nicotine Dependence (FTND). Neither measure predicted abstinence at follow-up in that survey but there was no treatment or cessation induction. The present study investigated concurrent and predictive validity of the CDS in a treatment population by comparing the CDS to the FTND and other measures of tobacco involvement as (1) a correlate of smoking and cessation history and (2) a predictor of short-term smoking abstinence among smokers with substance use disorders (SUD) receiving smoking treatment. Methods: Smokers (10 + cigarettes per day) in substance treatment received brief advice and nicotine patch for 8 weeks; half also received contingent vouchers for smoking cessation. Assessments were conducted pretreatment and 7, 14 and 30 days after treatment initiation, with abstinence verified biochemically. Results: At baseline (n = 305), the 12-item and 5-item CDS versions showed excellent and marginal reliability, respectively. FTND shared 43 and 61% of variance with CDS-12 and CDS-5, respectively. FTND and CDS scales correlated positively with cigarettes per day, and negatively with time to first cigarette, motivation to quit and age at first daily smoking. Only CDS correlated with the number of past quit attempts. Neither CDS nor FTND predicted abstinence within treatment, unlike the motivation measure and time to first cigarette. Conclusion: In moderate-heavy smokers with SUD in smoking treatment in the U.S., the CDS is largely equivalent to the FTND as an indicator of tobacco dependence but the CDS-5 is less reliable. Motivation was the most consistent predictor of outcome, and time to first cigarette was the only tobacco dependence measure that predicted smoking abstinence during treatment.     

A psychometric evaluation of the Fagerström Test for Nicotine Dependence in PTSD smokers

Rates of smoking among individuals with psychiatric conditions are greater than rates seen in the general population, yet little is known about the psychometric properties of commonly used nicotine dependence instruments among psychiatric smokers. This study examined the reliability, validity, and factor structure of the Fagerström Test for Nicotine Dependence (FTND) among psychiatric smokers. Results revealed that the FTND had good test–retest reliability, convergent validity, and discriminant validity. A factor-analytic examination converged on a two-factor solution, reflecting two correlated but separate processes related to nicotine dependence. In total, the results revealed that the FTND performs as well—from a psychometric perspective—with psychiatric smokers, as it does with nonpsychiatric smokers.     

Compulsive smoking: the development of a Rasch homogeneous scale of nicotine dependence

The unidimensionality of nicotine dependence has not been established firmly yet. The aim of this study was to assess the dimensionality of nicotine dependence, preferably meeting the strict assumptions of the Rasch model. First, we examined the validity of the Fagerstr?m Test for Nicotine Dependence (FTND) [Br. J. Addict. 86 (1991) 1119.] in 1525 smokers who participated in a national survey considering smoking behavior. Two factors were found, suggesting that the FTND does not measure a unidimensional construct. Factor analysis of 19 other dependence items in 512 smokers resulted in four factors of which three were interpretable: compulsive smoking, social problems due to smoking, and physical dependence. We focused on smoking compulsivity. This factor turned out to consist of a four-item Rasch homogeneous scale. Two items of the FTND with face validity of smoking compulsivity were found to fit into the scale. The results of Rasch analysis were in support of a continuum of compulsivity. Difficulty refraining from smoking in places where it is forbidden was found to indicate highest compulsivity. Several correlates with smoking compulsivity were found. We conclude that compulsive smoking is one important dimension of nicotine dependence, which may account for the considerable relapse of this disorder.     

Exploring brief measures of nicotine dependence for epidemiological surveys

A score > or = 6 in the Fagerstr?m Test for Nicotine Dependence (FTND), identifying high nicotine dependence, was compared with three briefer classifications: (1) Item 4: heavy smoking (more than 30 cigarettes per day); (2) Item 1: high early smoking (smoking within 30 min of waking up); and (3) a score > or = 4 by combining Items 1 and 4. The FTND scores from 1642 smokers from five samples in the US and Spain were analyzed. Heavy smoking had low sensitivity. High early smoking had low specificity. A score > or = 4 by combining Items 1 and 4 had relatively good sensitivity (94%) and specificity (88%). Researchers needing definition of nicotine dependence briefer than FTND may want to only use Items 1 and 4 of FTND with a cutting score > or = 4.     

The Nicotine Dependence Syndrome Scale in Finnish smokers

The Nicotine Dependence Syndrome Scale (NDSS) is a new multidimensional measure of nicotine dependence. The study aim was to examine the structure and heritability of the NDSS and its associations with nicotine dependence defined by FTND and DSM-IV criteria among Finnish smokers participating in an ongoing twin-family study. Adult twin pairs concordant for smoking from the Finnish Twin Cohort Study, and their siblings and parents were interviewed. Among 1370 smokers, the sum score of the NDSS (a summary measure of dependence) correlated moderately highly with FTND score (r=0.62). Subjects in the highest NDSS sum score groups were more likely to be nicotine dependent according to DSM-IV criteria compared with those in the lowest quintile (odds ratio=36.7, 95% confidence interval 13.0-103). In exploratory factor analysis, we derived three factors, named drive/priority, stereotypy/continuity and tolerance. The drive/priority factor correlated best with FTND (r=0.54). Genetic modeling showed no differences in the genetic architecture of NDSS or FTND by gender; the overall heritability estimate for NDSS was 0.30 (95% CI 0.06-0.47), and for FTND 0.40 (95% CI 0.23-0.55). The sum score of the NDSS is moderately highly associated with DSM-IV nicotine dependence as well as FTND. These analyses indicate that the NDSS functions well in a Finnish family-based sample and provide additional validation of a new scale developed to capture complex behavioural features of nicotine dependence.     

Smoking,nicotine dependence and nicotine intake by socio-economic status and marital status

Introduction

Low socio-economic status (SES) is strongly related to smoking, but studies examining the association of SES with nicotine dependence (ND) are scarce. The aim of this study was to examine the associations of SES and marital status with smoking, multiple measures of ND, and cotinine as a nicotine intake biomarker.

Methods

The sample comprised 1746 ever smokers, sampled from the National FINRISK 2007 Study, who had completed a tobacco specific questionnaire in addition to the standard clinical examination. The Fagerström Test for Nicotine Dependence (FTND), the Heaviness of Smoking Index (HSI), the Nicotine Dependence Syndrome Scale (NDSS), and the Hooked On Nicotine Checklist (HONC) were assessed, while plasma cotinine was measured as a biomarker of nicotine exposure in daily smokers. Univariate and multivariate associations were assessed by linear regression and multinomial logistic regression.

Results

In multivariate models, lower education was associated with higher FTND and HSI, income with HSI, and occupation with HSI (men only), FTND, HONC and NDSS scores. Lower education was related to higher cotinine levels among daily smokers, although the association diminished slightly after adjusting for daily smoking amount. Living without a spouse was associated with daily smoking and higher ND.

Conclusion

In this cross-sectional study low SES was linked with higher ND among current smokers, while low SES was associated with higher cotinine levels among daily smokers. Living alone was linked with higher ND. Longitudinal studies are warranted to further explore these associations. As lower SES smokers are more addicted they may need more targeted cessation services to succeed in quitting smoking.     

Income as a moderator of psychological stress and nicotine dependence among adult smokers

BackgroundPerceived stress and psychological distress are associated with more cigarette craving and withdrawal, higher nicotine dependence, and less success during quit attempts. Low income smokers have disproportionately higher rates of smoking and may be particularly vulnerable to the effects of stress on smoking dependence. The aim of the current study was to assess if lower income smokers have a stronger association between stress and nicotine dependence than higher income smokers.MethodsData were obtained from the Pennsylvania Adult Smoking Study, which included 351 daily smokers. Subjects completed PhenX Toolkit and other self-report measures of socioeconomic factors, the 10-item Perceived Stress Scale, Kessler Psychological Distress Scale (K6), Fagerstrom Test for Nicotine Dependence (FTND), and the Hooked on Nicotine Checklist (HONC). Moderation analyses using linear regression examined income-related differences in the association between stress and nicotine dependence.ResultsIncome groups were categorized by an annual household income of $50,000 based on visual-inspection of scatter plots of income by nicotine dependence. Compared to higher income smokers, lower income smokers had significantly higher mean levels of nicotine dependence on the FTND [3.74 vs. 4.79, p < 0.001], perceived stress [15.63 vs. 17.95, p = 0.004], and psychological distress [5.30 vs. 6.86, p = 0.001], respectively. There were interaction effects, such that lower income smokers had a strong, positive associations between FTND and perceived stress (B = −0.11, CI = −0.17 to −0.04, p = 0.002) and psychological distress (B = −0.13, CI = −0.25 to −0.02, p = 0.022) whereas no association was found in higher income smokers. No significant moderation effects were found for the HONC or when income groups were categorized by U.S. federal poverty level.ConclusionsThe results highlight that the relationship between increasing stress and FTND was found in lower but not higher income groups. Future research should examine socioeconomic, environmental and psychosocial factors that may facilitate increased smoking during stress-induced craving.     

Resequencing of Nicotinic Acetylcholine Receptor Genes and Association of Common and Rare Variants with the Fagerstr?m Test for Nicotine Dependence

Common single-nucleotide polymorphisms (SNPs) at nicotinic acetylcholine receptor (nAChR) subunit genes have previously been associated with measures of nicotine dependence. We investigated the contribution of common SNPs and rare single-nucleotide variants (SNVs) in nAChR genes to Fagerström test for nicotine dependence (FTND) scores in treatment-seeking smokers. Exons of 10 genes were resequenced with next-generation sequencing technology in 448 European-American participants of a smoking cessation trial, and CHRNB2 and CHRNA4 were resequenced by Sanger technology to improve sequence coverage. A total of 214 SNP/SNVs were identified, of which 19.2% were excluded from analyses because of reduced completion rate, 73.9% had minor allele frequencies <5%, and 48.1% were novel relative to dbSNP build 129. We tested associations of 173 SNP/SNVs with the FTND score using data obtained from 430 individuals (18 were excluded because of reduced completion rate) using linear regression for common, the cohort allelic sum test and the weighted sum statistic for rare, and the multivariate distance matrix regression method for both common and rare SNP/SNVs. Association testing with common SNPs with adjustment for correlated tests within each gene identified a significant association with two CHRNB2 SNPs, eg, the minor allele of rs2072660 increased the mean FTND score by 0.6 Units (P=0.01). We observed a significant evidence for association with the FTND score of common and rare SNP/SNVs at CHRNA5 and CHRNB2, and of rare SNVs at CHRNA4. Both common and/or rare SNP/SNVs from multiple nAChR subunit genes are associated with the FTND score in this sample of treatment-seeking smokers.     

Motivational factors related to quitting smoking among prisoners during a smoking ban

Motivational factors and initial stages of change (precontemplation vs. contemplation) were investigated among incarcerated male smokers forced to quit smoking due to a statewide smoking ban. All smokers completed a baseline questionnaire, which assessed smoking history, nicotine dependence [Fagerstrom Test for Nicotine Dependence (FTND)], nicotine withdrawal [Hughes-Hatsukami Withdrawal Scale (HHWS)], and depression [Center for Epidemiological Studies on Depression (CES-D)]. These measures were given again 4 days (Time 2) and 1 month (Time 3) following the smoking ban. At baseline (n=314), 31.2% of smokers were contemplating quitting within 6 months (contemplators), while the majority of smokers (68.8%) indicated they had not considered quitting (precontemplators). Contemplators at Time 2 reported more success with quitting smoking than precontemplators, although this was no longer significant by Time 3. Logistic regression was used to determine the probability of determining initial stages of change based on demographic and smoking history variables. Smokers in precontemplation scored higher on the FTND, reported less agreement with the smoking policy at baseline, reported more difficulty with their previous quit attempts, and reported increased smoking in anticipation of the smoking ban. The risk of being a precontemplator was over twice as high for smokers who reported increasing the amount they smoked prior to the smoking ban (odds ratio=2.42). Overall, this model correctly classified 70.7% of the smokers. This suggests that initial stages of change plays an important role in eventual quitting even in environments in which smoking has been recently prohibited.     

5-羟色胺转运体基因与中国男性吸烟行为的关联研究

目的:探讨5-羟色胺转运体基因启动子区多态性(5-HTTLPR)与中国成年男性吸烟行为之间的关系。方法:采用吸烟行为相关因素问卷、艾森克人格问卷(EPQ)及尼古丁依赖评定问卷(FTND)评定中国成年男性不吸烟者及吸烟者共1012例,收集血标本采用聚合酶链反应技术检测5-HTTLPR的多态性,使用SPSS 13.0统计软件及UNPHASE遗传分析软件进行统计分析。结果:未发现5-HTTLPR位点与吸烟行为的不同阶段包括吸烟启动(P=0.922)、吸烟维持(P=0.309)和尼古丁依赖(P=0.701)存在关联。进一步分层分析发现:携带S等位基因(SS+SL)的吸烟者中神经质人格特质与FTND总分正相关(r=0.118,P=0.004),与吸烟严重指数(HSI)正相关(r=0.102,P=0.013),与平均每天的吸烟量正相关(r=0.108,P=0.008),与第一次吸烟的年龄负相关(r=-0.117,P=0.004)。结论:5-HTT基因可能通过调节神经质人格特质与吸烟行为之间的关系而间接影响吸烟行为。