Nicotine dependence, depression, and gender: characterizing phenotypes based on withdrawal discomfort, response to smoking, and ability to abstain

Sex Differences in Withdrawal-Induced Anxiety in Rats After Exposure to Tobacco Smoke

Nicotine, a component of cigarettes, possesses strong reinforcing properties and improves cognitive function, which can lead to dependence. Upon cigarette smoking cessation, withdrawal symptoms occur and may cause an individual to relapse. Affective withdrawal symptoms, such as anxiety, is of great concern as studies have shown its ability to cause relapse in men and women. In this in vivo study, anxiety resulting from smoking cessation after 2-day smoke-free intervals per week for the duration of 4 weeks was investigated in 8 male and 8 female rats after their exposure to cigarette smoke compared to unexposed control rats (8 males and 8 female rats). The anxiety in rats during smoke-free intervals was investigated using an elevated plus-maze (EPM), open-field (OF), and light/dark test (LD). In all tests male rats exhibited significantly higher anxiety symptoms compared to female rats during nicotine withdrawal, despite control rats showing no differences. In the EPM, male rats spent less time in open arm as well having as lower number of crossings than female rats. As for the OFT, the amount of time spent in the center of the open field was also lower in male rats than female rats. In the LD test, the time spent in the light chamber and the latency (delay) to enter the dark chamber was lower in male rats compared to female rats. Our study showed that male rats show greater nicotine withdrawal effects, in terms of anxiety-like behavior than female rats.

Dynamic effects of ventral hippocampal NRG3/ERBB4 signaling on nicotine withdrawal-induced responses

Tobacco smoking remains a leading cause of preventable death in the United States, with approximately a 5% success rate for smokers attempting to quit. High relapse rates have been linked to several genetic factors, indicating that the mechanistic relationship between genes and drugs of abuse is a valuable avenue for the development of novel smoking cessation therapies. For example, various single nucleotide polymorphisms (SNPs) in the gene for neuregulin 3 (NRG3) and its cognate receptor, the receptor tyrosine-protein kinase erbB-4 (ERBB4), have been linked to nicotine addiction. Our lab has previously shown that ERBB4 plays a role in anxiety-like behavior during nicotine withdrawal (WD); however, the neuronal mechanisms and circuit-specific effects of NRG3-ERBB4 signaling during nicotine and WD are unknown. The present study utilizes genetic, biochemical, and functional approaches to examine the anxiety-related behavioral and functional role of NRG3-ERBB4 signaling, specifically in the ventral hippocampus (VH) of male and female mice. We report that 24hWD from nicotine is associated with altered synaptic expression of VH NRG3 and ERBB4, and genetic disruption of VH ErbB4 leads to an elimination of anxiety-like behaviors induced during 24hWD. Moreover, we observed attenuation of GABAergic transmission as well as alterations in Ca2+-dependent network activity in the ventral CA1 area of VH ErbB4 knock-down mice during 24hWD. Our findings further highlight contributions of the NRG3-ERBB4 signaling pathway to anxiety-related behaviors seen during nicotine WD.

Dynamic Effects of Ventral Hippocampal NRG3/ERBB4 Signaling on Nicotine Withdrawal-Induced Responses

Tobacco smoking remains a leading cause of preventable death in the United States, with a less than 5% success rate for smokers attempting to quit. High relapse rates have been linked to several genetic factors, indicating that the mechanistic relationship between genes and drugs of abuse is a valuable avenue for the development of novel smoking cessation therapies. For example, various single nucleotide polymorphisms (SNPs) in the gene for neuregulin 3 (NRG3) and its cognate receptor, the receptor tyrosine-protein kinase erbB-4 (ERBB4), have been linked to nicotine addiction. Our lab has previously shown that ERBB4 plays a role in anxiety-like behavior during nicotine withdrawal (WD); however, the neuronal mechanisms and circuit-specific effects of NRG3-ERBB4 signaling during nicotine and WD are unknown. The present study utilizes genetic, biochemical, and functional approaches to examine the anxiety-related behavioral and functional role of NRG3-ERBB4 signaling, specifically in the ventral hippocampus (VH). We report that 24hWD from nicotine is associated with altered synaptic expression of VH NRG3 and ERBB4, and genetic disruption of VH ErbB4 leads to an elimination of anxiety-like behaviors induced during 24hWD. Moreover, we observed attenuation of GABAergic transmission as well as alterations in Ca2+-dependent network activity in the ventral CA1 area of VH ErbB4 knock-down mice during 24hWD. Our findings further highlight contributions of the NRG3-ERBB4 signaling pathway to anxiety-related behaviors seen during nicotine WD.

Effects of regular cannabis and nicotine use on acute stress responses: chronic nicotine, but not cannabis use, is associated with blunted adrenocortical and cardiovascular responses to stress

RATIONALE

Cannabis is one of the most prevalent substances used by tobacco smokers and, in light of the growing list of states and territories legalizing cannabis, it is expected that co-use of cannabis and nicotine will escalate significantly and will lead to continuing challenges with tobacco use.

OBJECTIVES

This study was conducted to examine the interactive effects of chronic cannabis and nicotine use on adrenocortical, cardiovascular, and psychological responses to stress and to explore sex differences in these effects.

METHODS

Participants (N = 231) included cannabis-only users, nicotine-only users, co-users of both substances, and a non/light-user comparison group. After attending a medical screening session, participants completed a laboratory stress session during which they completed measures of subjective states, cardiovascular responses, and salivary cortisol during baseline (rest) and after exposure to acute stress challenges.

RESULTS

Nicotine use, but not cannabis use, was associated with blunted cortisol and cardiovascular responses to stress across both men and women. Men exhibited larger cortisol responses to stress than women. Co-users had significantly larger stress-related increases in cannabis craving than cannabis-only users. Cannabis users reported smaller increases in anxiety during stress than cannabis non/light-users, and both male nicotine-only users and male cannabis-only users experienced significantly smaller increases in stress than their non/light-user control counterparts.

CONCLUSIONS

This study replicates and extends earlier research on the impacts of sex and nicotine use on stress responses, and it provides novel findings suggesting that when co-used with nicotine, cannabis use may not confer additional alterations to physiological nor subjective responses to stress. Co-use, however, was associated with enhanced stress-related craving for cannabis.

Perceived Disease Risk of Smoking, Barriers to Quitting, and Cessation Intervention Preferences by Sex Amongst Homeless Adult Concurrent Tobacco Product Users and Conventional Cigarette-Only Users

Adults experiencing homelessness smoke conventional cigarettes and engage in concurrent tobacco product use at very high rates; however, little is known about how use patterns, perceived disease risk, barriers to quitting smoking, and smoking cessation intervention preferences differ by sex in this group. Participants comprised a convenience sample of 626 adult conventional cigarette smokers experiencing homelessness. Participants self-reported their sex, smoking history, mental health and substance use diagnosis history, other concurrent tobacco product use (CU), disease risk perceptions, perceived barriers to quitting smoking, and preferences regarding tobacco cessation interventions via a computer-administered survey. CU rates were 58.1% amongst men and 45.3% amongst women smokers. In both sexes, CUs started smoking earlier (p-values < 0.001) and were more likely to have been diagnosed with a non-nicotine substance use disorder (p-values < 0.014) relative to cigarette-only users. Among men only, CUs were younger, smoked more cigarettes per day and were more likely to identify as non-Hispanic White (p-values < 0.003) than cigarette-only users. Additionally, male CUs reported a greater risk of developing ≥1 smoking-related disease if they did not quit for good; were more likely to endorse craving cigarettes, being around other smokers, habit, stress/mood swings, and coping with life stress as barriers for quitting smoking; and were less likely to prefer medications to quit smoking relative to male cigarette-only users (p-values < 0.04). On the other hand, female CUs reported a greater risk of developing ≥1 smoking-related disease even if they quit for good; were more likely to endorse stress/mood swings and coping with life stress as barriers for quitting smoking relative to female cigarette-only users (p-values < 0.05); and did not differentially prefer one cessation medication over another. Overall, findings confirm high rates of CU among both sexes, characterize those who may be more likely to be CUs, and reveal opportunities to educate men and women experiencing homeless on the benefits of evidence-based interventions for smoking cessation.

Association of depression symptom level with smoking urges, cigarette withdrawal, and smoking reinstatement: A preliminary laboratory study

BACKGROUND

Cigarette smoking urges, withdrawal, and smoking reinstatement may be especially relevant to people with elevated depression symptoms who smoke. This laboratory study aimed to assess relations between depression symptom level and smoking urges for reward and relief, cigarette withdrawal, and smoking reinstatement in people who smoke cigarettes daily during acute abstinence and while smoking as usual.

METHODS

Participants with low (n = 51) or elevated (n = 29) baseline depression symptoms underwent two counterbalanced laboratory sessions (i.e., abstinent, non-abstinent). At each session, they completed subjective measures of smoking urges for reward and relief, and withdrawal. They also completed a laboratory smoking reinstatement task measuring whether they would delay smoking and the number of cigarettes smoked.

RESULTS

The elevated depression symptom group reported significantly higher withdrawal (p = .01) and smoked more cigarettes than the low depression symptoms group during the smoking reinstatement task self-administration period at the abstinent session (p = .04). Smoking urges for reward and relief were not significantly different by depression symptom group. There were no significant interactions of depression and abstinence with any outcomes.

CONCLUSIONS

As outcomes were measured at both an abstinent and non-abstinent session, findings identify factors for people with elevated depression symptoms who smoke which may drive smoking behavior and impede smoking cessation efforts. This study provides evidence that people with elevated depression symptoms who smoke may need additional/more pharmacological or behavioral smoking cessation aids targeted at reducing withdrawal and number of cigarettes smoked.

Tobacco Use Disorder

Tobacco use disorder is highly prevalent; more than a billion individuals use tobacco worldwide. Popular views on the addictive potential of tobacco often underestimate the complex neural adaptations that underpin continued use. Although sometimes trivialized as a minor substance, effects of nicotine on behavior lead to profound morbidity over a lifetime of exposure. Innovations in processing have led to potent forms of tobacco and delivery devices. Proactive treatment strategies focus on pharmacotherapeutic interventions. Innovations on the horizon hold promise to help clinicians address this problem in a phenotypically tailored manner. Efforts are needed to prevent tobacco use for future generations.

Nicotine preference and affective behavior of Cd81 knockout mice

RATIONALE

Cd81 -/- (knockout) mice have previously been reported to have reduced cocaine preference and increased striatal dopamine content and dopamine turnover, but normal learning and memory in the Morris water maze. The effects of Cd81 on other behaviors and drugs of abuse have not been investigated.

OBJECTIVES AND METHODS

We measured the effects of Cd81 -/- in a modified two-bottle choice test for nicotine, as well as in somatic signs of nicotine withdrawal, four tests of affective behavior, and tyrosine hydroxylase gene expression assays.

RESULTS

We found that Cd81 loss-of-function significantly increased voluntary nicotine consumption and somatic signs of nicotine withdrawal. Nicotine consumption of Cd81 -/- female mice increased for 3 weeks and then remained relatively stable for the next 5 weeks, suggesting that their nicotine consumption continued to be limited by aversion to higher nicotine doses. Cd81 -/- also produced a dramatic and significant increase in struggling in the forced swim test and a significant increase in the time spent in the light chamber of the light/dark box. The elevated plus maze and the tail suspension test did not show a main effect of genotype. Therefore, we conclude that Cd81 did not have an overall effect on anxiety- or depression-like behavior. Tyrosine hydroxylase mRNA levels were unchanged.

CONCLUSIONS

Cd81 knockouts have a strongly increased nicotine preference, plus a proactive response to specific stressful situations. Together with reports of increased striatal dopamine content and anecdotal reports of increased aggressiveness, these provide intriguing parallels to some aspects of post-traumatic stress disorder.

Sexual identity differences in biomarkers of tobacco exposure among women in a national sample

BACKGROUND

Sexual minority women are consistently at increased risk for tobacco use compared to heterosexual women. Neither biomarkers of nicotine exposure nor biomarkers of tobacco toxicant exposure have been examined by sexual identity.

METHODS

This study used interview and biomarker data from women in the biomarker core sample of Wave 1 of the Population Assessment of Tobacco and Health (PATH) study (2013-2014; n = 4930). We examined associations of sexual identity with nicotine exposure (measured with urinary cotinine and TNE-2) and with tobacco-specific nitrosamines (measured with urinary NNAL). Multivariable regression modeling was used to examine these associations among the full biomarker core sample, among past 30-day tobacco users, and among exclusive established cigarette users before and after controlling for tobacco use quantity and intensity.

RESULTS

In the full biomarker sample of women, prior to adjusting for tobacco use quantity and intensity, bisexual women had significantly higher cotinine, TNE-2, and NNAL levels compared to heterosexual women. Among exclusive established cigarette users, gay/lesbian women had significantly higher NNAL compared to heterosexual women prior to adjusting for tobacco quantity and intensity. No differences by sexual identity were found after adjusting for tobacco use quantity and intensity.

CONCLUSIONS

This is the first study to demonstrate differences in biological markers of tobacco exposure by sexual identity among women in the U.S. This has important public health implications as greater exposure to both nicotine and to tobacco-specific nitrosamines are strongly linked to cancer risk.

Translational Research in Nicotine Addiction

While commendable strides have been made in reducing smoking initiation and improving smoking cessation rates, current available smoking cessation treatment options are still only mildly efficacious and show substantial interindividual variability in their therapeutic responses. Therefore, the primary goal of preclinical research has been to further the understanding of the neural substrates and genetic influences involved in nicotine's effects and reassess potential drug targets. Pronounced advances have been made by investing in new translational approaches and placing more emphasis on bridging the gap between human and rodent models of dependence. Functional neuroimaging studies have identified key brain structures involved with nicotine-dependence phenotypes such as craving, impulsivity, withdrawal symptoms, and smoking cessation outcomes. Following up with these findings, rodent-modeling techniques have made it possible to dissect the neural circuits involved in these motivated behaviors and ascertain mechanisms underlying nicotine's interactive effects on brain structure and function. Likewise, translational studies investigating single-nucleotide polymorphisms (SNPs) within the cholinergic, dopaminergic, and opioid systems have found high levels of involvement of these neurotransmitter systems in regulating the reinforcing aspects of nicotine in both humans and mouse models. These findings and coordinated efforts between human and rodent studies pave the way for future work determining gene by drug interactions and tailoring treatment options to each individual smoker.

Demographic and psychological moderators of the relationship between neighborhood cigarette advertising and current smoking in New York City

BACKGROUND

Tobacco advertising in retailers influences smoking, but little research has examined how this relationship differs among population subgroups. This study merged data on neighborhood cigarette advertising with geocoded survey data to assess the association between advertising prevalence and current smoking among New York City (NYC) residents, and whether demographic and psychological characteristics moderate this relationship.

METHODS

Audit data from a stratified, random sample of 796 NYC tobacco retailers generated neighborhood prevalence estimates of cigarette advertising, which were linked with unweighted 2017 NYC Community Health Survey data (n = 7837 adult respondents with residential geocodes). Multilevel regression estimated adjusted odds ratios (aOR) of current smoking by level of neighborhood cigarette advertising (quartiles). Interactions assessed differences in this relationship by demographic characteristics and current depression (analyses conducted in 2019).

RESULTS

There was no main effect of advertising on smoking status or significant interactions with demographic variables, but current depression was an effect modifier (p = 0.045). Cigarette advertising was associated with current smoking among those with current depression (p = 0.023), not those without (p = 0.920). Specifically, respondents with depression who resided in neighborhoods in the highest quartile for cigarette advertising prevalence had higher odds of current smoking, compared to those living in the lowest advertising quartile [aOR: 1.72 (1.04, 2.86)].

CONCLUSION

Retail cigarette advertising may serve as an environmental cue to smoke among adults with depression. Efforts to restrict or counteract this practice, such as the development of community-level public health interventions and counter-marketing programs, may particularly benefit those with depression and, perhaps, other mental health disorders.

Smoking in relation to anxiety and depression: Evidence from a large population survey: The HUNT study

Smoking is reported to be associated with depression and anxiety. The present study (a) examines these associations taking comorbidity into account, (b) investigates possible confounders, (c) examines how former smokers compared to current and never-smokers in terms of anxiety and depression, and if anxiety and depression decline by time since cessation. Participants (66%) aged 20–89 years in a population-based health survey (N = 60,814) were screened employing the HADS. (a) The association with smoking was strongest in comorbid anxiety depression, followed by anxiety, and only marginal in depression. Associations were stronger in females and younger participants. (b) Variables partly accounting for the association comprised somatic symptoms, socio-demographics, alcohol problems, and low physical activity. (c) Anxiety and depression were most common in current smokers, followed by quitters, and then never-smokers. No decline in anxiety or depression was found with time since cessation. Previous studies of associations between depression and smoking might have overestimated the association when ignoring comorbid anxiety.

Lack of utility of cigarettes per day cutoffs for clinical and laboratory smoking research

BACKGROUND

Most clinical and laboratory smoking research studies require that participants smoke at a certain level to be eligible for enrollment. However, there is limited evidence that use of these cutoffs differentiates groups of smokers along clinically meaningful criteria.

METHODS

Using receiver operating characteristic curves, we analyzed data from daily smokers in the National Epidemiologic Study of Alcohol Use and Related Conditions - III (NESARC-III) to examine the utility of smoking rates for determining whether participants met DSM-5 criteria for tobacco use disorder, experienced nicotine withdrawal or had a history of failed quit attempts. We also examined whether relationships between these variables differed as a function of key sample characteristics.

RESULTS

Smoking rate exhibited a weak relationship with the presence of tobacco use disorder (AUC = 0.664), whether individuals experience nicotine withdrawal (AUC = 0.672) and whether individuals had a history of failed quit attempts (AUC = 0.578). The relationship between smoking rate and a history of failed quit attempts was weaker for women than men (p < .05). Otherwise, utility did not differ as a function of sex, race/ethnicity, education, income, or use of multiple tobacco products. Optimal cutoffs varied somewhat across indices, but the largest number of correct classifications occurred at very low smoking rates.

CONCLUSIONS

Researchers should consider abandoning the use of smoking rate cutoffs to determine study eligibility. If smoking rate cutoffs are used, a rationale should be presented along with justification for the specific cutoff chosen.

Metabotropic Glutamate Receptors 2 and 3 as Targets for Treating Nicotine Addiction

Tobacco smoking, driven by the addictive properties of nicotine, continues to be a worldwide health problem. Based on the well-established role of glutamatergic neurotransmission in drug addiction, novel medication development strategies seek to halt nicotine consumption and prevent relapse to tobacco smoking by modulating glutamate transmission. The presynaptic inhibitory metabotropic glutamate receptors 2 and 3 (mGluR2/3) are key autoreceptors on glutamatergic terminals that maintain glutamate homeostasis. Accumulating evidence suggests the critical role of mGluR2/3 in different aspects of nicotine addiction, including acquisition and maintenance of nicotine taking, nicotine withdrawal, and persistent nicotine seeking even after prolonged abstinence. The involvement of mGluR2/3 in other neuropsychiatric conditions, such as anxiety, depression, schizophrenia, Alzheimer's disease, Parkinson's disease, and pain, provides convincing evidence suggesting that mGluR2/3 may provide an effective therapeutic approach for comorbidity of smoking and these conditions. This focused review article highlights that mGluR2/3 provide a promising target in the search for smoking cessation medication with novel mechanisms of actions that differ from those of currently U.S. Food and Drug Administration-approved pharmacotherapies.

Depressive symptoms in the trajectory of craving during smoking cessation treatment: A latent growth curve model

BACKGROUND

Depressive symptoms and craving are related to smoking maintenance; however, little is known about the association between trajectories of depressive symptoms and smoking craving after quitting.

OBJECTIVES

We examined if depressive symptom change relates to change in craving following smoking cessation treatment.

METHODS

Participants were 362 (64.1% female; 35.9% male) adult treatment seeking smokers who quit smoking after treatment. Depressive symptoms and craving trajectories were evaluated during smoking cessation treatment until 6 months follow-up. A latent growth curve model was used to study the correlation between trajectories.

RESULTS

Depressive symptoms and smoking craving reduced significantly after quitting. Change in depressive symptoms was significantly related to change in craving symptoms over time.

CONCLUSIONS

Quitting smoking was related to a reduction in depressive symptoms and craving. Clinically, the reduction of depressive symptoms is associated with reduce craving. The data suggest depression plays an important role in craving change following treatment.

Stress and Addiction: When a Robust Stress Response Indicates Resiliency

OBJECTIVE

Stress reactivity research has traditionally focused on the idea that exaggerated responses to stress may have adverse effects on health. Accumulating evidence suggests that attenuated responses to stress and delayed recovery may also be problematic.

METHODS

This review focuses on the role of the stress response of the hypothalamic-pituitary-adrenocortical axis, the endogenous opioid system, and the cardiovascular system in hypertension, pain perception, and addictive behaviors. Results from multiple methods of assessment and stress paradigms conducted in our laboratory over the past two decades are integrated with research from other investigators and with existing theories.

RESULTS

Research indicates that exaggerated biological and physiological responses to stress and attenuated pain perception are associated with hypertension and risk for cardiovascular diseases. This research complements work linking reduced stress responses with enhanced pain sensitivity and discomfort. Multiple studies have also demonstrated that an attenuated stress response is linked to exacerbation of withdrawal symptoms and relapse in nicotine addiction. Evidence indicates important moderators (i.e., sex, personality traits, and early life adversity) and hypothalamic-pituitary-adrenocortical- and endogenous opioid system-related mechanisms in the altered response to stress. I integrate these findings in a conceptual model emphasizing that robust stress responses in the context of addiction and relapse should be considered as a marker of resiliency.

CONCLUSIONS

A blunted stress response may indicate long-term physiological dysregulation that could usher harmful consequences for cardiovascular disease, pain perception, and addictive disorders. The impact of dysregulation is influenced by multiple individual and situational factors that should be considered in evaluating the clinical significance of stress response dysregulation.

The Interaction of Depressive Symptoms and Hazardous Drinking in Relation to Tobacco Craving Among Treatment Seeking Depressed Smokers: Sex Differences

OBJECTIVES

The present study sought to address whether there is sex effect in the interactive effect between depressive symptoms and hazardous drinking in the prediction of smoking craving after cognitive-behavioral smoking cessation treatment among those with at least mild depression.

METHODS

Participants (n = 114, mean age 42.0, SD = 9.73, 64% women) were treatment-seeking smokers who attended 6 weekly 1-hour sessions involving psychological treatment for cessation. Participants reported depressive symptoms and alcohol use at baseline and reported craving at baseline and after treatment.

RESULTS

Results indicated that there was a statistically significant 3-way interaction (depression by alcohol use by sex) for smoking craving (B = -0.30, standard error [SE] = 0.14, P = 0.042) and appetitive craving (B = -.21, SE = 0.09, P = 0.031), but not negative reinforcement craving. The form of the significant interactions indicted that higher levels of depressive symptoms and alcohol use were related to greater levels of craving at the end of treatment only among men.

CONCLUSIONS

The current findings provide novel empirical evidence suggesting that there is a clinically relevant interplay between depressive symptoms and alcohol use regarding general craving and appetitive craving among male treatment-seeking smokers. Although the present results should be replicated in larger samples, this type of research can inform the development of sex-specific interventions for smoking cessation.

Acculturation, Depression, and Smoking Cessation: a trajectory pattern recognition approach

BACKGROUND

Korean Americans are known for a high smoking prevalence within the Asian American population. This study examined the effects of acculturation and depression on Korean Americans' smoking cessation and abstinence.

METHODS

This is a secondary data analysis of a smoking cessation study that implemented eight weekly individualized counseling sessions of a culturally adapted cessation intervention for the treatment arm and a standard cognitive behavioral therapy for the comparison arm. Both arms also received nicotine patches for 8 weeks. A newly developed non-parametric trajectory pattern recognition model (MI-Fuzzy) was used to identify cognitive and behavioral response patterns to a smoking cessation intervention among 97 Korean American smokers (81 men and 16 women).

RESULTS

Three distinctive response patterns were revealed: (a) Culturally Adapted (CA), since all identified members received the culturally adapted intervention; (b) More Bicultural (MB), for having higher scores of bicultural acculturation; and (c) Less Bicultural (LB), for having lower scores of bicultural acculturation. The CA smokers were those from the treatment arm, while MB and LB groups were from the comparison arm. The LB group differed in depression from the CA and MB groups and no difference was found between the CA and MB groups. Although depression did not directly affect 12-month prolonged abstinence, the LB group was most depressed and achieved the lowest rate of abstinence (LB: 1.03%; MB: 5.15%; CA: 21.65%).

CONCLUSION

A culturally adaptive intervention should target Korean American smokers with a high level of depression and a low level of biculturalism to assist in their smoking cessation.

TRIAL REGISTRATION

NCT01091363. Registered 21 March 2010.

Distinct Roles of CREB Within the Ventral and Dorsal Hippocampus in Mediating Nicotine Withdrawal Phenotypes

Addiction to nicotine and the inability to quit smoking are influenced by genetic factors, emphasizing the importance of understanding how genes and drugs of abuse mechanistically impact each other. One well-characterized protein responsible for regulating both response to drugs and gene expression is the transcription factor CREB (cAMP-responsive element binding protein). Previous work indicates that hippocampal-specific alterations in CREB signaling and synaptic plasticity may underlie certain nicotine withdrawal phenotypes. However, the structure of the hippocampus possesses dorsal and ventral subregions, each differing in behavioral, anatomic and gene expression characteristics. This study examines the effects of CREB deletion specifically in the ventral or dorsal hippocampus of animals chronically treated with saline, nicotine, or undergoing 24 h withdrawal. After region-specific viral injections of AAV-GFP or AAV-CRE in CREB^loxP/loxP animals, behavioral testing measured anxiety levels, using the Novelty-Induced Hypophagia test, and cognition, using a contextual fear conditioning paradigm. Deletion of CREB in the ventral, but not dorsal, hippocampus resulted in amelioration of nicotine withdrawal-induced anxiety-like behavior in the Novelty-Induced Hypophagia test. In contrast, CREB deletion in the dorsal hippocampus resulted in learning and memory deficits in fear conditioning, whereas CREB deletion in the ventral hippocampus showed an enhancement in learning. Gene expression analysis showed differential treatment- and region-dependent alterations of several CREB target genes that are well-known markers of neuroplasticity within the hippocampus. Collectively, these data provide persuasive evidence towards the distinct roles of CREB within the dorsal and ventral hippocampus separately in mediating select nicotine withdrawal phenotypes.

Hazardous Alcohol Drinking as Predictor of Smoking Relapse (3-, 6-, and 12-Months Follow-Up) by Gender

Diverse studies have found a relation between alcohol consumption and smoking relapse. Few studies have analyzed the relation of smoking relapse with pretreatment alcohol consumption and gender differences. The main purpose of this study is to analyze the influence of alcohol consumption in smoking relapse over 12 months (3-, 6-, and 12-months follow-up) and to determine possible gender differences. The sample included 374 smokers who quit smoking by participating in a psychological smoking cessation treatment. We assessed hazardous pretreatment alcohol drinking (AUDIT), cigarette consumption (FTND; number of cigarettes) and sociodemographic variables. Higher scores on hazardous pretreatment alcohol drinking predict smoking relapse at 3-, 6-, and 12-months after smoking cessation. In males, higher scores on hazardous pretreatment alcohol drinking predict relapse at 6 and at 12 months. In females, higher scores on hazardous pretreatment alcohol drinking predict tobacco relapse at 3 months. Hazardous pretreatment alcohol drinking predicts relapse at all intervals after smoking cessation (3-, 6-, and 12-months follow-up). However, the influence of hazardous pretreatment alcohol drinking on smoking relapse differs as a function of gender, as it is a short-term predictor in women (3 months) and a long-term predictor in men (6 and 12 months).

Gender differences in self-reported withdrawal symptoms and reducing or quitting smoking three years later: A prospective, longitudinal examination of U.S. adults

BACKGROUND

Little is known about gender differences in withdrawal symptoms among smokers in the community. This study used longitudinal epidemiologic data to examine gender differences in current smokers' report of withdrawal symptoms during past quit attempts and the relationship between withdrawal symptoms and the odds of reducing or quitting smoking three years later.

METHODS

Data were drawn from the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC; Wave 1, 2001-2001, n=43,093; Wave 2, 2004-2005, n=34,653). Analyses were conducted on respondents who reported current daily cigarette smoking at Wave 1 (n=6911). Withdrawal symptoms during past quit attempts were assessed at Wave 1. Current smoking status was assessed at Wave 2.

RESULTS

Wave 1 current smoking women, compared to men, were more likely to endorse any withdrawal symptoms, withdrawal-related discomfort, and withdrawal-related relapse (ps<0.0001). Women endorsed a greater number of withdrawal symptoms than men (M=2.37, SE=0.05 versus M=1.78, SE=0.04; p<0.0001). The odds of reducing and quitting smoking were significantly lower for respondents who reported any Wave 1 withdrawal symptoms, withdrawal-related discomfort, and withdrawal-related relapse. These relationships did not differ for women versus men. Among men, the odds of reducing smoking at Wave 2 decreased significantly with each cumulative withdrawal symptom compared to women (β interaction=0.87; p=0.01).

CONCLUSIONS

Women were more likely to report withdrawal while the relationship between withdrawal symptoms and decreased likelihood of reducing smoking was stronger in men. Identifying gender differences in withdrawal can help develop strategies to help reduce withdrawal for both men and women.

A gene-by-sex interaction for nicotine reward: evidence from humanized mice and epidemiology

It has been proposed that vulnerability to nicotine addiction is moderated by variation at the μ-opioid receptor locus (OPRM1), but results from human studies vary and prospective studies based on genotype are lacking. We have developed a humanized mouse model of the most common functional OPRM1 polymorphism rs1799971_A>G (A118G). Here we use this model system together with a cohort of German youth to examine the role of the OPRM1 A118G variation on nicotine reward. Nicotine reinforcement was examined in the humanized mouse model using i.v. self-administration. Male (n=17) and female (n=26) mice homozygous either for the major human A allele (AA) or the minor G allele (GG) underwent eight daily 2 h sessions of nicotine self-administration. Furthermore, male (n=104) and female (n=118) subjects homozygous for the A allele or carrying the G allele from the Mannheim Study of Children at Risk were evaluated for pleasurable and unpleasant experiences during their initial smoking experience. A significant sex-by-genotype effect was observed for nicotine self-administration. Male 118GG mice demonstrated higher nicotine intake than male 118AA mice, suggesting increased nicotine reinforcement. In contrast, there was no genotype effect in female mice. Human male G allele carriers reported increased pleasurable effects from their first smoking experience, as compared to male homozygous A, female G and female homozygous A allele carriers. The 118G allele appears to confer greater sensitivity to nicotine reinforcement in males, but not females.

Advances in nicotine research in Addiction Biology

The aim of Addiction Biology is to advance our understanding of the action of drugs of abuse and addictive processes via the publication of high-impact clinical and pre-clinical findings resulting from behavioral, molecular, genetic, biochemical, neurobiological and pharmacological research. As of 2013, Addiction Biology is ranked number 1 in the category of Substance Abuse journals (SCI). Occasionally, Addiction Biology likes to highlight via review important findings focused on a particular topic and recently published in the journal. The current review summarizes a number of key publications from Addiction Biology that have contributed to the current knowledge of nicotine research, comprising a wide spectrum of approaches, both clinical and pre-clinical, at the cellular, molecular, systems and behavioral levels. A number of findings from human studies have identified, using imaging techniques, alterations in common brain circuits, as well as morphological and network activity changes, associated with tobacco use. Furthermore, both clinical and pre-clinical studies have characterized a number of mechanistic targets critical to understanding the effects of nicotine and tobacco addiction. Together, these findings will undoubtedly drive future studies examining the dramatic impact of tobacco use and the development of treatments to counter nicotine dependence.

Predicted Impact of Nicotine Reduction on Smokers with Affective Disorders

OBJECTIVES

In 2009 the FDA acquired the authority to reduce the nicotine content in cigarettes if appropriate for public health, prompting research to evaluate the implications of this policy scientifically. Studies in non-psychiatric populations show that reducing the nicotine content of cigarettes to non-addictive levels reduces smoking rates and nicotine dependence. However, few studies have examined this hypothesis in vulnerable populations.

METHODS

In this narrative review we examined the extant literature on the effects of nicotine reduction or cessation on symptoms of withdrawal, as well as psychiatric symptoms, among those with affective disorders.

RESULTS

Following initial withdrawal from nicotine, smokers with affective disorders experience more severe mood disruption than smokers without these disorders. Use of very low nicotine content (VLNC) cigarettes during abstinence may help mitigate the mood-disrupting effects of initial abstinence. Once the initial effects of nicotine withdrawal on mood have passed, longer-term abstinence is associated with psychiatric improvement rather than worsening.

CONCLUSIONS

These findings suggest that if a national nicotine reduction policy were to be implemented, smokers with affective disorders would need additional support to overcome initial withdrawal but that long-term outcomes would likely be positive.

Depressive symptoms affect changes in nicotine withdrawal and smoking urges throughout smoking cessation treatment: Preliminary results

BACKGROUND

Individuals who report more depressive symptoms consistently demonstrate higher rates of nicotine dependence and less successful smoking cessation than do individuals who report fewer depressive symptoms. Nicotine withdrawal and smoking urges are two potential factors that may account for the differences observed between these two groups. This study assessed whether elevated depression symptoms among nicotine dependent smokers are associated with changes in withdrawal and urges to smoke when undergoing smoking cessation treatment.

METHOD

Data on 81 nicotine dependent smokers were collected as part of a smoking cessation randomized trial that compared standard and contingency management treatment across one baseline week and four treatment weeks. Linear mixed model analyses were conducted with high and low depression scores predicting changes in withdrawal and urge ratings from a baseline week and four treatment weeks.

RESULTS

Participants with elevated depression symptoms reported more intense nicotine withdrawal and smoking urges throughout treatment. Further, participants with greater depressive symptoms exhibited an increase in smoking urges at the start of treatment, compared with a gradual decline in urges among participants with fewer depressive symptoms.

CONCLUSIONS

Smokers with elevated depressive symptoms experience significantly elevated discomfort during smoking cessation efforts in the form of increased withdrawal and craving. This discomfort has the potential to make quitting smoking more difficult. Clinical Trial Identifier: NCT00865254.

Effects of the BDNF Val66Met Polymorphism on Anxiety-Like Behavior Following Nicotine Withdrawal in Mice

INTRODUCTION

Nicotine withdrawal is characterized by both affective and cognitive symptoms. Identifying genetic polymorphisms that could affect the symptoms associated with nicotine withdrawal are important in predicting withdrawal sensitivity and identifying personalized cessation therapies. In the current study we used a mouse model of a non-synonymous single nucleotide polymorphism in the translated region of the brain-derived neurotrophic factor (BDNF) gene that substitutes a valine (Val) for a methionine (Met) amino acid (Val66Met) to examine the relationship between the Val66Met single nucleotide polymorphism and nicotine dependence.

METHODS

This study measured proBDNF and the BDNF prodomain levels following nicotine and nicotine withdrawal and examined a mouse model of a common polymorphism in this protein (BDNF(Met/Met)) in three behavioral paradigms: novelty-induced hypophagia, marble burying, and the open-field test.

RESULTS

Using the BDNF knock-in mouse containing the BDNF Val66Met polymorphism we found: (1) blunted anxiety-like behavior in BDNF(Met/Met) mice following withdrawal in three behavioral paradigms: novelty-induced hypophagia, marble burying, and the open-field test; (2) the anxiolytic effects of chronic nicotine are absent in BDNF(Met/Met) mice; and (3) an increase in BDNF prodomain in BDNF(Met/Met) mice following nicotine withdrawal.

CONCLUSIONS

Our study is the first to examine the effect of the BDNF Val66Met polymorphism on the affective symptoms of withdrawal from nicotine in mice. In these mice, a single-nucleotide polymorphism in the translated region of the BDNF gene can result in a blunted withdrawal, as measured by decreased anxiety-like behavior. The significant increase in the BDNF prodomain in BDNF(Met/Met) mice following nicotine cessation suggests a possible role of this ligand in the circuitry remodeling after withdrawal.

The influence of religious attendance on smoking

Generalized linear models were used to assess the relationship between religious attendance and lifetime smoking status among middle-aged adults (n = 666) sampled from waves three (1993 to 1996) and four (2004 to 2005) of the Baltimore Epidemiologic Catchment Area (ECA) study. Religious attendance once per week or greater as compared to never was inversely associated with smoking status. Future research should explore potential mediating factors of the association between religious attendance and smoking among middle-aged adults in order to gain a greater understanding of the mechanisms underlying this relationship.

FUNDING

NIMH grant DA026652; NIDA grant T32DA007292.

Effects of depressive symptoms on antecedents of lapses during a smoking cessation attempt: an ecological momentary assessment study

AIMS

To investigate pathways through which momentary negative affect and depressive symptoms affect risk of lapse during smoking cessation attempts.

DESIGN

Ecological momentary assessment was carried out during 2 weeks after an unassisted smoking cessation attempt. A 3-month follow-up measured smoking frequency.

SETTING

Data were collected via mobile devices in German-speaking Switzerland.

PARTICIPANTS

A total of 242 individuals (age 20-40, 67% men) reported 7112 observations.

MEASUREMENTS

Online surveys assessed baseline depressive symptoms and nicotine dependence. Real-time data on negative affect, physical withdrawal symptoms, urge to smoke, abstinence-related self-efficacy and lapses.

FINDINGS

A two-level structural equation model suggested that on the situational level, negative affect increased the urge to smoke and decreased self-efficacy (β = 0.20; β = -0.12, respectively), but had no direct effect on lapse risk. A higher urge to smoke (β = 0.09) and lower self-efficacy (β = -0.11) were confirmed as situational antecedents of lapses. Depressive symptoms at baseline were a strong predictor of a person's average negative affect (β = 0.35, all P < 0.001). However, the baseline characteristics influenced smoking frequency 3 months later only indirectly, through influences of average states on the number of lapses during the quit attempt.

CONCLUSIONS

Controlling for nicotine dependence, higher depressive symptoms at baseline were associated strongly with a worse longer-term outcome. Negative affect experienced during the quit attempt was the only pathway through which the baseline depressive symptoms were associated with a reduced self-efficacy and increased urges to smoke, all leading to the increased probability of lapses.

Chronic sazetidine-A maintains anxiolytic effects and slower weight gain following chronic nicotine without maintaining increased density of nicotinic receptors in rodent brain

Chronic nicotine administration increases the density of brain α4β2* nicotinic acetylcholine receptors (nAChRs), which may contribute to nicotine addiction by exacerbating withdrawal symptoms associated with smoking cessation. Varenicline, a smoking cessation drug, also increases these receptors in rodent brain. The maintenance of this increase by varenicline as well as nicotine replacement may contribute to the high rate of relapse during the first year after smoking cessation. Recently, we found that sazetidine-A (saz-A), a potent partial agonist that desensitizes α4β2* nAChRs, does not increase the density of these receptors in brain at doses that decrease nicotine self-administration, increase attention in rats, and produce anxiolytic effects in mice. Here, we investigated whether chronic saz-A and varenicline maintain the density of nAChRs after their up-regulation by nicotine. In addition, we examined the effects of these drugs on a measure of anxiety in mice and weight gain in rats. After increasing nAChRs in the rodent brain with chronic nicotine, replacing nicotine with chronic varenicline maintained the increased nAChR binding, as well as the α4β2 subunit proteins measured by western blots. In contrast, replacing nicotine treatments with chronic saz-A resulted in the return of the density of nAChRs to the levels seen in saline controls. Nicotine, saz-A and varenicline each demonstrated anxiolytic effects in mice, but only saz-A and nicotine attenuated the gain of weight over a 6-week period in rats. These findings suggest that apart from its modest anxiolytic and weight control effects, saz-A, or drugs like it, may be useful in achieving long-term abstinence from smoking.

The predicted impact of reducing the nicotine content in cigarettes on alcohol use

INTRODUCTION

Product standards reducing the level of nicotine in cigarettes could significantly improve public health by reducing smoking behavior and toxicant exposure. However, relatively little is known about how the regulatory strategy could impact alcohol use, a closely related health behavior that is also a major contributor to morbidity and mortality. The primary objective of this paper is to predict the effect of nicotine reduction on alcohol use, identify priorities for future research, and highlight areas for mitigating any adverse outcomes.

METHODS

We critically reviewed and integrated literatures examining the effects of very low nicotine content (VLNC) cigarettes on smoking-related outcomes (nicotine exposure, nicotine withdrawal, and smoking as a cue to drink) and, in turn, the effects of those outcomes on alcohol use.

RESULTS

Current evidence suggests reducing the nicotine content of cigarettes may benefit public health by reducing alcohol use and problematic drinking over time as a consequence of reduced exposure to nicotine and the smoking cues associated with drinking. Nicotine withdrawal could increase risk of drinking, although these effects should be short-lived and could be mitigated by other sources of nicotine. Gender, hazardous drinking, and psychiatric comorbidities are likely to be important moderators of the effects of VLNC cigarettes.

CONCLUSIONS

It is imperative to broadly assess the public health impact of potential tobacco product regulations by including measures of closely related health behaviors that could be impacted by these interventions. Nicotine reduction in cigarettes may contribute to improved public health through reductions in alcohol use.

Nicotine administration in adolescence reprograms the subsequent response to nicotine treatment and withdrawal in adulthood: sex-selective effects on cerebrocortical serotonergic function

Nicotine exposure in adolescence produces lasting changes in subsequent behavioral responses to addictive agents. We gave nicotine to adolescent rats (postnatal days PN30-47), simulating plasma levels in smokers, and then examined the subsequent effects of nicotine given again in adulthood (PN90-107), focusing on cerebrocortical serotonin levels and utilization (turnover) as an index of presynaptic activity of circuits involved in emotional state. Our evaluations encompassed responses during the period of adult nicotine treatment (PN105) and withdrawal (PN110, PN120, PN130), as well as long-term changes (PN180). In males, prior exposure to nicotine in adolescence greatly augmented the increase in serotonin turnover evoked by nicotine given in adulthood, an interaction that was further exacerbated during withdrawal. The effect was sufficiently large that it led to significant depletion of serotonin stores, an effect that was not seen with nicotine given alone in either adolescence or adulthood. In females, adolescent nicotine exposure blunted or delayed the spike in serotonin turnover evoked by withdrawal from adult nicotine treatment, a totally different effect from the interaction seen in males. Combined with earlier work showing persistent dysregulation of serotonin receptor expression and receptor coupling, the present results indicate that adolescent nicotine exposure reprograms future responses of 5HT systems to nicotine, changes that may contribute to life-long vulnerability to relapse and re-addiction.

Prospective Evaluation of Factors Predicting Nicotine Withdrawal Symptoms Among Korean Americans

INTRODUCTION

This study examined factors predicting nicotine withdrawal symptoms following quitting among Korean American smokers who were receiving counseling and nicotine replacement therapy.

METHODS

The sample comprised 90 Korean American smokers selected from a two-arm randomised controlled trial of a smoking cessation intervention (culturally adapted versus treatment as usual). Nicotine withdrawal symptoms were assessed weekly for the first four weeks from the target quit day, using the Minnesota Nicotine Withdrawal Scale (MNWS). Only those who participated in two or more weekly assessments of the symptoms were included.

RESULTS

Among the nine withdrawal symptoms listed in the MNWS, craving and disturbed sleep decreased over time whereas the remaining symptoms had no significant effect of time. Women or individuals who perceived greater risks of quitting smoking reported more withdrawal symptoms after controlling for abstinence status. Although withdrawal symptoms did not change, on average, with time, the rates of change varied randomly across individuals. Women reported more withdrawal symptoms in the first week after quitting and showed a higher rate of decline of the symptoms over time than men.

CONCLUSIONS

Korean American smokers who are women or who perceive greater risks of quitting smoking may require more intensive treatment to effectively deal with post-quit withdrawal symptoms.

Involvement of glutamatergic and GABAergic systems in nicotine dependence: Implications for novel pharmacotherapies for smoking cessation

Tobacco smoking continues to be a major global health hazard despite significant public awareness of its harmful consequences. Although several treatment options are currently available for smoking cessation, these medications are effective in only a small subset of smokers, and relapse rates continue to be high. Therefore, a better understanding of the neurobiological mechanisms that mediate tobacco dependence is essential for the development of effective smoking cessation medications. Nicotine is the primary psychoactive component of tobacco that drives the harmful tobacco smoking habit. Nicotine binds to nicotinic acetylcholine receptors (nAChRs) in the brain, resulting in the release of a wide range of neurotransmitters, including glutamate and γ-aminobutyric acid (GABA). This review article focuses on the role of the excitatory glutamate system and inhibitory GABA system in nicotine dependence. Accumulating evidence suggests that blockade of glutamatergic transmission or facilitation of GABAergic transmission attenuates the positive reinforcing and incentive motivational aspects of nicotine, inhibits the reward-enhancing and conditioned rewarding effects of nicotine, and blocks nicotine-seeking behavior. Chronic nicotine exposure produced long-term neuroadaptations that contribute to nicotine withdrawal, but the role of GABA and glutamate transmission in nicotine withdrawal is less understood. Overall, the findings presented in this review provide strong converging evidence for the potential effectiveness of glutamatergic and GABAergic medications in nicotine dependence. This article is part of a Special Issue entitled 'NIDA 40th Anniversary Issue'.

Divergent functional effects of sazetidine-a and varenicline during nicotine withdrawal

Smoking is the largest preventable cause of death in the United States. Furthermore, a recent study found that <10% of quit attempts resulted in continuous abstinence for 1 year. With the introduction of pharmacotherapies like Chantix (varenicline), a selective α4β2 nicotinic partial agonist, successful quit attempts have significantly increased. Therefore, novel subtype-specific nicotinic drugs, such as sazetidine-A, present a rich area for investigation of therapeutic potential in smoking cessation. The present studies examine the anxiety-related behavioral and functional effects of the nicotinic partial agonists varenicline and sazetidine-A during withdrawal from chronic nicotine in mice. Our studies indicate that ventral hippocampal-specific infusions of sazetidine-A, but not varenicline, are efficacious in reducing nicotine withdrawal-related anxiety-like phenotypes in the novelty-induced hypophagia (NIH) paradigm. To further investigate functional differences between these partial agonists, we utilized voltage-sensitive dye imaging (VSDi) in ventral hippocampal slices to determine the effects of sazetidine-A and varenicline in animals chronically treated with saline, nicotine, or undergoing 24 h withdrawal. These studies demonstrate a functional dissociation of varenicline and sazetidine-A on hippocampal network activity, which is directly related to previous drug exposure. Furthermore, the effects of the nicotinic partial agonists in VSDi assays are significantly correlated with their behavioral effects in the NIH test. These findings highlight the importance of drug history in understanding the mechanisms through which nicotinic compounds may be aiding smoking cessation in individuals experiencing withdrawal-associated anxiety.

A systematic review of the relationships between craving and smoking cessation

INTRODUCTION

Craving is often portrayed as a defining feature of addiction, but the role of craving in the addictive process is controversial. Particularly contentious is the extent to which drug craving predicts subsequent relapse.

METHODS

This review synthesizes findings from 62 smoking cessation studies published through December 2011. Eligible studies measured craving for cigarettes in treatment-seeking smokers and related this to subsequent smoking status. The relationships of general craving and cue-specific craving with treatment outcome were examined separately. Further, analyses that related general craving to smoking status were divided into those that used craving data collected before the quit attempt, after the quit attempt, and those that used change in craving over time as a predictor.

RESULTS

Results across studies revealed a total of 198 indices of association with 94 (47%) of these being significant. In general, the findings indicated (a) there were only a few cases of significant associations between craving collected as part of cue-reactivity studies and treatment outcome, (b) postquit craving was a stronger predictor of treatment outcome than prequit craving, and (c) several moderators likely influence the relationship between craving and cessation outcome.

CONCLUSIONS

The overall results suggest that craving is not a necessary condition of relapse. In addition, inconsistent relationships between craving and treatment outcome call into question the value of craving as a target of treatment and underscore limitations in the prognostic utility of craving.

Two decades of smoking cessation treatment research on smokers with depression: 1990-2010

INTRODUCTION

Adults with depression smoke at higher rates than other adults leaving a large segment of this population, who already incur increased health-related risks, vulnerable to the enormous harmful consequences of smoking. Yet, the impact that depression has on smoking cessation is not clear due to the mixed results of past research. The primary aims of this review were to synthesize the research examining the relationship of depression to smoking cessation outcomes over a 20-year period, to examine the gender and racial composition of these studies, and to identify directions for future research.

METHODS

Potential articles published between January 1, 1990 and December 31, 2010 were identified through a MEDLINE search of the terms "clinical trial," "depression," and "smoking cessation." 68 studies used all three terms and met the inclusion criteria.

RESULTS

The majority of studies examined either a past diagnosis of major depression or current depression symptoms. Within the few studies that examined the interaction of gender and depression on smoking cessation, depression had a greater impact on treatment outcomes for women than men. No study reported examining the interactive impact of race and depression on treatment outcomes.

CONCLUSIONS

Although attention to the relationship of depression and smoking cessation outcomes has increased over the past 20 years, little information exists to inform a treatment approach for smokers with Current Major Depressive Disorder, Dysthymia, and Minor Depression and few studies report gender and racial differences in the relationship of depression and smoking cessation outcomes, thus suggesting major areas for targeted research.

Depressive symptoms among heavy cigarette smokers: the influence of daily rate, gender, and race

INTRODUCTION

Cigarette smokers experience higher levels of depressive symptoms and are more likely to be diagnosed with depressive disorders than nonsmokers. To date, the nature of the smoking-depression relationship has not been adequately studied among heavy smokers, a group at elevated risk for poor health outcomes. In this study, we examined depressive symptom expression among heavy smokers while considering the moderating roles of smoking status, gender, and race. We also explored whether amount of tobacco usually consumed had an impact.

METHODS

We extracted data from a large, highly nicotine-dependent, nontreatment cigarette smoking study sample (N = 6,158). Participants who consented were screened for major exclusions, and they completed questionnaires.

RESULTS

Smokers reported a higher, clinically meaningful level of depressive symptoms relative to nonsmokers (27.3% of smokers vs. 12.5% of nonsmokers) scored above the clinical cutoff on the Center for Epidemiological Studies Depression (CES-D) scale (p < .001), which differed among race × gender subgroups. Further, amount of daily intake was inversely associated with self-report of depressive symptoms. For every 10-cigarette increment, the likelihood of scoring above the CES-D clinical cutoff decreased by 62% (p < .0001).

CONCLUSIONS

These findings improve our understanding of tobacco's influence on depressive symptom expression among heavy smokers, with implications for tailoring evidence-based tobacco treatments.

Sex-specific differences in GABA(A) -benzodiazepine receptor availability: relationship with sensitivity to pain and tobacco smoking craving

Sex differences exist in tobacco smoking behaviors. Nicotine, the primary addictive ingredient in tobacco smoke, indirectly affects γ-amino butyric acid (GABA) function. Previous studies reported sex-by-smoking interactions in brain GABA levels. The goal of the present study was to evaluate if there is a sex-by-smoking interaction at the GABA(A)-benzodiazepine receptors (GABA(A)-BZRs), as well as relationships between GABA(A)-BZR availability and behavioral variables before and after 1 week of smoking cessation. Twenty-six women (8 non-smokers, age 36.0 ± 13.4 years; 19 smokers, age 34.6 ± 8.9 years) and 25 men (8 non-smokers, age 37.9 ± 13.8 years; 17 smokers, 34.1 ± 12.4 years) were imaged using [123I]iomazenil and single-photon emission computed tomography. Smokers were imaged at baseline 7 hours after the last cigarette. A significantly great number of men were able to abstain from smoking for 1 week (P = 0.003). There were no significant differences in nicotine dependence and cigarette craving, mood or pain sensitivity between male and female smokers. There was a significant effect of gender across all brain regions (frontal, parietal, anterior cingulate, temporal and occipital cortices, and cerebellum; P < 0.05), with all women (smokers and non-smokers combined) having a higher GABA(A)-BZR availability than all men. There was a negative correlation between GABA(A)-BZR availability and craving (P ≤ 0.02) and pain sensitivity (P = 0.04) in female smokers but not male smokers. This study provides further evidence of a sex-specific regulation of GABA(A)-BZR availability in humans and demonstrates the potential for GABA(A)-BZRs to mediate tobacco smoking craving and pain symptoms differentially in female and male smokers.

The relationship of dysthymia, minor depression, and gender to changes in smoking for current and former smokers: longitudinal evaluation in the U.S. population

BACKGROUND

Although data clearly link major depression and smoking, little is known about the association between dysthymia and minor depression and smoking behavior. The current study examined changes in smoking over 3 years for current and former smokers with and without dysthymia and minor depression.

METHODS

Participants who were current or former daily cigarette smokers at Wave 1 of the National Epidemiologic Survey on Alcohol and Related Conditions and completed the Wave 2 assessment were included in these analyses (n=11,973; 46% female). Analyses examined the main and gender-specific effects of current dysthymia, lifetime dysthymia, and minor depression (a single diagnostic category that denoted current and/or lifetime prevalence) on continued smoking for Wave 1 current daily smokers and continued abstinence for Wave 1 former daily smokers.

RESULTS

Wave 1 current daily smokers with current dysthymia (OR=2.13, 95% CI=1.23, 3.70) or minor depression (OR=1.53, 95% CI=1.07, 2.18) were more likely than smokers without the respective diagnosis to report continued smoking at Wave 2. Wave 1 former daily smokers with current dysthymia (OR=0.44, 95% CI=0.20, 0.96) and lifetime dysthymia (OR=0.37, 95% CI=0.15, 0.91) were less likely than those without the diagnosis to remain abstinent from smoking at Wave 2. The gender-by-diagnosis interactions were not significant, suggesting that the impact of dysthymia and minor depression on smoking behavior is similar among men and women.

CONCLUSIONS

Current dysthymia and minor depression are associated with a greater likelihood of continued smoking; current and lifetime dysthymia are associated with a decreased likelihood of continued smoking abstinence.

Symptoms of depression and smoking behaviors following treatment with transdermal nicotine patch

Subscales from the Center for Epidemiologic Studies depression scale (CESD), assessed prior to treatment, were examined as predictors of withdrawal, craving, and affect during the first week of abstinence, as well as smoking abstinence during the first week of abstinence and at the end of treatment. The negative affect and somatic features CESD subscales were related to higher levels of nicotine withdrawal. The relationship between the interpersonal disturbance CESD subscale and nicotine withdrawal approached significance. This study suggests the need to examine novel psychological mechanisms that may account for the relationship between depression symptoms and smoking cessation.

Effects of nicotine dependence and depressive symptoms on smoking cessation: a longitudinal study among adolescents

INTRODUCTION

Nicotine dependence has been shown to hamper successful smoking cessation in adolescents. Nicotine dependence and depression are highly comorbid, but the relation between depression and smoking cessation is not yet fully understood. Therefore, the present study examines both the longitudinal reciprocal relation between nicotine dependence and depressive symptoms, and the longitudinal effect of these factors on successful smoking cessation and number of quit attempts.

METHODS

A 2-wave longitudinal study was conducted among 535 adolescents aged 13-18. Written self-report questionnaires were administered in a classroom setting. Two models were tested, examining the mutual relation between nicotine dependence and depressive symptoms, as well as the predictive value of these factors on smoking cessation (n = 535), and number of quit attempts (n = 473) 1 year later.

RESULTS

Adolescents with more depressive symptoms have significantly higher levels of nicotine dependence 1 year later. Higher levels of nicotine dependence negatively predicted subsequent successful smoking cessation, whereas depressive symptoms did not. In contrast, depressive symptoms predicted a higher number of unsuccessful quit attempts in the following year, whereas nicotine dependence did not.

CONCLUSIONS

The findings suggest that adolescents tend to smoke cigarettes in order to diminish their depressive feelings, which might provide some support for the self-medication theory. Smoking cessation programs aiming at adolescents should not only focus on symptoms of nicotine dependence but should also pay attention to depressive feelings, since these feelings are related to a higher number of unsuccessful quit attempts.

The relationship of major depressive disorder and gender to changes in smoking for current and former smokers: longitudinal evaluation in the US population

AIMS

Although depression and smoking are correlated highly, the relationship of major depressive disorder (MDD) to smoking cessation and relapse remains unclear. This study compared changes in smoking for current and former smokers with and without current and life-time MDD over a 3-year period.

DESIGN

Analysis of two waves of longitudinal data from the National Institute on Alcohol Abuse and Alcoholism's National Epidemiologic Survey on Alcohol and Related Conditions (wave 1, 2001-02; wave 2, 2004-05).

SETTING

Data were collected through face-to-face interviews from non-institutionalized United States civilians, aged 18 years and older, in 50 states and the District of Columbia.

PARTICIPANTS

A total of 11 973 adults (54% male) classified as current or former daily smokers at wave 1 and completed wave 2.

MEASUREMENTS

Classification as current or former smokers at wave 1 and wave 2.

FINDINGS

Smoking status remained stable for most participants. Wave 1 current daily smokers with current MDD [odds ratio (OR) = 1.38, 95% confidence interval (CI): 1.03, 1.85] and life-time MDD (OR = 1.52, 95% CI: 1.15, 2.01) were more likely than those without the respective diagnosis to report continued smoking at wave 2. Wave 1 former daily smokers with current MDD (OR = 0.44, 95% CI: 0.26, 0.76) were less likely to report continued abstinence at wave 2. None of the gender × MDD diagnosis interactions were significant. Patterns of results remained similar when analyses were limited to smokers with nicotine dependence.

CONCLUSIONS

Current and life-time major depressive disorders are associated with a lower likelihood of quitting smoking and current major depressive disorder is associated with greater likelihood of smoking relapse.

Serotonin involvement in Rhodiola rosea attenuation of nicotine withdrawal signs in rats

Rhodiola rosea has been used for centuries in the traditional medicine to stimulate nervous system, to enhance physical and mental performance and to treat fatigue. It is known that administration of Rhodiola rosea extract elicits antidepressant activity, but the mechanism of action still remains unclear. Evidence from animal models and human studies show that nicotine reduces symptoms of depression and that nicotine cessation induces depressive-like symptoms. We investigated the effects of Rhodiola rosea on nicotine withdrawal signs. Nicotine dependence was induced by subcutaneous nicotine injection (2 mg/kg, four times daily) for 14 days. Another group of animals treated with nicotine (for 14 days) and successively with Rhodiola rosea extract was co-administered with selective 5-HT receptorial antagonist WAY 100635 (1 mg/kg). After nicotine withdrawal animals were evaluated for behavioural parameters (locomotor activity, abstinence signs, marble burying test), diencephalic serotonin metabolism and serotonin receptor-1A expression. Results show a significant increase of 5-HT content in N treated with R. rosea, with a significant increase of serotonin receptor 1A, suggesting an involvement of serotonin in beneficial effects of R. rosea on suffering produced by nicotine withdrawal.

Smoking cue reactivity in adult smokers with and without depression: a pilot study

Little is known about the relationship between Major Depressive Disorder (MDD) and smoking-related behaviors such as cue-induced urges to smoke. The purpose of this pilot study was to examine: (1) differences in smoking cue reactivity by MDD history and (2) the association of a diagnosis of MDD, current depressive symptoms, and smoking variables to cue-induced urges to smoke. Participants (N = 52) were n = 31 smokers with no MDD history and n = 21 smokers with past MDD. Participants completed a 2-hour laboratory session during which they were exposed to neutral (eg, pencils) and smoking cues (eg, cigarettes) after smoking one of their preferred brand cigarettes (Satiated Condition) and when it had been 1 hour since they smoked (Brief Deprivation Condition). Cue-induced urges increased with exposure to smoking cues and this increase did not significantly differ by diagnosis group. Current symptoms of depression, but not a diagnosis of MDD, were significantly and positively related to cue-induced cravings in satiated adult smokers. The association between depression symptoms and smoking urges was not significant in the Brief Deprivation Condition. Smoking cue reactivity may be a useful procedure for studying aspects of smoking behavior in adults with depression.

Predictors of risk for smoking relapse in men and women: a prospective examination

The current study examined whether prequit trait negative mood and smoking motives have different predictive patterns of smoking relapse in men and women. Thirty-three female (mean age±SEM: 34.9±2.5) and 38 male (mean age±SEM: 37.1±2.3) smokers interested in smoking cessation completed forms on smoking history, negative mood (i.e., depression, anxiety, and anger), stress, and smoking motives. Participants also provided samples for measurement of cotinine and carbon monoxide. Then, they set a quit date and were required to abstain from smoking at least for 24 hours. Participants were followed up for 12 months postcessation to measure their smoking status. Cox proportional hazard models revealed that motivation to reduce craving was a unique predictor of smoking relapse in men, while depressive mood, anxiety, anger, and perceived stress were predictive of time to relapse among women. These findings remained significant after statistically controlling for smoking-related variables, providing preliminary evidence that different factors may be associated with nicotine withdrawal and smoking relapse in men and women.