Associations Between Smoking Abstinence, Inhibitory Control, and Smoking Behavior: An fMRI Study

Regulation of craving and underlying resting-state neural circuitry predict hazard of smoking lapse

Among individuals with substance use disorders, clinical outcomes may be improved by identifying brain-behavior models that predict drug re/lapse vulnerabilities such as the ability to regulate drug cravings and inhibit drug use. In a sample of nicotine-dependent adult cigarette smokers (N = 213), this laboratory study examined associations between regulation of craving (ROC) efficacy and smoking lapse, utilized functional connectivity multivariate pattern analysis (FC-MVPA) and seed-based connectivity (SBC) analyses to identify resting-state neural circuitry underlying ROC efficacy, and then examined if the identified ROC-mediated circuitry predicted hazard of smoking lapse. Regarding behavior, worse ROC efficacy predicted a greater hazard of smoking lapse. Regarding brain and behavior, FC-MVPA identified 29 brain-wide functional clusters associated with ROC efficacy. Follow-up SBC analyses using 9 of the FC-MVPA-derived clusters identified a total of 64 resting-state edges (i.e., cluster-to-cluster connections) underlying ROC efficacy, 10 of which were also associated with the hazard of smoking lapse. ROC efficacy edges also associated with smoking lapse were largely composed of connections between frontal-striatal-limbic clusters and sensory-motor clusters and better behavioral outcomes were associated with stronger resting-state FC. Findings suggest that both ROC efficacy and underlying resting-state neural circuitry may inform prediction models of re/lapse vulnerabilities and serve as treatment targets for cessation interventions.

Genetic Correlation and Mendelian Randomization Analysis Revealed an Unidirectional Causal Relationship Between Left Caudal Middle Frontal Surface Area and Cigarette Consumption

OBJECTIVE

Previous studies have discovered a correlation between cigarette smoking and cortical thickness and surface area, but the causal relationship remains unclear. The objective of this investigation is to scrutinize the causal association between them.

METHODS

To derive summary statistics from a genome-wide association study (GWAS) on cortical thickness, surface area, and four smoking behaviors: 1) age of initiation of regular smoking (AgeSmk); 2) smoking initiation (SmkInit); 3) smoking cessation (SmkCes); 4) cigarettes per day (CigDay). Linkage disequilibrium score regression (LDSC) was employed to examine genetic association analysis. Furthermore, for traits with significant genetic associations, Mendelian randomization (MR) analyses were conducted.

RESULTS

The LDSC analysis revealed nominal genetic correlations between AgeSmk and right precentral surface area, left caudal anterior cingulate surface area, left cuneus surface area, left inferior parietal surface area, and right caudal anterior cingulate thickness, as well as between CigDay and left caudal middle frontal surface area, between SmkCes and left entorhinal thickness, and between SmkInit and left rostral anterior cingulate surface area, right rostral anterior cingulate thickness, and right superior frontal thickness (rg=-0.36-0.29, p<0.05). MR analysis showed a unidirectional causal association between left caudal middle frontal surface area and CigDay (βIVW=0.056, pBonferroni=2×10-4).

CONCLUSION

Left caudal middle frontal surface area has the potential to serve as a significant predictor of smoking behavior.

Inhibitory control in the sober state as a function of alcohol sensitivity: a pilot functional magnetic resonance imaging (fMRI) study

Introduction

Lower sensitivity (LS) to acute alcohol promotes hazardous alcohol use, increasing risk for alcohol use disorder (AUD). Compared to peers with high sensitivity (HS), LS individuals exhibit amplified responses to alcohol cues and difficulty exerting inhibitory control (IC) over those cued responses. However, it is unclear whether LS and HS individuals differ in neural or behavioral responses when exerting IC over affectively neutral prepotent responses (i.e., domain-general IC). This fMRI pilot study examined domain-general IC and its neural correlates in young adult LS and HS individuals.

Methods

Participants (N = 32, M age = 20.3) were recruited based on their Alcohol Sensitivity Questionnaire responses (HS: n = 16; LS: n = 16; 9 females/group) to complete an event-related fMRI IC task in a sober state. Retrospective assessments of alcohol craving, consumption, and problems were taken outside the lab.

Results

Although IC performance (accuracy) was numerically lower for the LS group (M[SD] = 0.527[0.125]) compared to the HS group (M[SD] = 0.595[0.124]), no significant difference was detected [t(30) = 1.55, p = 0.132]. Across groups, IC-related activity was observed in bilateral fronto-cortico-striatal circuitry, including dorsal striatum (DS) and dorsal/supragenual anterior cingulate cortex (dACC). Within group HS, IC-related dACC activity was greater among individuals reporting less intense (b-95 CI = [-0.201, -0.041], p = 0.004) and less frequent alcohol craving experiences (b-95 CI = [-0.131, 0.005], p = 0.068), whereas in group LS, IC-related dACC activity was greater among individuals reporting more intense (b-95 CI = [0.009, 0.140], p = 0.028) and more frequent alcohol craving experiences (b-95 CI = [0.022, 0.128], p = 0.007).

Discussion

In sum, while LS and HS individuals demonstrated similar domain-general IC performance and recruited similar neural resources to perform IC, findings suggest that compensatory over-activation of frontocortical nodes of the fronto-cortico-striatal IC circuitry may be related to affective-motivational aspects of AUD symptomatology (craving in daily life) among LS individuals. Based on these preliminary findings, future studies with larger samples are warranted to determine the extent to which domain-general IC performance associated with fronto-cortico-striatal IC circuit activation contributes to the alcohol use pathophysiology, and whether therapeutic interventions (e.g., non-invasive brain stimulation) targeting fronto-cortico-striatal IC circuitry may decrease AUD symptomatology.

Associations Between the Wisconsin Inventory of Smoking Dependence Motives and Regional Brain Volumes in Adult Smokers

INTRODUCTION

The Wisconsin Inventory of Smoking Dependence Motives (WISDM-68) is a 68-item questionnaire to assess nicotine dependence as a multifactorial construct based on 13 theoretically derived smoking motives. Chronic smoking is associated with structural changes in brain regions implicated in the maintenance of smoking behavior; however, associations between brain morphometry and the various reinforcing components of smoking behavior remain unexamined. The present study investigated the potential association between smoking dependence motives and regional brain volumes in a cohort of 254 adult smokers.

AIMS AND METHODS

The WISDM-68 was administered to participants at the baseline session. Structural magnetic resonance brain imaging (MRI) data from 254 adult smokers (Mage = 42.7 ± 11.4) with moderate to severe nicotine dependence (MFTND = 5.4 ± 2.0) smoking for at least 2 years (Myears = 24.3 ± 11.8) were collected and analyzed with Freesurfer.

RESULTS

Vertex-wise cluster analysis revealed that high scores on the WISDM-68 composite, secondary dependence motives (SDM) composite, and multiple SDM subscales were associated with lower cortical volume in the right lateral prefrontal cortex (cluster-wise p's < .035). Analysis of subcortical volumes (ie, nucleus accumbens, amygdala, caudate, and pallidum) revealed several significant associations with WISDM-68 subscales, dependence severity (Fagerström Test for Nicotine Dependence), and overall exposure (pack-years). No significant associations between cortical volume and other nicotine dependence measures or pack-years were observed.

CONCLUSIONS

Results suggest that smoking motives may play a larger role in cortical abnormalities than addiction severity and smoking exposure per se, whereas subcortical volumes are associated with smoking motives, addiction severity, and smoking exposure.

IMPLICATIONS

The present study reports novel associations between the various reinforcing components of smoking behavior assessed by the WISDM-68 and regional brain volumes. Results suggest that the underlying emotional, cognitive, and sensory processes that drive non-compulsive smoking behaviors may play a larger role in gray matter abnormalities of smokers than smoking exposure or addiction severity.

Effects of Hyperdirect Pathway Theta Burst Transcranial Magnetic Stimulation on Inhibitory Control, Craving, and Smoking in Adults With Nicotine Dependence: A Double-Blind, Randomized Crossover Trial

BACKGROUND

Nicotine dependence is associated with dysregulated hyperdirect pathway (HDP)-mediated inhibitory control (IC). However, there are currently no evidence-based treatments that have been shown to target the HDP to improve IC and reduce cigarette cravings and smoking.

METHODS

Following a baseline nonstimulation control session, this study (N = 37; female: n = 17) used a double-blind, randomized crossover design to examine the behavioral and neural effects of intermittent theta burst stimulation (iTBS) and continuous TBS (cTBS) to the right inferior frontal gyrus (rIFG)-a key cortical node of the HDP. Associations between treatment effects were also explored.

RESULTS

At baseline, HDP IC task-state functional connectivity was positively associated with IC task performance, which confirmed the association between HDP circuit function and IC. Compared with iTBS, rIFG cTBS improved IC task performance. Compared with the baseline nonstimulation control session, both TBS conditions reduced cigarette craving and smoking; however, although craving and smoking were lower for cTBS, no differences were found between the two active conditions. In addition, although HDP IC task-state functional connectivity was greater following cTBS than iTBS, there was no significant difference between conditions. Finally, cTBS-induced improvement in IC task performance was associated with reduced craving, and cTBS-induced reduction in craving was associated with reduced smoking.

CONCLUSIONS

These findings warrant further investigation into the effects of rIFG cTBS for increasing IC and reducing craving and smoking among individuals with nicotine dependence. Future sham-controlled cTBS studies may help further elucidate the mechanisms by which rIFG cTBS mediates IC and smoking behavior.

Right inferior frontal gyrus theta-burst stimulation reduces smoking behaviors and strengthens fronto-striatal-limbic resting-state functional connectivity: a randomized crossover trial

Introduction

Functional and anatomical irregularities in the right inferior frontal gyrus (rIFG), a ventrolateral prefrontal region that mediates top-down inhibitory control over prepotent behavioral responding, are implicated in the ongoing maintenance of nicotine dependence (ND). However, there is little research on the effects of neuromodulation of the rIFG on smoking behavior, inhibitory control, and resting-state functional connectivity (rsFC) among individuals with ND.

Methods

In this double-blind, crossover, theta-burst stimulation (TBS) study, adults with ND (N = 31; female: n = 15) completed a baseline session and were then randomized to two counterbalanced sessions of functionally neuronavigated TBS to the rIFG: continuous TBS (cTBS) on 1 day and intermittent TBS (iTBS) on another. Differences in cigarette cravings, smoking, and fronto-striatal-limbic rsFC were assessed.

Results

Relative to baseline, cTBS significantly reduced appetitive and withdrawal cravings immediately after treatment. The effects of cTBS on withdrawal craving persisted for 24 h, as well as produced a reduction in smoking. Furthermore, cTBS significantly strengthened rsFC between the rIFG pars opercularis and subcallosal cingulate (fronto-striatal circuit), and between the rIFG pars opercularis and the right posterior parahippocampal gyrus (fronto-limbic circuit). At post-24 h, cTBS-induced increase in fronto-striatal rsFC was significantly associated with less appetitive craving, while the increase in fronto-limbic rsFC was significantly associated with less withdrawal craving and smoking.

Discussion

These findings warrant further investigation into the potential value of rIFG cTBS to attenuate smoking behavior among individuals with ND.

Neurophysiological Deficits During Reappraisal of Negative Emotional Stimuli in Opioid Misuse

BACKGROUND

Opioid misuse is hypothesized to compromise the ability to regulate negative emotions, as manifested through visceral and peripheral physiological signals. However, neurophysiological impairment of top-down cognitive emotion regulation in opioid misuse has not previously been shown.

METHODS

Patients with chronic pain who had been taking opioids for 90 days or longer (N = 149; female, n = 98) underwent a negative emotion regulation task with electroencephalography. Participants were instructed to view or reappraise negative images presented for 3 seconds. Using a validated cutoff score on the Current Opioid Misuse Measure, participants were classified as exhibiting aberrant drug-related behavior consistent with opioid misuse (MISUSE+) or as being low risk for opioid misuse (MISUSE-). Participants reported their craving in response to negative emotions over the past week.

RESULTS

We observed a group × condition interaction (p = .003) such that the MISUSE- group decreased the late positive potential of the electroencephalography during reappraisal, whereas the MISUSE+ group showed increased late positive potential during reappraisal. This deficit in negative emotion regulation remained significant after controlling for an array of potential confounding variables, including opioid dose, pain, and depression. Heightened late positive potential during reappraisal was associated with more severe opioid craving.

CONCLUSIONS

Opioid misuse may occasion top-down deficits in emotional regulation that begin as early as 400 ms after presentation of negative stimuli. It remains unknown whether emotion dysregulation is the cause, correlate, or consequence of opioid misuse. Nonetheless, targeting emotion dysregulation in opioid misuse with reappraisal-focused interventions may represent an important treatment approach.