Effect of Low-Frequency Repetitive Transcranial Magnetic Stimulation on Impulse Inhibition in Abstinent Patients With Methamphetamine Addiction: A Randomized Clinical Trial

Transcranial magnetic stimulation for methamphetamine use disorder: A scoping review within the neurocircuitry model of addiction

The use of methamphetamine in the United States is increasing, contributing now to the "fourth wave" in the national opioid epidemic crisis. People who suffer from methamphetamine use disorder (MUD) have a higher risk of death. No pharmacological interventions are approved by the FDA and psychosocial interventions are only moderately effective. Transcranial Magnetic Stimulation (TMS) is a relatively novel FDA-cleared intervention for the treatment of Major Depressive Disorder (MDD) and other neuropsychiatric conditions. Several lines of research suggest that TMS could be useful for the treatment of addictive disorders, including MUD. We will review those published clinical trials that show potential effects on craving reduction of TMS when applied over the dorsolateral prefrontal cortex (DLPFC) also highlighting some limitations that affect their generalizability and applicability. We propose the use of the Koob and Volkow's neurocircuitry model of addiction as a frame to explain the brain effects of TMS in patients with MUD. We will finally discuss new venues that could lead to a more individualized and effective treatment of this complex disorder including the use of neuroimaging, the exploration of different areas of the brain such as the frontopolar cortex or the salience network and the use of biomarkers.

Exploring the interplay between addiction and time perception: A systematic review and meta-analysis

Prior studies have investigated the immediate impacts of substances on temporal perception, the impact of temporal outlook, and the consequences of modified temporal perception on addictive behaviors. These inquiries have provided valuable perspectives on the intricate associations between addiction and time perception, enriching the groundwork for forthcoming research and therapeutic strategies. This comprehensive review aims to further explore intricate correlation among diverse addictive substances-namely alcohol, cannabis, nicotine, opioids-and non-substance addictions such as internet gaming, elucidating their influence on temporal perception. Adhering to the PICOS method and adhering to PRISMA guidelines, we systematically reviewed and critically evaluated all existing research concerning temporal perception in individuals with substance and non-substance use disorders. Specifically, our analyses involved 31 pertinent articles encompassing six unique groups-alcohol, nicotine, cannabis, stimulants, opioids, and internet-related addictions-sourced from a pool of 551 papers. The findings revealed differences in time perception between addicts and control groups, as indicated by medium to large effect sizes (Hedge's g = 0.8, p < 0.001). However, the nature of these differences-whether they predominantly involve time overestimation or underestimation-is not yet definitively clear. This variability underscores the complexity of the relationship between addiction and temporal perception, paving the way for further research to unravel these intricate dynamics.

Association between sleep problems and impulsivity mediated through regional homogeneity abnormalities in male methamphetamine abstainers

Sleep problems and impulsivity frequently occur in methamphetamine (MA) abstainers and are linked to aberrant brain function. However, the interplay between these factors remains poorly understood. This study aimed to investigate the relationship between sleep, impulsivity, and regional homogeneity (ReHo) through mediation analysis in MA abstainers. 46 MA abstainers and 44 healthy controls were included. Impulsivity and sleep problems were evaluated using the Barratt Impulsivity Scale and the Pittsburgh Sleep Quality Scale, respectively. ReHo, indicative of local brain spontaneous neural activity, was assessed using resting-state functional magnetic resonance imaging. Results unveiled correlations between different dimensions of impulsivity and ReHo values in specific brain regions. Motor impulsivity correlated with ReHo values in the left postcentral gyrus and left precentral gyrus, while non-planning impulsivity was only associated with ReHo values in the left precentral gyrus. Additionally, the need for sleep medications correlated with ReHo values in the left precentral gyrus and bilateral postcentral gyrus. Also, the need for sleep medications was positively correlated with cognitive impulsivity and motor impulsivity. Mediation analysis indicated that reduced ReHo values in the left precentral gyrus mediated the association between impulsivity and the need for sleep medications. These findings imply that addressing sleep problems, especially the need for sleep medications, might augment spontaneous neural activity in specific brain regions linked to impulsivity among MA abstainers. This underscores the importance of integrating sleep interventions into comprehensive treatment strategies for MA abstainers.

Effects of brief mindfulness training on smoking cue-reactivity in tobacco use disorder: Study protocol for a randomized controlled trial

BACKGROUND

The prevalence of Tobacco Use Disorder (TUD) represents a significant and pressing global public health concern, with far-reaching and deleterious consequences for individuals, communities, and healthcare systems. The craving caused by smoking cue is an important trigger for relapse, fundamentally hindering the cessation of cigarette smoking. Mindfulness interventions focusing on cue-reactivity was effective for the treatment of related dependence. Brief mindfulness training (BMT) meets the short-term needs for intervention but the effects still need to be examined. The objective of the present study is to investigate the impact of BMT intervention on smoking cue-reactivity among Chinese college students with TUD, to uncover the dynamic models of brain function involved in this process.

METHOD

A randomized control trial (RCT) based on electroencephalography (EEG) was designed. We aim to recruit 90 participants and randomly assign to the BMT and control group (CON) with 1:1 ratio. A brief mindfulness training will be administered to experimental group. After the intervention, data collection will be conducted in the follow-up stage with 5 timepoints of assessments. EEG data will be recorded during the smoking cue-reactivity task and 'STOP' brief mindfulness task. The primary outcomes include subjective reports of smoking craving, changes in EEG indicators, and mindfulness measures. The secondary outcomes will be daily smoking behaviours, affect and impulsivity, as well as indicators reflecting correlation between mindfulness and smoking cue-reactivity. To evaluate the impact of mindfulness training, a series of linear mixed-effects models will be employed. Specifically, within-group effects will be examined by analysing the longitudinal data. Additionally, the effect size for all statistical measurements will be reported, offering a comprehensive view of the observed effects.

DISCUSSION

The current study aims to assess the impact of brief mindfulness-based intervention on smoking cue-reactivity in TUD. It also expected to enhance our understanding of the underlying processes involved in brain function and explore potential EEG biomarkers at multiple time points.

TRIAL REGISTRATION

Trial registration number: ChiCTR2300069363, registered on 14 March 2023. Protocol Version 1.0., 10 April 2023.

A systematic review and meta-analysis of neuromodulation therapies for substance use disorders

While pharmacological, behavioral and psychosocial treatments are available for substance use disorders (SUDs), they are not always effective or well-tolerated. Neuromodulation (NM) methods, including repetitive transcranial magnetic stimulation (rTMS), transcranial direct current stimulation (tDCS) and deep brain stimulation (DBS) may address SUDs by targeting addiction neurocircuitry. We evaluated the efficacy of NM to improve behavioral outcomes in SUDs. A systematic literature search was performed on MEDLINE, PsychINFO, and PubMed databases and a list of search terms for four key concepts (SUD, rTMS, tDCS, DBS) was applied. Ninety-four studies were identified that examined the effects of rTMS, tDCS, and DBS on substance use outcomes (e.g., craving, consumption, and relapse) amongst individuals with SUDs including alcohol, tobacco, cannabis, stimulants, and opioids. Meta-analyses were performed for alcohol and tobacco studies using rTMS and tDCS. We found that rTMS reduced substance use and craving, as indicated by medium to large effect sizes (Hedge's g > 0.5). Results were most encouraging when multiple stimulation sessions were applied, and the left dorsolateral prefrontal cortex (DLPFC) was targeted. tDCS also produced medium effect sizes for drug use and craving, though they were highly variable and less robust than rTMS; right anodal DLPFC stimulation appeared to be most efficacious. DBS studies were typically small, uncontrolled studies, but showed promise in reducing misuse of multiple substances. NM may be promising for the treatment of SUDs. Future studies should determine underlying neural mechanisms of NM, and further evaluate extended treatment durations, accelerated administration protocols and long-term outcomes with biochemical verification of substance use.

Managing substance use in patients receiving therapeutic repetitive transcranial magnetic stimulation: A scoping review

Repetitive Transcranial Magnetic Stimulation (rTMS) is an invaluable treatment option for neuropsychiatric disorders. Co-occurring recreational and nonmedical substance use can be common in those presenting for rTMS treatment, and it is unknown how it may affect the safety and efficacy of rTMS for the treatment of currently approved neuropsychiatric indications. This scoping review aimed to map the literature on humans receiving rTMS and had a history of any type of substance use. The search identified 274 articles providing information on inclusion/exclusion criteria, withdrawal criteria, safety protocols, type of rTMS and treatment parameters, adverse events and effect on primary outcomes that related to substance use. There are neurophysiological effects of substance use on cortical excitability, although the relevance to clinical rTMS practice is unknown. The current literature supports the safety and feasibility of delivering rTMS to those who have co-occurring neuropsychiatric disorder and substance use. However, specific details on how varying degrees of substance use alters the safety, efficacy, and mechanisms of rTMS remains poorly described.

Neural substrates of behavioral inhibitory control during the two-choice oddball task: functional neuroimaging evidence

Background

Behavioral inhibitory control (BIC) depicts a cognitive function of inhibiting inappropriate dominant responses to meet the context requirement. Despite abundant research into neural substrates of BIC during the go/no-go and stop signal tasks, these tasks were consistently shown hard to isolate neural processes of response inhibition, which is of primary interest, from those of response generation. Therefore, it is necessary to explore neural substrates of BIC using the two-choice oddball (TCO) task, whose design of dual responses is thought to produce an inhibition effect free of the confounds of response generation.

Objective

The current study aims at depicting neural substrates of performing behavioral inhibitory control in the two-choice oddball task, which designs dual responses to balance response generation. Also, neural substrates of performing BIC during this task are compared with those in the go/no-go task, which designs a motor response in a single condition.

Methods

The present study integrated go/no-go (GNG) and TCO tasks into a new Three-Choice BIC paradigm, which consists of standard (75%), deviant (12.5%), and no-go (12.5%) conditions simultaneously. Forty-eight college students participated in this experiment, which required them to respond to standard (frequent) and deviant stimuli by pressing different keys, while inhibiting motor response to no-go stimuli. Conjunction analysis and ROI (region of interest) analysis were adopted to identify the unique neural mechanisms that subserve the processes of BIC.

Results

Both tasks are effective in assessing BIC function, reflected by the significantly lower accuracy of no-go compared to standard condition in GNG, and the significantly lower accuracy and longer reaction time of deviant compared to standard condition in TCO. However, there were no significant differences between deviant and no-go conditions in accuracy. Moreover, functional neuroimaging has demonstrated that the anterior cingulate cortex (ACC) activation was observed for no-go vs. standard contrast in the GNG task, but not in deviant vs. standard contrast in the TCO task, suggesting that ACC involvement is not a necessary component of BIC. Second, ROI analysis of areas that were co-activated in TCO and GNG showed co-activations in the right inferior frontal cortex (triangle and orbital), with the signals in the TCO task significantly higher than those in the GNG task.

Conclusions

These findings show that the designed responses to both standard and deviant stimuli in the TCO task, compared to the GNG task, produced a more prominent prefrontal inhibitory processing and extinguished an unnecessary component of ACC activation during BIC. This implies that prefrontal involvement, but not that of ACC, is mandatory for the successful performance of inhibiting prepotent behaviors.

The effect of repetitive transcranial magnetic stimulation on electroencephalography microstates of patients with heroin-addiction

The effects of transcranial magnetic stimulation in treating substance use disorders are gaining attention; however, most existing studies used subjective measures to examine the treatment effects. Objective electroencephalography (EEG)-based microstate analysis is important for measuring the efficacy of transcranial magnetic stimulation in patients with heroin addiction. We investigated dynamic brain activity changes in individuals with heroin addiction after transcranial magnetic stimulation using microstate indicators. Thirty-two patients received intermittent theta-burst stimulation (iTBS) over the left dorsolateral prefrontal cortex. Resting-state EEG data were collected pre-intervention and 10 days post-intervention. The feature values of the significantly different microstate classes were computed using a K-means clustering algorithm. Four EEG microstate classes (A-D) were noted. There were significant increases in the duration, occurrence, and contribution of microstate class A after the iTBS intervention. K-means classification accuracy reached 81.5%. The EEG microstate is an effective improvement indicator in patients with heroin addiction treated with iTBS. Microstates were examined using machine learning; this method effectively classified the pre- and post-intervention cohorts among patients with heroin addiction and healthy individuals. Using EEG microstate to measure heroin addiction and further exploring the effect of iTBS in patients with heroin addiction merit clinical investigation.

Transcranial Stimulation for the Treatment of Stimulant Use Disorder

The increasing prevalence of stimulant use disorder (StUD) involving methamphetamine and cocaine has been a growing healthcare concern in the United States. Cocaine usage is associated with atherosclerosis, systolic and diastolic dysfunction, and arrhythmias. Furthermore, approximately one of every four MIs is cocaine-induced among patients aged 18 to 45. Methamphetamine use has been associated with nerve terminal damage in the dopaminergic system resulting in impaired motor function, cognitive decline, and co-morbid psychiatric disorders. Current treatment options for StUD are extremely limited, and there are currently no FDA-approved pharmacotherapies. Behavioral interventions are considered first-line treatment; however, in a recent meta-analysis comparing behavioral treatment options for cocaine, contingency management programs provided the only significant reduction in use. Current evidence points to the potential of various neuromodulation techniques as the next best modality in treating StUD. The most promising evidence thus far has been transcranial magnetic stimulation which several studies have shown to reduce risk factors associated with relapse. Another more invasive neuromodulation technique being studied is deep-brain stimulation, which has shown promising results in its ability to modulate reward circuits to treat addiction. Results showing the impact of transcranial magnetic stimulation (TMS) in the treatment of StUD are limited by the lack of studies conducted and the limited understanding of the neurological involvement driving addiction-based diseases such as StUD. Future studies should seek to provide data on consumption-reducing effects rather than craving evaluations.

Preventing incubation of drug craving to treat drug relapse: from bench to bedside

In 1986, Gawin and Kleber reported a progressive increase in cue-induced drug craving in individuals with cocaine use disorders during prolonged abstinence. After years of controversy, as of 2001, this phenomenon was confirmed in rodent studies using self-administration model, and defined as the incubation of drug craving. The intensification of cue-induced drug craving after withdrawal exposes abstinent individuals to a high risk of relapse, which urged us to develop effective interventions to prevent incubated craving. Substantial achievements have been made in deciphering the neural mechanisms, with potential implications for reducing drug craving and preventing the relapse. The present review discusses promising drug targets that have been well investigated in animal studies, including some neurotransmitters, neuropeptides, neurotrophic factors, and epigenetic markers. We also discuss translational exploitation and challenges in the field of the incubation of drug craving, providing insights into future investigations and highlighting the potential of pharmacological interventions, environment-based interventions, and neuromodulation techniques.

Psychological Effects of Repetitive Transcranial Magnetic Stimulation on Individuals With Methamphetamine Use Disorder: A Systematic Review and Meta-Analysis

OBJECTIVE

To evaluate the effects of rTMS on drug craving, depression, anxiety, sleep, and cognitive function in methamphetamine (MA) dependent individuals.

DATA SOURCES AND METHODS

Randomized controlled trials (RCTs) of rTMS interventions for MA-dependent patients were searched through PubMed, Embase, Cochrane Library, Web of Science, Chinese National Knowledge Infrastructure (CNKI), Wanfang database, Chongqing Vipers (VIP) and China Biomedical Literature Database (CBLD). The included literature was statistically processed using Revman 5.4, and STATA 16.0 for sensitivity and bias analysis.

RESULTS

A total of 13 papers were included, and the results of the meta-analysis showed that rTMS was effective in reducing craving scores (SMD = -1.53, 95%CI:-2.08 ∼ -0.98, p < 0.00001), improving depression (SMD = -0.32, 95%CI:-0.58 ∼ -0.07, p = 0.01) and sleep scores (WMD = -1.26, 95%CI:-2.26 ∼ -0.27, p = 0.01), but had no effect on anxiety scores (SMD = -0.42, 95%CI:-0.88 ∼ 0.03, p = 0.07); in terms of cognitive function, there were improvements in the international shopping list task (ISL), Groton maze learning task (GML) and continuous paired association learning task (CPAL), except for no effect on the social emotional cognition task (SEC) and two back task (TWOB). Subgroup analysis showed significant differences in the effects of different intervention period on craving in MA-dependent individuals.

CONCLUSION

rTMS was effective in reducing MA dependent individuals' cravings, alleviating depressive symptoms, improving sleep quality and language learning, collaborative learning and executive skills. Due to the small sample size of this study, a large number of RCTs are needed to validate this.

Neurobiological mechanisms and related clinical treatment of addiction: a review

Drug addiction or substance use disorder (SUD), has been conceptualized as a three-stage (i.e. binge/intoxication, withdrawal/negative affect, and preoccupation/anticipation/craving) recurring cycle that involves complex changes in neuroplasticity, reward, motivation, desire, stress, memory, and cognitive control, and other related brain regions and brain circuits. Neuroimaging approaches, including magnetic resonance imaging, have been key to mapping neurobiological changes correlated to complex brain regions of SUD. In this review, we highlight the neurobiological mechanisms of these three stages of addiction. The abnormal activity of the ventral tegmental, nucleus accumbens, and caudate nucleus in the binge/intoxication stage involve the reward circuit of the midbrain limbic system. The changes in the orbitofrontal cortex, dorsolateral prefrontal cortex, amygdala, and hypothalamus emotional system in the withdrawal/negative affect stage involve increases in negative emotional states, dysphoric-like effects, and stress-like responses. The dysregulation of the insula and prefrontal lobes is associated with craving in the anticipation stage. Then, we review the present treatments of SUD based on these neuroimaging findings. Finally, we conclude that SUD is a chronically relapsing disorder with complex neurobiological mechanisms and multimodal stages, of which the craving stage with high relapse rate may be the key element in treatment efficacy of SUD. Precise interventions targeting different stages of SUD and characteristics of individuals might serve as a potential therapeutic strategy for SUD.

Multiple comparison of different noninvasive brain stimulation and pharmacologic interventions in patients with methamphetamine use disorders: A network meta-analysis of randomized controlled trials

AIM

In recent decades, the prevalence of amphetamine and methamphetamine use disorders has at least doubled in some regions/countries, with accompanying high risks of drug overdose-associated mortality. Noninvasive brain stimulation (NIBS) methods may be effective treatments. However, the comparative efficacy of the NIBS protocol for amphetamine/methamphetamine use disorder (AUD/MUD) remains unknown to date. The aim of this network meta-analysis (NMA) was to compare the efficacy and acceptability of various NIBS methods/protocols for AUD/MUD management.

METHODS

A frequentist model-based NMA was conducted. We included randomized controlled trials (RCTs) that investigated the efficacy of NIBS and guideline-recommended pharmacologic treatments to reduce craving severity in patients with either AUD or MUD.

RESULTS

Twenty-two RCTs including 1888 participants met the eligibility criteria. Compared with the sham/placebo group (study = 19, subjects = 891), a combination of intermittent theta burst stimulation over the left dorsolateral prefrontal cortex (DLPFC) and continuous TBS over the left ventromedial prefrontal cortex (study = 1, subjects = 19) was associated with the largest decreases in craving severity [standardized mean difference (SMD) = -1.50; 95% confidence intervals (95%CIs) = -2.70 to -0.31]. High-frequency repetitive transcranial magnetic stimulation over the left DLPFC was associated with the largest improvements in depression and quality of sleep (study = 3, subjects = 86) (SMD = -2.48; 95%CIs = -3.25 to -1.71 and SMD = -2.43; 95%CIs = -3.38 to -1.48, respectively). The drop-out rate of most investigated treatments did not significantly differ between groups.

CONCLUSION

The combined TBS protocol over the prefrontal cortex was associated with the greatest improvement in craving severity. Since few studies were available for inclusion, additional large-scale randomized controlled trials are warranted.

Effects of total sleep deprivation on execution lapses during vigilance tasks

Total sleep deprivation (TSD) results in reduced efficiency of cognitive resources. Moreover, when the available cognitive resources are less than required, individuals exhibit lapses in responsiveness. Accordingly, this study explored the effects of TSD on executive function and the characteristics of execution lapses. Functional near-infrared spectroscopy was used to monitor the prefrontal cortex's functional connections in resting and tasking states for various sleep deprivation durations. Data from participants' attentional performance test and self-reported fatigue were collected over 30 hours of wakefulness. Task performance was compared based on time of day, time on task, and reaction time. The results show that participants' arousal level significantly decreased post 14 hours (P < .05), while sleepiness increased. The prefrontal cortex connection and attentional performance dropped at the Window of Circadian Low (3:00 ~ 6:00). The number of execution lapses was higher during the initiation, inhibition, and fatigue phases and rose markedly post 14 hours of wakefulness. We conclude that maintaining better inhibition control requires a reasonable extension of the reaction time. Moreover, subjective perception is significantly correlated with task performance and right prefrontal connection strength. This study presents the scientific evidence for measures to address consistently long working hours and disrupted circadian rhythms.

High-frequency repetitive transcranial magnetic stimulation of the left dorsolateral prefrontal cortex reduces drug craving and improves decision-making ability in methamphetamine use disorder

Methamphetamine abuse is escalating worldwide. Its strong and irreversible neurotoxicity generally causes structural and functional changes in the brain. Repetitive transcranial magnetic stimulation (rTMS) as a non-invasive tool can be used to modulate neuronal activity, cortical excitability, and dopaminergic neurotransmission. This study aims to explore the efficacy of high-frequency rTMS in reducing drug craving and increasing decision-making ability for methamphetamine use disorder patients. Sixty-four methamphetamine use disorder patients were randomized to sham rTMS group and 10-Hz rTMS group. Visual analog scale (VAS) and Iowa game test (IGT) were used to evaluate drug craving and cognitive decision-making ability before and after treatment. Before the treatment, the two groups had no differences in the scores of VAS and IGT. After the intervention, VAS scores of 10-Hz rTMS group were significantly lower than that of sham rTMS group. In addition, the two groups had significant differences in the net score of IGT on block 4 and block 5, which favoured the 10-Hz rTMS group. Taken together, the present results suggest that High-frequency rTMS can be used to reduce drug craving and improve decision-making function for methamphetamine use disorder.

Partial recovery of the left DLPFC-right insula circuit with reduced craving in abstinent heroin users: a longitudinal study

The phenomenon of brain recovery after long-term abstinence has been reported in substance use disorders. However, few longitudinal studies have been conducted to observe the potential recovery in heroin users, and little is known about the neural mechanism underlying the decreased craving after prolonged abstinence. The 8-month longitudinal study was carried out in 29 heroin users and 30 healthy controls. By choosing the L_DLPFC, which was activated by the heroin cue as the seeding region, different brain connection patterns were compared between healthy controls and heroin users by using Granger causality analysis (GCA) at baseline. Then, a paired t test was employed to detect the potential recovery of L_DLPFC circuits after prolonged abstinence. The visual analog scale (VAS) and trail-making test-A (TMT-A) were adopted to investigate craving and cognitive control impairment, respectively. The neuroimaging changes were then correlated with behavioral improvements. Similar analyses were applied for the mirrored right DLPFC to verify the lateralization hypothesis of the DLPFC in addiction. In the longitudinal study, enhanced GCA coefficients were observed in the L_DLPFC-R_insula circuit of heroin users after long-term abstinence and were associated with craving score changes. At baseline, decreased GCA coefficients from the left DLPFC to the bilateral SMA and right putamen, together with the reduced GCA strength from the bilateral OFC to the left DLPFC, were found between HUs and HCs. Our findings extended the brain recovery phenomenon into the field of heroin and suggested that the increased regulation of the L_DLPFC over the insula after prolonged abstinence was important for craving inhibition.

High-frequency repetitive transcranial magnetic stimulation of the left dorsolateral prefrontal cortex may reduce impulsivity in patients with methamphetamine use disorders: A pilot study

Background

Individuals who use methamphetamine (MA) for a long period of time may experience decreased inhibition and increased impulsivity. In order to reduce impulsivity or improve inhibitory control ability, high-frequency repetitive transcranial magnetic stimulation (HF-rTMS) has attracted much attention of researchers. Recent studies on addiction have shown that rTMS can stimulate different brain regions to produce different therapeutic effects. Recent work also suggests that HF-rTMS over right dorsolateral prefrontal cortex (DLPFC) does not affect the impulsivity of patients with alcohol use disorder; while HF-rTMS over left DLPFC could improve the impulsivity of patients with alcohol use disorder and cigarette smokers. However, it should be noted that empirical studies applying HF-rTMS over left DLPFC of patients with MA use disorders (MAUD) (to evaluate its effect on impulsivity) are still lacking.

Methods

Twenty-nine patients with MAUD underwent five sessions of HF-rTMS on the left DLPFC per week for 4 consecutive weeks. The cue-induced craving and stop-signal and NoGo task were assessed pre-rTMS and post-rTMS (at the end of the 4-week rTMS treatment). In addition, 29 healthy controls were recruited. There was no rTMS intervention for the controls, the performance of the stop-signal and NoGo task was evaluated on them.

Results

In total, HF-rTMS of the left DLPFC significantly decreased MA-dependent patients’ cue-induced craving and stop-signal reaction time (SSRT). For SSRT, the pre-test of experimental group was significantly higher than the score of control group. In the experimental group, the pre-test score was significantly higher than the post-test score. For Go and stop-signal delay (SSD), the pre-test scores of the experimental group was significantly lower than the scores of the control group. No significant difference was found between the pre-test and the post-test scores of the experimental group.

Conclusion

Add-on HF-rTMS of left DLPFC may be an effective intervention for reducing impulsivity and cue-induced craving of patients with MAUD. Future research with a control group of MAUD that does not undergo the treatment is needed to confirm the effectiveness.

Influence of improved behavioral inhibition on decreased cue-induced craving in heroin use disorder: A preliminary intermittent theta burst stimulation study

BACKGROUND

Impaired behavioral inhibition is a critical factor in drug addiction and relapse. Repetitive transcranial magnetic stimulation (rTMS) reduces the craving of heroin-addicted individuals for drug-related cues. However, it is unclear whether this technique also improves impaired behavioral inhibition and how improved behavioral inhibition affects craving.

OBJECTIVE

The intermittent theta-burst stimulation (iTBS) has been recently shown to be non-inferior relative to rTMS for depression. Here, we aim to investigate the effect of iTBS on heroin-addicted individuals' behavioral inhibition and cue-induced craving and the relationship between the alteration of behavioral inhibition and craving.

METHOD

42 of 56 initially recruited individuals with the heroin-use disorder in the abstinent-course treatment were randomized to undergo active or sham iTBS to the left dorsolateral prefrontal cortex and received three daily iTBS treatments for 10 consecutive days. We measured participants' performance during a two-choice oddball task (80% standard and 20% deviant trials) and heroin-related cue-induced craving before and immediately after treatment.

RESULTS

The group that received active iTBS showed significantly improved two-choice oddball task performance after 10 days of intervention compared to both pre-intervention and the group who received sham iTBS. Similarly, a significant reduction in cue-induced craving was observed after following the intervention in the active iTBS group but not the sham iTBS group. The moderation model indicated that iTBS categories play a significant moderating role in the relationship between accuracy cost changing and altered cue-induced craving.

CONCLUSIONS

The iTBS treatment protocol positively affects behavioral inhibition in patients with heroin addiction. Improvements in behavioral inhibition can substantially reduce craving.

Transcranial magnetic stimulation versus transcutaneous neuromuscular electrical stimulation in post stroke dysphagia: A clinical randomized controlled trial

OBJECTIVES

To evaluate the efficacy of high-frequency repeated transcranial magnetic stimulation (rTMS) applied contralesionally versus transcutaneous neuromuscular electrical stimulation (TNES) in acute post-stroke dysphagic patients.

MATERIALS AND METHODS

A randomized, parallel, comparative, controlled trial was conducted on patients with acute ischemic stroke who were admitted to our department. Fifteen patients received rTMS, 15 patients received TNES, and 15 patients were recruited as a control group. Between the second and tenth days after a stroke, patients were enrolled. The study and follow-up periods were completed by all patients.

RESULTS

Among the screened patients, 45 (31.47%) right-handed patients were diagnosed with post-stroke dysphagia with a mean age of 60.53 ± 8.23 years. Immediately after intervention both rTMS and TNES groups significantly improve the swallowing disturbance questionnaire (SDQ) and penetration aspiration scale (PAS), compared to the control (p < 0.001 and p = 0.027), respectively. rTMS was more effective than TNES in reducing SDQ and PAS (p < 0.05). rTMS and TNES improved the Yale Pharyngeal Residue Severity Rating Scale (YPRSRS) significantly (p = 0.002); however, their efficacy was comparable (p > 0.05). A significant (p < 0.001) strong negative correlation was observed between the grade of weakness and all scores.

CONCLUSION

Our findings showed that high-frequency rTMS and TNES effectively improved the clinical condition of acute post-stroke dysphagic patients in terms of swallowing disturbance assessed by SDQ, pharyngeal residue assessed by YPRSRS, and the severity of penetration and aspiration events evaluated by PAS, compared to the controls. The outcomes of high-frequency rTMS were more favorable than those of TNES in terms of SDQ and PAS.

Reducing craving and consumption in individuals with drug addiction, obesity or overeating through neuromodulation intervention: a systematic review and meta-analysis of its follow-up effects

BACKGROUND AND AIMS

Non-invasive brain stimulation has shown potential in clinical applications aiming at reducing craving and consumption levels in individuals with drug addiction or overeating behaviour. However, it is unclear whether these intervention effects are maintained over time. This study aimed to measure the immediate, short- and long-term effects of excitatory transcranial direct current stimulation (tDCS) and high-frequency repetitive transcranial magnetic stimulation (rTMS) targeting at dorsolateral prefrontal cortex (dlPFC) in people with drug addiction or overeating.

METHODS

A systematic review and random effects meta-analysis. We included 20 articles (total of 22 studies using randomized controlled trials: 3 alcohol dependence, 3 drug dependence, 12 smoking, 4 overeating; total: 720 participants) from January 2000 to June 2020, which reported at least one follow-up assessment of craving, consumption or abstinence levels after the intervention. We compared effects of active versus sham stimulation immediately after the intervention and at the last follow-up assessment, as compared with baseline.

RESULTS

Excitatory neuromodulation of dlPFC activity reduced craving and consumption immediately after the intervention (craving: g = 0.734, CI = 0.447-1.021, P < 0.001; consumption: g = 0.527, CI = 0.309-0.745; P < 0.001), as well as during short-, mid- and long-term abstinence (craving: g = 0.677, CI = 0.440-0.914, P < 0.001; consumption: g = 0.445, CI = 0.245-0.645, P < 0.001; abstinence levels: g = 0.698, CI = 0.433-0.963, P < 0.001; average time of follow-up: 84 ± 83 days after last stimulation). Additional analysis demonstrated that the intervention effects were sustained in all populations studied (food, nicotine, alcohol or drug abuse) and with both stimulation techniques used (rTMS, tDCS). Interventions targeting at the left (vs right) hemisphere may be more effective.

CONCLUSIONS

Excitatory neuromodulation targeting the dorsolateral prefrontal cortex appears to lead to a sustained reduction of craving and consumption in individuals with addiction or overeating behaviour.

Repetitive Transcranial Magnetic Stimulation (rTMS) as a Promising Treatment for Craving in Stimulant Drugs and Behavioral Addiction: A Meta-Analysis

Addiction is a mental disorder with limited available treatment options. The therapeutic potential of repetitive transcranial magnetic stimulation (rTMS) on it, by targeting craving in particular, has been explored with heterogenous results. This meta-analysis uses updated evidence to assess overall rTMS efficacy on craving, differential effects between addiction types clustered into three groups (depressant (alcohol, cannabis, opiate), stimulant (nicotine, cocaine, methamphetamine), and behavioral addiction (gambling, eating disorder)), and stimulation settings. Studies on substance use, gambling, and eating disorders are included, with unrestricted stimulation settings, by searching the PubMed, Embase, PsycINFO, and Cochrane databases up to 30 April 2020. A total of 34 eligible studies (42 units of analysis) were identified. Because of highly significant heterogeneity in primary results, a sensitivity analysis was performed on a remaining sample of 26 studies (30 units of analysis). Analyses performed using random effects model revealed a small effect size favoring active rTMS over shamTMS stimulation in the reduction in craving. We found a significant difference between addiction types, with a persistent small effect only for stimulant and behavioral groups. In these groups we found no difference between the different combinations of target and frequency of stimulation, but a significant correlation between number of sessions and craving reduction. In conclusion, efficacy of rTMS on craving in stimulant and behavioral addiction was highlighted, but recommendations on optimal stimulation settings and its clinical application await further research.

The Counterproductive Effect of Right Anodal/Left Cathodal Transcranial Direct Current Stimulation Over the Dorsolateral Prefrontal Cortex on Impulsivity in Methamphetamine Addicts

The current study aimed to evaluate the effect of transcranial direct current stimulation (tDCS) over the dorsolateral prefrontal cortex (DLPFC) on behavioral impulsivity in methamphetamine addicts. Forty-five methamphetamine addicts were recruited and randomly divided into active tDCS and sham tDCS groups to receive a daily tDCS intervention for 5 days, with the intensity set to 2 mA for the active group and 0 mA for the sham group. Anodal and cathodal electrodes were, respectively, placed over the right and left DLPFC. Behavioral impulsivity in methamphetamine addicts was examined by the 2-choice oddball task at 3-time points: before tDCS intervention (baseline), after the first intervention (day 1), and after 5 repeated interventions (day 5). Besides, twenty-four healthy male participants were recruited as the healthy controls who completed a 2-choice oddball task. Analysis of accuracy for the 2-choice oddball task showed that behavioral impulsivity was counterproductively increased in the active group, which was shown by the decreased accuracy for the deviant stimulus. The results suggested that the present protocol may not be optimal and other protocols should be considered for the intervention of methamphetamine addicts in the future.

Efficacy of Repetitive Transcranial Magnetic Stimulation in Patients With Methamphetamine Use Disorder: A Systematic Review and Meta-Analysis of Double-Blind Randomized Controlled Trials

BACKGROUND

Repetitive transcranial magnetic stimulation (rTMS) has demonstrated therapeutic potential for treating patients with methamphetamine use disorder (MUD). However, the most effective target and stimulation frequency of rTMS for treating MUD remains unclear. This meta-analysis explored the effect of rTMS on MUD.

METHODS

In this study, PubMed, Cochrane Systematic Reviews, and the Cochrane Collaboration Central Register of Controlled Clinical Trials were searched electronically for double-blind randomized controlled trials that used rTMS for treating MUD. We used published trials to investigate the efficacy of rTMS in MUD up to March 5, 2022, and pooled studies using a random-effect model to compare rTMS treatment effects. Patients who were diagnosed with MUD according to the criteria of the Diagnostic and Statistical Manual of Mental Disorders were recruited. Clinical craving scores between baseline and after rTMS were compared using the standardized mean difference (SMD) with 95% confidence intervals (CIs). The heterogeneity of the included trials was evaluated through a visual inspection of funnel plots and the I² statistic.

RESULTS

We identified seven trials with 462 participants with MUD that met the inclusion criteria. All the studies evaluated craving scores, with rTMS demonstrating a more significant effect than the sham treatment on reducing craving scores (SMD = 0.983, CI = 0.620-1.345, p ≤ 0.001). A subgroup meta-analysis revealed that intermittent theta-burst stimulation (iTBS) had a greater positive effect than 10-Hz rTMS. A metaregression revealed that the SMDs increased with the increase in baseline craving scores, whereas they decreased with the increase in the proportion of men and duration of abstinence.

CONCLUSION

The meta-analysis suggests that rTMS may be associated with treatment effect on craving symptoms in patients with MUD. iTBS may have a greater positive effect on craving reduction than 10-z rTMS.

Deep Brain Stimulation in Drug Addiction Treatment: Research Progress and Perspective

Drug addiction is a chronic psychiatric disorder characterized by compulsive drug-seeking and drug-using behavior, and a tremendous socioeconomic burden to society. Current pharmacological and psychosocial methods have shown limited treatment effects for substance abuse. Deep Brain Stimulation (DBS) is a novel treatment for psychiatric disease and has gradually gained popularity in the treatment of addiction. Addiction is characterized by neuroplastic changes in the nucleus accumbens (NAc), a key structure in the brain reward system, and DBS in this region has shown promising treatment effects. In this paper, the research progress on DBS for drug addiction has been reviewed. Specifically, we discuss the mechanism of NAc DBS for addiction treatment and summarize the results of clinical trials on DBS treatment for addiction to psychoactive substances such as nicotine, alcohol, cocaine, opioids and methamphetamine/amphetamine. In addition, the treatment effects of DBS in other brain regions, such as the substantia nigra pars reticulata (SNr) and insula are discussed.

Alteration of Behavioral Inhibitory Control in High-Altitude Immigrants

Behavioral inhibitory control (BIC) acts as a key cognitive ability, which is essential for humans to withhold inappropriate behaviors. Meanwhile, many studies reported that long-term exposure to high altitude (HA) may affect cognitive ability. However, it is not clear whether long-term exposure to HAs may affect the BIC of an individual. To clarify the role of altitude in the behavioral control of adults and the underlying neural mechanism, we explored the BIC neural activity profiles of healthy immigrants from low-altitude (LA) regions to HA regions. Combining a two-choice oddball paradigm and electrophysiological techniques, this study monitored the N2 and P3 event-related components and neural oscillations across LA and HA groups. Results showed longer reaction times (RTs) for the HA group than the LA group. Relative to the LA group, lower N2 and P3 amplitudes were observed for the HA group. Significant positive correlations were also found between P3 amplitude and theta/delta band power across both groups. Importantly, lower theta/delta band powers were only observed for the HA group under the deviant condition. Collectively, these findings suggest that long-term exposure to HAs may attenuate BIC during the response inhibition stage and provide valuable insights into the neurocognitive implications of environmental altitude on BIC.

Noninvasive brain stimulation of addiction: one target for all?

Noninvasive brain stimulation includes repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS), and emerges as a prospective approach for addiction treatment in clinical practices. The dorsolateral prefrontal cortex (DLPFC) is regarded as the most effective stimulation target, giving its important position in controlling cue-elicited drug craving and initiating drug abuse. In this paper, through literature searches (e.g. Pubmed, Google Scholar), 34 studies (2003-2021) were identified examining the effect of rTMS, tDCS on cravings, and consumption of substance use disorders, including tobacco, alcohol, opioids, and stimulants. We summarize the main methods, designs, and effects of rTMS or tDCS that are delivered to the DLPFC on different types of addiction. We conclude that targeting DLPFC might be effective for all types of drug addiction.

Repetitive Transcranial Magnetic Stimulation: A Potential Treatment for Obesity in Patients with Schizophrenia

Obesity is highly prevalent in patients with schizophrenia and, in association with metabolic syndrome, contributes to premature deaths of patients due to cardiovascular disease complications. Moreover, pharmacologic, and behavioral interventions have not stemmed the tide of obesity in schizophrenia. Therefore, novel effective interventions are urgently needed. Repetitive transcranial magnetic stimulation (rTMS) has shown efficacy for inducing weight loss in obese non-psychiatric samples but this promising intervention has not been evaluated as a weight loss intervention in patients with schizophrenia. In this narrative review, we describe three brain mechanisms (hypothalamic inflammation, dysregulated mesocorticolimbic reward system, and impaired prefrontal cortex function) implicated in the pathogenesis and pathophysiology of obesity and emphasize how the three mechanisms have also been implicated in the neurobiology of schizophrenia. We then argue that, based on the three overlapping brain mechanisms in obesity and schizophrenia, rTMS would be effective as a weight loss intervention in patients with schizophrenia and comorbid obesity. We end this review by describing how deep TMS, relative to conventional TMS, could potentially result in larger effect size for weight loss. While this review is mainly conceptual and based on an extrapolation of findings from non-schizophrenia samples, our aim is to stimulate research in the use of rTMS for weight loss in patients with schizophrenia.

Add-on repetitive transcranial magnetic stimulation in patients with opioid use disorder undergoing methadone maintenance therapy

Background: Repetitive transcranial magnetic stimulation (rTMS) shows potential therapeutic effects for individuals with addiction, but few studies have examined individuals with opioid use disorder (OUD).Objectives: We conducted an add-on double-blinded, sham-controlled rTMS feasibility pilot trial to examine OUD participants undergoing methadone maintenance therapy (MMT). The current report focused on the effects of rTMS on (1) craving and heroin use behavior and (2) depression, impulsivity, and attention.Methods: Active or sham rTMS treatment was applied to the left dorsolateral prefrontal cortex (DLPFC) over a total of 11 sessions in 4 weeks (15-Hz frequency, 4 seconds per train, intertrain interval of 26 seconds, 40 trains per session) in OUD participants (ClinicalTrials.gov registration number: NCT03229642). Craving, heroin use severity, urine morphine tests, the Hamilton Depression Rating Scale (HDRS), the Barratt Impulsiveness Scale-11 (BIS-11), and the Continuous Performance Tests (CPTs) were measured.Results: Twenty-two OUD participants were enrolled, of which eleven (8 males) were undergoing active rTMS and nine (8 males) were in the sham rTMS group. After 12 weeks of follow-up, the active rTMS group did not show significantly greater improvements than the sham group with respect to craving, heroin use, or urine morphine test results. However, HDRS scores, BIS-11 attentional subscales, and CPTs commission T-scores (C-TS) were significantly lower in the active rTMS group (P = .003, 0.04, and 0.02, respectively) than in the sham group.Conclusion: Add-on rTMS did not appear to improve heroin use behavior but may have benefitted depressive symptoms, impulse control and attention in OUD participants undergoing MMT.

Impulse Inhibition Ability With Methamphetamine Dependents Varies at Different Abstinence Stages

Objective: The purpose of this study is to evaluate whether the impulse inhibition ability with methamphetamine dependents would vary at different abstinence stages. Methods: Sixty-three methamphetamine dependents, including 31 short-term (< 10 months) and 32 long-term (≥ 10 months) abstinence participants, were recruited for this study. In addition, 33 men were recruited as the healthy control (HC) group. All participants performed a two-choice oddball task, which is well-established to assess impulse inhibition. Accuracy for deviant trials and deviant-standard reaction time (RT) delay were computed as indexes of impulse inhibition. Results: The accuracy for deviant trials was significantly decreased in short-term abstinence subjects (90.61%) compared to HC subjects (95.42%, p < 0.01), which was coupled with a shorter RT delay reflecting greater impulsivity in the short-term group vs. the HC group (47 vs. 73 ms, p < 0.01). However, impulse inhibition was improved in the long-term group, shown by the increased accuracy for deviant trials in the long-term group compared to the short-term group (94.28 vs. 90.61%, p < 0.05) and the similar accuracy for the long-term and HC groups (p > 0.05). Further regression analyses confirmed that the abstinence duration positively predicted impulse inhibition of methamphetamine dependents, both in accuracy and RT for deviant stimulus (β = 0.294, p = 0.019; β = 0.337, p = 0.007). Conclusion: These results suggest that long-term abstinence is more effective in improving impulse inhibition with methamphetamine dependents.

Predictive Role of Executive Function in the Efficacy of Intermittent Theta Burst Transcranial Magnetic Stimulation Modalities for Treating Methamphetamine Use Disorder-A Randomized Clinical Trial

Background: Repetitive transcranial magnetic stimulation (rTMS) has therapeutic effects on craving in methamphetamine (METH) use disorder (MUD). The chronic abuse of METH causes impairments in executive function, and improving executive function reduces relapse and improves treatment outcomes for drug use disorder. The purpose of this study was to determine whether executive function helped predict patients' responses to rTMS treatment. Methods: This study employed intermittent theta burst stimulation (iTBS) rTMS modalities and observed their therapeutic effects on executive function and craving in MUD patients. MUD patients from an isolated Drug Rehabilitation Institute in China were chosen and randomly allocated to the iTBS group and sham-stimulation group. All participants underwent the Behavior Rating Inventory of Executive Function - Adult Version Scale (BRIEF-A) and Visual Analog Scales (VAS) measurements. Sixty-five healthy adults matched to the general condition of MUD patients were also recruited as healthy controls. Findings: Patients with MUD had significantly worse executive function. iTBS groups had better treatment effects on the MUD group than the sham-stimulation group. Further Spearman rank correlation and stepwise multivariate regression analysis revealed that reduction rates of the total score of the BRIEF-A and subscale scores of the inhibition factor and working memory factor in the iTBS group positively correlated with improvements in craving. ROC curve analysis showed that working memory (AUC = 87.4%; 95% CI = 0.220, 0.631) and GEC (AUC = 0.761%; 95% CI = 0.209, 0.659) had predictive power to iTBS therapeutic efficacy. The cutoff values are 13.393 and 59.804, respectively. Conclusions: The iTBS rTMS had a better therapeutic effect on the executive function of patients with MUD, and the improved executive function had the potential to become a predictor for the efficacy of iTBS modality for MUD treatment. Clinical Trial Registration: ClinicalTrials.gov, identifier: ChiCTR2100046954.