12h abstinence-induced right anterior insula network pattern changes in young smokers

Stress and substance use disorders: risk, relapse, and treatment outcomes

Stress has long been associated with substance misuse and substance use disorders (SUDs). The past two decades have seen a surge in research aimed at understanding the underlying mechanisms driving this association. This Review introduces a multilevel "adaptive stress response" framework, encompassing a stress baseline, acute reaction, and recovery with return-to-homeostasis phase that occurs at varying response times and across domains of analysis. It also discusses evidence showing the disruption of this adaptive stress response in the context of chronic and repeated stressors, trauma, adverse social and drug-related environments, as well as with acute and chronic drug misuse and with drug withdrawal and abstinence sequelae. Subjective, cognitive, peripheral, and neurobiological disruptions in the adaptive stress response phases and their link to inflexible, maladaptive coping; increased craving; relapse risk; and maintenance of drug intake are also presented. Finally, the prevention and treatment implications of targeting this "stress pathophysiology of addiction" are discussed, along with specific aspects that may be targeted in intervention development to rescue stress-related alterations in drug motivation and to improve SUD treatment outcomes.

Craving dynamics and related cerebral substrates predict timing of use in alcohol, tobacco, and cannabis use disorders

Background

Patients treated for Substance Use Disorders exhibit highly fluctuating patterns of craving that could reveal novel prognostic markers of use. Accordingly, we 1) measured fluctuations within intensively repeated measures of craving and 2) linked fluctuations of craving to connectivity indices within resting-state (rs) brain regions to assess their relation to use among patients undergoing treatment for Alcohol, Tobacco and Cannabis Use Disorders.

Method

Participants -64 individuals with SUD for tobacco, alcohol, or cannabis and 35 healthy controls-completed a week of Ecological Momentary Assessment (EMA) during which they reported craving intensity and substance use five times daily. Before EMA, a subsample of 50 patients, and 34 healthy controls also completed resting-state (rs)-MRI acquisitions. Craving temporal dynamics within each day were characterized using Standard Deviation (SD), Auto-Correlation Factor (ACF), and Mean Successive Square Difference (MSSD). Absolute Difference (AD) in craving between assessments was a prospective prediction measure.

Results

Within-day, higher MSSD predicted greater substance use while controlling for mean craving. Prospectively higher AD predicted later increased substance use independently of previous use or craving level. Moreover, MSSD was linked to strength in five functional neural connections, most involving frontotemporal systems. Cerebello-thalamic and thalamo-frontal connectivity were also linked to substance use and distinguished the SUD from the controls.

Conclusion

To the best of our knowledge, this is the first study to indicate that instability in craving may be a trigger for use in several SUD types, beyond the known effect of craving intensity.

The changes of intrinsic connectivity contrast in young smokers

Previous studies demonstrated that reward circuit plays an important role in smoking. The differences of functional and structural connectivity were found among several brain regions such as thalamus and frontal lobe. However, few studies focused on functional connectivity (FC) in whole-brain voxel level of young smokers. In this study, intrinsic connectivity contrast (ICC) was used to perform voxel-based whole-brain analyses in 55 young smokers and 55 matched non-smokers to identify brain regions with significant group differences. ICC results showed that the connectivity of young smokers in medial frontal cortex (MedFC), supramarginal gyrus anterior division left (L_aSMG), central opercular cortex left (L_CO) and middle frontal gyrus left (L_MidFG) showed a significantly lower trend compared with the non-smokers. The seed-based FC analysis about MedFC indicated that young smokers showed reduced connectivity between the MedFC and left hippocampus, left amygdala compared to non-smokers. Correlation analysis showed that the ICC of MedFC in young smokers was significantly negatively correlated with Fagerstrom test for nicotine dependence (FTND) and Questionnaire on Smoking Urges (QSU). The FC between the MedFC and left hippocampus, left amygdala was significantly negatively correlated with Pack_years. The mediation analysis indicated that ICC of MedFC completely mediated FTND and QSU of young smokers. The results suggest that nicotine accumulation may affect the communication of the frontal lobe with the whole brain to some extent, leading to changes in smoking cravings. The above research also provides in-depth insights into the mechanism of adolescent smoking addiction and related intervention treatment.

An orbitofrontal cortex-anterior insular cortex circuit gates compulsive cocaine use

Compulsive drug use, a cardinal symptom of drug addiction, is characterized by persistent substance use despite adverse consequences. However, little is known about the neural circuit mechanisms behind this behavior. Using a footshock-punished cocaine self-administration procedure, we found individual variability of rats in the process of drug addiction, and rats with compulsive cocaine use presented increased neural activity of the anterior insular cortex (aIC) compared with noncompulsive rats. Chemogenetic manipulating activity of aIC neurons, especially aIC glutamatergic neurons, bidirectionally regulated compulsive cocaine intake. Furthermore, the aIC received inputs from the orbitofrontal cortex (OFC), and the OFC-aIC circuit was enhanced in rats with compulsive cocaine use. Suppression of the OFC-aIC circuit switched rats from punishment resistance to sensitivity, while potentiation of this circuit increased compulsive cocaine use. In conclusion, our results found that aIC glutamatergic neurons and the OFC-aIC circuit gated the shift from controlled to compulsive cocaine use, which could serve as potential therapeutic targets for drug addiction.

Effects of Smoking Status and State on Intrinsic Connectivity

BACKGROUND

Smoking behavior during the first 24 hours of a quit attempt is a significant predictor of longer-term abstinence, yet little is known about the neurobiology of early tobacco abstinence. Specifically, the effects of acute tobacco deprivation and reinstatement on brain function-particularly at the level of large-scale network dynamics and assessed across the entire brain-remain incompletely understood. To address this gap, this study used a mixed within- and between-subjects design to assess the effects of smoking status (yes/no smoker) and state (deprived vs. satiated) on whole-brain patterns of intrinsic connectivity.

METHODS

Participants included 42 tobacco smokers who underwent resting-state functional magnetic resonance imaging following overnight abstinence (deprived state) and following smoking reinstatement (satiated state, randomized order across participants). Sixty healthy control nonsmokers underwent a single resting-state scan using the same acquisition parameters. Functional connectivity data were analyzed using both a canonical network-of-interest approach and a whole-brain, data-driven approach, i.e., intrinsic connectivity distribution.

RESULTS

Network-of-interest-based analyses indicated decreased functional connectivity within frontoparietal and salience networks among smokers relative to nonsmokers as well as effects of smoking state on default mode connectivity. In addition, intrinsic connectivity distribution analyses identified novel between-group differences in subcortical-cerebellar and corticocerebellar networks that were largely smoking state dependent.

CONCLUSIONS

These data demonstrate the importance of considering smoking state and the utility of using both theory- and data-driven analysis approaches. These data provide much-needed insight into the functional neurobiology of early abstinence, which may be used in the development of novel treatments.

Magnetic resonance imaging for smoking abstinence: symptoms, mechanisms, and interventions

Tobacco smoking is the leading preventable cause of morbidity and mortality worldwide. Although a number of smokers are aware of the adverse outcomes of smoking and express a strong desire to stop smoking, most smoking quit attempts end in relapse within the first few days of abstinence, primarily resulting from the aversive aspects of the nicotine withdrawal syndrome. Therefore, studying the neural mechanisms of smoking abstinence, identifying smokers with heightened relapse vulnerability prior to quit attempts, and developing effective smoking cessation treatments appear to be promising strategies for improving the success of quit attempts. In recent years, with the development of magnetic resonance imaging, the neural substrates of smoking abstinence have become extensively studied. In this review, we first introduce the psychophysiological changes induced by smoking abstinence, including affective, cognitive, and somatic signs. We then provide an overview of the magnetic resonance imaging-based evidence regarding abstinence-related functional changes accompanied by these psychophysiological changes. We conclude with a discussion of the neural markers that could predict relapse during quit attempts and a summary of the psychophysiological interventions that are currently often used to help with smoking cessation. This review extends our understanding of the role of the central nervous system in smoking abstinence.

The changes of brain functional networks in young adult smokers based on independent component analysis

Intrinsic functional connectivity (FC) networks, including the default mode network (DMN), central executive network (CEN), and salience network (SN), have been implicated in nicotine addiction. However, litter evidence exists about the abnormalities in the three networks in young adult smokers. Forty-eight young adult smokers and 49 age- and gender-matched non-smokers were recruited in the present study. Resting-state functional magnetic resonance imaging (fMRI) data were analyzed by a combination of independent component analysis (ICA) and dual regression to identify potential differences of FC patterns in the DMN, CEN, and SN. Compared to non-smokers, young adult smokers showed enhanced FC of the left posterior cingulate cortex (LPCC), right medial prefrontal cortex (RMPFC) and right precuneus within the DMN network, of the right dorsolateral prefrontal cortex (DLPFC) within the right CEN, and of the left anterior insula (LAI) within the SN. We also found increased FC between the DMN, CEN and key node of the SN (anterior insula, AI). Correlation analysis showed that the increased FC within the networks was significantly correlated with smoking behaviors (pack-years, smoking duration, FTND, first smoking age, and number of cigarettes per day). Our findings may provide additional evidence for conceptualizing the framework of nicotine addiction as a disease of intercommunicating brain networks.

Test-retest reliability of laser evoked pain perception and fMRI BOLD responses

Pain perception is a subjective experience and highly variable across time. Brain responses evoked by nociceptive stimuli are highly associated with pain perception and also showed considerable variability. To date, the test–retest reliability of laser-evoked pain perception and its associated brain responses across sessions remain unclear. Here, an experiment with a within-subject repeated-measures design was performed in 22 healthy volunteers. Radiant-heat laser stimuli were delivered on subjects’ left-hand dorsum in two sessions separated by 1–5 days. We observed that laser-evoked pain perception was significantly declined across sessions, coupled with decreased brain responses in the bilateral primary somatosensory cortex (S1), right primary motor cortex, supplementary motor area, and middle cingulate cortex. Intraclass correlation coefficients between the two sessions showed “fair” to “moderate” test–retest reliability for pain perception and brain responses. Additionally, we observed lower resting-state brain activity in the right S1 and lower resting-state functional connectivity between right S1 and dorsolateral prefrontal cortex in the second session than the first session. Altogether, being possibly influenced by changes of baseline mental state, laser-evoked pain perception and brain responses showed considerable across-session variability. This phenomenon should be considered when designing experiments for laboratory studies and evaluating pain abnormalities in clinical practice.

Supraspinal neural mechanisms of the analgesic effect produced by transcutaneous electrical nerve stimulation

Although the analgesic effects of conventional transcutaneous electrical nerve stimulation (TENS) and acupuncture-like TENS are evident, their respective neural mechanisms in humans remain controversial. To elucidate and compare the supraspinal neural mechanisms of the analgesic effects produced by conventional TENS (high frequency and low intensity) and acupuncture-like TENS (low frequency and high intensity), we employed a between-subject sham-controlled experimental design with conventional, acupuncture-like, and sham TENS in 60 healthy human volunteers. In addition to assessing the TENS-induced changes of subjective ratings of perceived pain, we examined the TENS associated brainstem activities (fractional amplitude of low frequency fluctuations, fALFF) and their corresponding resting state functional connectivity (RSFC) with higher-order brain areas using functional magnetic resonance imaging. The analgesic effect of conventional TENS was only detected in the forearm that received TENS, coupled with decreased pons activity and RSFC between pons and contralateral primary somatosensory cortex. In contrast, acupuncture-like TENS produced a spatially diffuse analgesic effect, coupled with increased activities in both subnucleus reticularis dorsalis (SRD) and rostral ventromedial medulla (RVM), and decreased RSFC between SRD and medial frontal regions as well as between SRD and lingual gyrus. To sum up, our data demonstrated that conventional TENS and acupuncture-like TENS have different analgesic effects, which are mediated by different supraspinal neural mechanisms.

Abnormal white matter tracts of insula in smokers

Nicotine addiction is characterized as a neural circuit dysfunction, particularly with regard to the alterations in central reward pathways. The insula, a cortical region that is thought to play a central role in this reward circuitry, has been implicated in the maintenance of nicotine addiction. However, it remains largely unclear about the white matter (WM) microstructural alterations of insula in nicotine addiction and whether the WM alterations of insula could predict smoking cessation outcomes. In this study, 58 male nicotine-dependent smokers and 34 matched male nonsmoking controls were recruited. After a 12-week smoking cessation treatment with varenicline, 38 smokers relapsed, and 20 did not relapse. Diffusion tensor imaging and probabilistic tractography were used to investigate the differences of WM tracts of insula between smokers and nonsmokers. Relative to nonsmokers, in the left hemisphere, smokers showed lower fractional anisotropy (FA) in the fiber tracts of anterior insula cortex-to-nucleus accumbens and posterior insula cortex-to-nucleus accumbens; in the right hemisphere, smokers showed higher FA, and lower axial diffusivity (AD), radial diffusivity (RD), and mean diffusivity (MD) in the fiber tracts of anterior insula cortex-to-medial orbitofrontal cortex, posterior insula cortex-to-medial orbitofrontal cortex, and posterior insula cortex-to-nucleus accumbens. However, there were no differences of WM diffusion properties between relapsers and nonrelapsers. This study is the first using probabilistic tractography to exclusively clarify the precise roles of insular WM tracts in smokers, which may provide new insights into the underlying neurobiology of nicotine addiction.

Altered neural processing of negative stimuli in people with internet gaming disorder: fMRI evidence from the comparison with recreational game users

BACKGROUND

Abundant clinical studies have suggested that emotion dysregulation seems to be the essential pathogenesis for Internet gaming disorder (IGD). However, the neural mechanism of emotion regulation for IGD is still unclear.

METHODS

Subjective evaluation and fMRI data were collected from 50 subjects (IGD: 24; recreational game user (RGU): 26) while they were performing an emotion reappraisal task. We collected and compared their brain features during emotion processing of different visual stimuli.

RESULTS

Higher activation in the left dorsal anterior cingulate cortex (dACC), right ventral ACC, left claustrum and bilateral insula was observed in participants with IGD during emotion reappraisal relative to that of the RGU participants. In addition, generalized psychophysiological interaction analysis also showed that IGD participants had stronger functional connectivity between the right insula and bilateral dorsolateral prefrontal cortex (DLPFC) than the RGU participants.

CONCLUSIONS

The results suggest that IGD participants could not down-regulate their negative emotional experiences as efficiently as the RGU participants, although they engaged more cognitive resources. These results reveal the special neural circuits of emotion dysregulation in IGD individuals and provide new neural perspective for the intervention of IGD.

12-h abstinence-induced functional connectivity density changes and craving in young smokers: a resting-state study

Studying the neural correlates of craving to smoke is of great importance to improve treatment outcomes in smoking addiction. According to previous studies, the critical roles of striatum and frontal brain regions had been revealed in addiction. However, few studies focused on the hub of brain regions in the 12 h abstinence induced craving in young smokers. Thirty-one young male smokers were enrolled in the present study. A within-subject experiment design was carried out to compare functional connectivity density between 12-h smoking abstinence and smoking satiety conditions during resting state in young adult smokers by using functional connectivity density mapping (FCDM). Then, the functional connectivity density changes during smoking abstinence versus satiety were further used to examine correlations with abstinence-induced changes in subjective craving. We found young adult smokers in abstinence state (vs satiety) had higher local functional connectivity density (lFCD) and global functional connectivity density (gFCD) in brain regions including striatal subregions (i.e., bilateral caudate and putamen), frontal regions (i.e., anterior cingulate cortex (ACC) and orbital frontal cortex (OFC)) and bilateral insula. We also found higher lFCD during smoking abstinence (vs satiety) in bilateral thalamus. Additionally, the lFCD changes of the left ACC, bilateral caudate and right OFC were positively correlated with the changes in craving induced by abstinence (i.e., abstinence minus satiety) in young adult smokers. The present findings improve the understanding of the effects of acute smoking abstinence on the hubs of brain gray matter in the abstinence-induces craving and may contribute new insights into the neural mechanism of abstinence-induced craving in young smokers in smoking addiction.

Electrophysiological Evidence of Event-Related Potential Changes Induced by 12 h Abstinence in Young Smokers Based on the Flanker Study

The cognitive control processes may be disrupted by abstinence in smokers, which may be helpful in the development and maintenance of addictive behavior. The purpose of this study was to measure the performance of cognitive task after 12 h of smoking abstinence by using event-related potentials (ERPs), including the error-related negativity (ERN) and the error positivity (Pe). In Eriksen flanker task, electroencephalography (EEG) signals of 24 smokers were recorded in two conditions: satiety and 12 h abstinence. In the behavioral data, both conditions exhibited more errors and more time on the incongruent trials than congruence. Meantime, the Minnesota Nicotine Withdrawal Scale (MNWS) score was increased during abstinence. Smokers showed reduced ERN and Pe after 12 h of abstinence, compared with satiety condition. The results indicate that the diminished error processing in young smokers after 12 h of abstinence. It may be related to increased withdrawal symptoms. In conclusion, the disrupted neurophysiological indexes in the general behavior monitoring system may be caused by abstinence. The results of this study may provide us with new ideas about the effects of short-term abstinence on brain cognitive neuroscience and be helpful for the solution of relapse.

Neural basis of smoking-induced relief of craving and negative affect: Contribution of nicotine

Smoking-induced relief of craving and withdrawal promotes continued cigarette use. Understanding how relief is produced and the role of nicotine in this process may facilitate development of new smoking-cessation therapies. As the US Food and Drug Administration considers setting a standard for reduced nicotine content in cigarettes to improve public health, knowledge of how nicotine contributes to relief also can inform policy. We assessed effects of nicotine using resting state functional magnetic resonance imaging (MRI) and behavioral assessments of craving and negative affect. Twenty-one young (18-25 years old) daily smokers underwent overnight abstinence on 4 days. On each of the following mornings, they self-rated their cigarette craving and negative affect and underwent resting-state functional MRI (fMRI) before and after smoking a cigarette that delivered 0.027, 0.110, 0.231, or 0.763 mg of nicotine. Functional connectivity between the anterior insula and anterior cingulate cortex (ACC) and between the nucleus accumbens and orbitofrontal cortex (OFC) was assessed. Smoking reduced craving, negative affect, and nucleus accumbens-OFC connectivity irrespective of nicotine dose, with positive correlations of the effects on behavioral and connectivity measures. Only the highest nicotine dose (0.763 mg) reduced right anterior insula-ACC connectivity; this reduction was positively correlated with the behavioral effects of the 0.763-mg dose only. While nicotine-based therapies may act on right anterior insula-ACC functional circuits to facilitate smoking cessation, non-nicotine (eg, the conditioned and sensorimotor) aspects of smoking may promote cessation by reducing OFC-accumbens connectivity to alleviate withdrawal.

12 h Abstinence-Induced ERP Changes in Young Smokers: Electrophysiological Evidence From a Go/NoGo Study

Decreased inhibition control ability and increased craving may be the most important causes of relapsing in smoking. Although inhibition control defects in young smokers were investigated, the effects of short-term abstinence on inhibition control in young smokers were still unclear. Thirty young smokers participated in the present study. The EEG signals during the Go/NoGo task were recorded in both satiety and 12 h abstinence conditions. The task performances were observed and compared between the two conditions. Event-related potential (ERP) analysis was used to investigate changes in N200 and P300 amplitude and latency induced by 12 h of abstinence. After 12 h of abstinence, the latency of N200 was prolonged in young smokers. No significant changes were found in the number of NoGo errors and the response time of Go in young smokers after 12 h of abstinence. Correlation analysis showed that the N200 latency of abstinence condition was significantly correlated with the number of NoGo errors and the response time of Go in the abstinence condition. The present findings may improve the understanding of the effect of short-term abstinence in young smokers. We suggested that the latency of N200 may be associated with inefficient inhibitory control of the abstinence condition in young smokers. Our results may contribute new insights into the neural mechanism of nicotine abstinence in young smokers.

Region-Specific Changes of Insular Cortical Thickness in Heavy Smokers

Insula plays an essential role in maintaining the addiction to cigarette smoking and smoking-related alterations on the insular volume and density have been reported in smokers. However, less is known about the effects of chronic cigarette smoking on the insular cortical thickness. In this study, we explored the region-specific changes of insular cortical thickness in heavy smokers and their relations with smoking-related variables. 37 heavy smokers (29 males, mean age 47.19 ± 7.22 years) and 37 non-smoking healthy controls (29 males, mean age 46.95 ± 8.45 years) participated in the study. Subregional insular cortical thickness was evaluated and compared between the two groups. Correlation analysis was performed to investigate relationships between the insular cortical thickness and clinical characteristics in heavy smokers. There was no statistical difference on the cortical thickness in the left insula (p = 0.536) between the two groups while heavy smokers had a slightly thinner cortical thickness in the right insula (p = 0.048). In addition, heavy smokers showed a greater cortical thinning in the anterior (p = 0.0084) and superior (p = 0.0054) segment of the circular sulcus of the right insula as well as the inferior (p = 0.012) segment of the circular sulcus of the left insula. Moreover, the cortical thickness of the superior segment of the circular sulcus of the left insula was correlated negatively with nicotine severity (r = −0.423; p = 0.009) and the longer cigarette exposure was associated with the cortical thinning in the long insular gyrus and central sulcus of the right insula (r = −0.475; p = 0.003). Our findings indicate that chronic cigarette use is associated with region-specific insular thinning, which has the potential to improve our understanding of the specific roles of insular subregions in nicotine addiction.

The Insula: A Brain Stimulation Target for the Treatment of Addiction

Substance use disorders (SUDs) are a growing public health concern with only a limited number of approved treatments. However, even approved treatments are subject to limited efficacy with high long-term relapse rates. Current treatment approaches are typically a combination of pharmacotherapies and behavioral counselling. Growing evidence and technological advances suggest the potential of brain stimulation techniques for the treatment of SUDs. There are three main brain stimulation techniques that are outlined in this review: transcranial magnetic stimulation (TMS), transcranial direct current stimulation (tDCS), and deep brain stimulation (DBS). The insula, a region of the cerebral cortex, is known to be involved in critical aspects underlying SUDs, such as interoception, decision making, anxiety, pain perception, cognition, mood, threat recognition, and conscious urges. This review focuses on both the preclinical and clinical evidence demonstrating the role of the insula in addiction, thereby demonstrating its promise as a target for brain stimulation. Future research should evaluate the optimal parameters for brain stimulation of the insula, through the use of relevant biomarkers and clinical outcomes for SUDs.

Alterations in resting-state functional connectivity in substance use disorders and treatment implications

Substance use disorders (SUD) are diseases of the brain, characterized by aberrant functioning in the neural circuitry of the brain. Resting state functional connectivity (rsFC) can illuminate these functional changes by measuring the temporal coherence of low-frequency fluctuations of the blood oxygenation level-dependent magnetic resonance imaging signal in contiguous or non-contiguous regions of the brain. Because this data is easy to obtain and analyze, and therefore fairly inexpensive, it holds promise for defining biological treatment targets in SUD, which could help maximize the efficacy of existing clinical interventions and develop new ones. In an effort to identify the most likely "treatment targets" obtainable with rsFC we summarize existing research in SUD focused on 1) the relationships between rsFC and functionality within important psychological domains which are believed to underlie relapse vulnerability 2) changes in rsFC from satiety to deprived or abstinent states 3) baseline rsFC correlates of treatment outcome and 4) changes in rsFC induced by treatment interventions which improve clinical outcomes and reduce relapse risk. Converging evidence indicates that likely "treatment target" candidates, emerging consistently in all four sections, are reduced connectivity within executive control network (ECN) and between ECN and salience network (SN). Other potential treatment targets also show promise, but the literature is sparse and more research is needed. Future research directions include data-driven prediction analyses and rsFC analyses with longitudinal datasets that incorporate time since last use into analysis to account for drug withdrawal. Once the most reliable biological markers are identified, they can be used for treatment matching, during preliminary testing of new pharmacological compounds to establish clinical potential ("target engagement") prior to carrying out costly clinical trials, and for generating hypotheses for medication repurposing.

The thalamo-cortical resting state functional connectivity and abstinence-induced craving in young smokers

Craving is a significant predicator of smoking relapse. Thus, revealing the neural correlates of craving to smoke in young smokers is important to improve the success of quit attempts. The abstinence-induced craving to smoke has not been explored extensively, although previous studies had investigated the neural substrates of cue-induced craving. Especially, the critical roles of thalamus had been revealed in cigarettes smoking. However, the implication of thalamus resting state functional connectivity (RSFC) in abstinence-induced craving remains unclear. In the current study, by employing a within-subject design in 25 young smokers, both the left and right thalamus RSFC patterns differences were investigated between smoking abstinence condition and smoking satiety condition in young smokers. Moreover, a correlation analysis was employed to assess the relationship between these RSFC changes and abstinence-induced changes in subjective craving. We found young smokers in abstinence state showed reduced RSFC between the left thalamus and right dorsal lateral prefrontal cortex (dlPFC) as well as the right anterior cingulate cortex (ACC) compared with smoking satiety state. There were no significant different RSFC of right thalamus detected across the two sessions. Additionally, the left thalamus-right dlPFC RSFC changes were correlated with the changes in craving induced by 12-h abstinence (i.e., abstinence minus satiety). The present findings provides new evidence that abstinence-induced cravings to smoke are associated with abnormal thalamus RSFC and may shed new insights into the neural mechanism of abstinence-induced craving in young smokers.

Smoking and Promoter-Specific Deoxyribonucleic Acid Methylation of the Atrial Natriuretic Peptide Gene: Methylation of Smokers and Non-Smokers Differs Significantly during Withdrawal

BACKGROUND

Atrial natriuretic peptide (ANP) is well known in psychiatric disorders to modulate hypothalamic-pituitary-adrenal axis activity. Disturbances of ANP have been described in early abstinent alcohol-dependent patients. This is the first longitudinal investigation on cytosine-phosphatidyl-guanine (CpG)-island promoter methylation of the ANP gene in the blood of tobacco-dependent patients.

METHODS

In a longitudinal approach, we investigated whether changes in ANP serum levels correlated to CpG methylation of the respective gene promoters on days 1, 7, and 14 of tobacco withdrawal.

RESULTS AND CONCLUSION

Compared to non-smokers, promoter-related deoxyribonucleic acid methylation of the ANP promoter was significantly elevated on days 7 and 14 of withdrawal in tobacco-dependent patients. Baseline methylation status of the ANP promoter was not significantly different from controls, arguing for an impaired regulation during withdrawal.