A coordinate-based meta-analysis of white matter alterations in patients with alcohol use disorder

Alcohol-Induced Changes in Brain Microstructure: Uncovering Novel Pathophysiological Mechanisms of AUD Using Translational DTI in Humans and Rodents

Alcohol use disorder (AUD) induces significant structural alterations in both gray and white matter, contributing to cognitive and functional impairments. This chapter presents a translational neuroimaging approach using diffusion-weighted MRI in humans and rodents to uncover novel pathophysiological mechanisms underlying AUD. Our studies demonstrate that increased mean diffusivity (MD) in gray matter reflects microglial reactivity and reduced extracellular space tortuosity, leading to enhanced volume neurotransmission. In white matter, fractional anisotropy (FA) reductions indicate progressive deterioration of key tracts, particularly the fimbria/fornix, linked to impaired cognitive flexibility. Importantly, longitudinal analyses reveal that white matter degeneration continues during early abstinence, suggesting that neuroinflammation and demyelination persist beyond alcohol cessation. Finally, we discuss how neuromodulatory interventions, such as transcranial magnetic stimulation (TMS), may promote recovery by enhancing myelin plasticity. These findings provide crucial insights into AUD's neurobiological underpinnings and highlight potential therapeutic targets for improving treatment outcomes.

Neural correlates of executive dysfunction in alcohol use disorder: preliminary evidence from 18F-FDG-PET

Neuroimaging studies have shown that cognitive impairments in Alcohol Use Disorder (AUD), particularly involving executive functions, reflect widespread structural and functional brain alterations. However, these findings mostly result from magnetic resonance imaging (MRI). To complement previous MRI findings with a more direct measure of brain metabolism, we therefore explored the neural bases of executive impairments in AUD using FDG-PET. Twenty-three AUD patients and 18 healthy controls underwent a neurocognitive assessment, and patients also an 18F-FDG-PET scan. Using as reference for brain metabolism a FDG-PET dataset of age-matched healthy controls, we assessed a relationship between executive impairment and regional hypometabolism in AUD patients, while also considering a possible moderating age effect. Compared with controls, AUD patients exhibited widespread hypometabolism in the anterior/midcingulate cortex, fronto-insular cortex, and medial precuneus, supporting the hypothesis that their impaired executive performance might reflect an altered transition from automatic to controlled processing. Patients' worse executive performance reflected in higher metabolism in the midcingulate cortex and medial precuneus, suggesting a possible compensatory neural mechanism. This relationship was moderated by age in the right anterior insula, where the decrease of metabolism is steeper, in older patients, at the lowest level of cognitive performance. This finding suggests that an age-related decrease in the compensatory capacity of the insular node of the salience network might contribute to cognitive decline in older patients. While supporting the use of FDG-PET to improve the understanding of AUD-related cognitive decline, and differential diagnosis in older patients, these findings might help design personalized innovative treatment protocols.

Demyelination in psychiatric and neurological disorders: Mechanisms, clinical impact, and novel therapeutic strategies

Demyelination, defined as the loss of myelin sheaths around neuronal axons, is increasingly recognized as a key factor in a broad range of psychiatric and neurological disorders, including schizophrenia, major depressive disorder, bipolar disorder, post-traumatic stress disorder, autism spectrum disorder, substance use disorders, Alzheimer's disease, Parkinson's disease, and multiple sclerosis. This review investigates the core mechanisms driving demyelination, its clinical impact, and emerging therapeutic strategies aimed at maintaining or restoring myelin integrity. Disruption of myelin impairs crucial neural communication pathways, resulting in cognitive, motor, and behavioral deficits that substantially reduce quality of life and create significant economic and social challenges. Key contributors to demyelination include genetic predisposition, environmental triggers, immune dysregulation, neuroinflammation, and alterations in the gut-brain axis mediated by the vagus nerve. Promising therapies include sphingosine 1-phosphate receptor modulators and muscarinic acetylcholine receptor antagonists, both of which diminish immune-related myelin damage and may enhance neuroprotection. In addition, the novel antidepressant arketamine appears to boost myelination through transforming growth factor-β1 signaling pathways. Approaches targeting the gut-brain axis, such as noninvasive transcutaneous auricular vagus nerve stimulation and fecal microbiota transplantation, may also help reduce inflammation and support myelin repair. Future research should center on clarifying the precise molecular mechanisms of demyelination, developing targeted therapies, and leveraging advanced neuroimaging for earlier detection and personalized treatment. By combining immunomodulatory and neuroprotective strategies, there is potential to significantly improve outcomes for individuals affected by demyelinating psychiatric and neurological disorders.

Interactions between overweight/obesity and alcohol dependence impact human brain white matter microstructure: evidence from DTI

There is inconsistent evidence for an association of obesity with white matter microstructural alterations. Such inconsistent findings may be related to the cumulative effects of obesity and alcohol dependence. This study aimed to investigate the possible interactions between alcohol dependence and overweight/obesity on white matter microstructure in the human brain. A total of 60 inpatients with alcohol dependence during early abstinence (44 normal weight and 16 overweight/obese) and 65 controls (42 normal weight and 23 overweight/obese) were included. The diffusion tensor imaging (DTI) measures [fractional anisotropy (FA) and radial diffusivity (RD)] of the white matter microstructure were compared between groups. We observed significant interactive effects between alcohol dependence and overweight/obesity on DTI measures in several tracts. The DTI measures were not significantly different between the overweight/obese and normal-weight groups (although widespread trends of increased FA and decreased RD were observed) among controls. However, among the alcohol-dependent patients, the overweight/obese group had widespread reductions in FA and widespread increases in RD, most of which significantly differed from the normal-weight group; among those with overweight/obesity, the alcohol-dependent group had widespread reductions in FA and widespread increases in RD, most of which were significantly different from the control group. This study found significant interactive effects between overweight/obesity and alcohol dependence on white matter microstructure, indicating that these two controllable factors may synergistically impact white matter microstructure and disrupt structural connectivity in the human brain.

Sex-based Influences on White Matter Tract Integrity in Alcohol Use Disorder: a Systematic Review

Purpose of the Review

Women experience worse alcohol-related health consequences compared to men, including greater risk and susceptibility to the neurotoxic effects of alcohol. There is a critical need to identify underlying neurobiological mechanisms underlying sex differences in alcohol use disorder (AUD) phenotypes to better inform individualized treatment options. This report aimed to systematically review existing original literature that examined sex differences in white matter tract integrity in individuals with heavy drinking/AUD using diffusion magnetic resonance imaging (dMRI) and provide recommendations for future research. A systematic review was conducted using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and PubMed and Google Scholar databases from inception until January 1, 2024.

Recent Findings

Of 565 studies from the database search, 12 met study criteria. Nine (75%) showed evidence of sex-related differences in white matter tract integrity. Five studies showed greater vulnerability of white matter tract degradation in women with heavy drinking/AUD and four showed greater vulnerability in men with heavy drinking/AUD.

Summary

This is the first study to systematically assess the existing literature on sex differences in AUD-related white matter tract integrity. The findings from this systematic review were equivocal. Future research should address the mixed literature by systematically examining sex differences in white matter tract integrity in larger, well-characterized samples to account for confounding factors such as alcohol use history, age, other substance use, and psychiatric comorbidities.

Remission from addiction: erasing the wrong circuits or making new ones?

Chronic relapse is a hallmark of substance-use disorders (SUDs), but many people with SUDs do recover and eventually enter remission. Many preclinical studies in this field aim to identify interventions that can precipitate recovery by reversing or erasing the neuronal circuit changes caused by chronic drug use. A better understanding of remission from SUDs can also come from preclinical studies that model factors known to influence recovery in humans, such as the negative consequences of drug use and positive environmental influences. In this Perspective we discuss human neuroimaging studies that have provided information about recovery from SUDs and highlight mechanisms identified in preclinical studies - such as the reconfiguration of neuronal circuits - that could contribute to remission. We also analyse how studies of memory and forgetting can provide insights into the mechanisms of remission. Overall, we propose that remission can be driven by the introduction of new neuronal changes (which outcompete those induced by drugs) as well as by the erasure of drug-induced changes.

Compensation patterns and altered functional connectivity in alcohol use disorder with and without Korsakoff's syndrome

Alcohol use disorder is a chronic disease characterized by an inappropriate pattern of drinking, resulting in negative consequences for the individual's physical, mental and social health. Korsakoff's syndrome is a complication of alcohol use disorder and is characterized by severe memory and executive deficits. The fronto-cerebellar and Papez circuits are structurally affected in patients with alcohol use disorder with and without Korsakoff's syndrome. The first objective of the present study was to measure the effect of chronic and excessive alcohol consumption on resting-state functional connectivity of these two functional brain networks. The second objective was to identify, for the first time, resting-state functional connectivity abnormalities specific to amnesic patients with Korsakoff's syndrome. In the present study, a neuropsychological assessment and a resting-state functional magnetic resonance imaging examination were conducted in 31 healthy controls (43.6 ± 6.1 years) and 46 patients (46.6 ± 9.1 years) with alcohol use disorder including 14 patients with Korsakoff's syndrome (55.5 ± 5.3 years) to examine the effect of chronic and heavy alcohol consumption on functional connectivity of the fronto-cerebellar and the Papez circuits at rest and the specificity of functional connectivity changes in Korsakoff's syndrome compared to alcohol use disorder without Korsakoff's syndrome. The resting-state functional connectivity analyses focused on the nodes of the fronto-cerebellar and Papez circuits and combined region of interest and graph theory approaches, and whether these alterations are associated with the neuropsychological profile. In patients pooled together compared to controls, lower global efficiency was observed in the fronto-cerebellar circuit. In addition, certain regions of the fronto-cerebellar and Papez circuits were functionally hyperconnected at rest, which positively correlated with executive functions. Patients with Korsakoff's syndrome showed lower resting-state functional connectivity, lower local and global efficiency within the Papez circuit compared to those without Korsakoff's syndrome. Resting-state functional connectivity positively correlated with several cognitive scores in patients with Korsakoff's syndrome. The fronto-cerebellar and Papez circuits, two normally well-segregated networks, are functionally altered by alcohol use disorder. The Papez circuit attempts to compensate for deficits in the fronto-cerebellar circuit, albeit insufficiently as evidenced by patients' overall lower cognitive performance. Korsakoff's syndrome is characterized by altered functional connectivity in the Papez circuit known to be centrally involved in memory.

Neuroimaging Biomarkers in Addiction

As a neurobiological process, addiction involves pathological patterns of engagement with substances and a range of behaviors with a chronic and relapsing course. Neuroimaging technologies assess brain activity, structure, physiology, and metabolism at scales ranging from neurotransmitter receptors to large-scale brain networks, providing unique windows into the core neural processes implicated in substance use disorders. Identified aberrations in the neural substrates of reward and salience processing, response inhibition, interoception, and executive functions with neuroimaging can inform the development of pharmacological, neuromodulatory, and psychotherapeutic interventions to modulate the disordered neurobiology. Based on our systematic search, 409 protocols registered on ClinicalTrials.gov include the use of one or more neuroimaging paradigms as an outcome measure in addiction, with the majority (N=268) employing functional magnetic resonance imaging (fMRI), followed by positron emission tomography (PET) (N=71), electroencephalography (EEG) (N=50), structural magnetic resonance imaging (MRI) (N=35) and magnetic resonance spectroscopy (MRS) (N=35). Furthermore, in a PubMed systematic review, we identified 61 meta-analyses including 30 fMRI, 22 structural MRI, 8 EEG, 7 PET, and 3 MRS meta-analyses suggesting potential biomarkers in addictions. These studies can facilitate the development of a range of biomarkers that may prove useful in the arsenal of addiction treatments in the coming years. There is evidence that these markers of large-scale brain structure and activity may indicate vulnerability or separate disease subtypes, predict response to treatment, or provide objective measures of treatment response or recovery. Neuroimaging biomarkers can also suggest novel targets for interventions. Closed or open loop interventions can integrate these biomarkers with neuromodulation in real-time or offline to personalize stimulation parameters and deliver the precise intervention. This review provides an overview of neuroimaging modalities in addiction, potential neuroimaging biomarkers, and their physiologic and clinical relevance. Future directions and challenges in bringing these putative biomarkers from the bench to the bedside are also discussed.

Binge drinking and progression of white matter hyperintensities of presumed vascular origin in older men

BACKGROUND

Information on trajectories of diffuse subcortical brain damage of vascular origin associated with binge drinking in older adults is limited. We sought to evaluate the impact of this drinking pattern on the progression of white matter hyperintensities (WMH) of presumed vascular origin in individuals aged ≥60 years taken from the community.

METHODS

Following a longitudinal prospective design, participants of the Atahualpa Project Cohort received interviews to assess patterns of alcohol intake as well as baseline and follow-up brain MRIs. Only men were included because alcohol consumption in women is negligible and tend not to engage in binge drinking in our studied population. Poisson regression models were fitted to assess the incidence rate ratio of WMH progression by patterns of alcohol use (binge drinking or not), after adjusting for demographics, level of education and cardiovascular risk factors.

RESULTS

The study included 114 men aged ≥60 years (mean age: 65.1±5.4 years). Thirty-seven participants (32%) reported binge drinking for more than 30 years. Follow-up MRIs revealed WMH progression in 45 participants (39%) after a median of 7.2 years. In unadjusted analysis, the risk of WMH progression among individuals with binge drinking was 2.08 (95% C.I.: 1.16-3.73). After adjustment for age, education level and vascular risk factors, participants with this drinking pattern were 2.75 times (95% C.I.: 1.42-5.30) more likely to have WMH progression than those who did not.

CONCLUSIONS

Study results show an independent association between binge drinking and WMH progression in community-dwelling older men.

Role of the Microbiome and the Gut-Brain Axis in Alcohol Use Disorder: Potential Implication for Treatment Development

The gut microbiota is constituted by trillions of microorganisms colonizing the human intestine. Studies conducted in patients with alcohol use disorder (AUD) have shown altered microbial composition related to bacteria, viruses, and fungi.This review describes the communication pathways between the gut and the brain, including the ones related to the bacterial metabolites, the inflammatory cytokines, and the vagus nerve. We described in more detail the gut-derived metabolites that have been shown to be implicated in AUD or that could potentially be involved in the development of AUD due to their immune and/or neuroactive properties, including tryptophan-derivatives, tyrosine-derivatives, short chain fatty acids.Finally, we discussed the potential beneficial effects of microbiome-based therapies for AUD such as probiotics, prebiotics, postbiotic, and phage therapy.

Psychosis superspectrum II: neurobiology, treatment, and implications

Alternatives to traditional categorical diagnoses have been proposed to improve the validity and utility of psychiatric nosology. This paper continues the companion review of an alternative model, the psychosis superspectrum of the Hierarchical Taxonomy of Psychopathology (HiTOP). The superspectrum model aims to describe psychosis-related psychopathology according to data on distributions and associations among signs and symptoms. The superspectrum includes psychoticism and detachment spectra as well as narrow subdimensions within them. Auxiliary domains of cognitive deficit and functional impairment complete the psychopathology profile. The current paper reviews evidence on this model from neurobiology, treatment response, clinical utility, and measure development. Neurobiology research suggests that psychopathology included in the superspectrum shows similar patterns of neural alterations. Treatment response often mirrors the hierarchy of the superspectrum with some treatments being efficacious for psychoticism, others for detachment, and others for a specific subdimension. Compared to traditional diagnostic systems, the quantitative nosology shows an approximately 2-fold increase in reliability, explanatory power, and prognostic accuracy. Clinicians consistently report that the quantitative nosology has more utility than traditional diagnoses, but studies of patients with frank psychosis are currently lacking. Validated measures are available to implement the superspectrum model in practice. The dimensional conceptualization of psychosis-related psychopathology has implications for research, clinical practice, and public health programs. For example, it encourages use of the cohort study design (rather than case-control), transdiagnostic treatment strategies, and selective prevention based on subclinical symptoms. These approaches are already used in the field, and the superspectrum provides further impetus and guidance for their implementation. Existing knowledge on this model is substantial, but significant gaps remain. We identify outstanding questions and propose testable hypotheses to guide further research. Overall, we predict that the more informative, reliable, and valid characterization of psychopathology offered by the superspectrum model will facilitate progress in research and clinical care.

Structural and functional brain alterations in subthreshold depression: A multimodal coordinate-based meta-analysis

Imaging studies of subthreshold depression (StD) have reported structural and functional abnormalities in a variety of spatially diverse brain regions. However, there is no consensus among different studies. In the present study, we applied a multimodal meta-analytic approach, the Activation Likelihood Estimation (ALE), to test the hypothesis that StD exhibits spatially convergent structural and functional brain abnormalities compared to healthy controls. A total of 31 articles with 25 experiments were included, collectively representing 1001 subjects with StD. We found consistent differences between StD and healthy controls mainly in the left insula across studies with various neuroimaging methods. Further exploratory analyses found structural atrophy and decreased functional activities in the right pallidum and thalamus in StD, and abnormal spontaneous activity converged to the middle frontal gyrus. Coordinate-based meta-analysis found spatially convergent structural and functional impairments in StD. These findings provide novel insights for understanding the neural underpinnings of subthreshold depression and enlighten the potential targets for its early screening and therapeutic interventions in the future.

Disrupted white matter structural networks in individuals with alcohol dependence

Previous diffusion tensor imaging (DTI) studies have demonstrated widespread white matter microstructure damage in individuals with alcoholism. However, very little is known about the alterations in the topological architecture of white matter structural networks in alcohol dependence (AD). This study included 67 AD patients and 69 controls. The graph theoretical analysis method was applied to examine the topological organization of the white matter structural networks, and network-based statistics (NBS) were employed to detect structural connectivity alterations. Compared to controls, AD patients exhibited abnormal global network properties characterized by increased small-worldness, normalized clustering coefficient, clustering coefficient, and shortest path length; and decreased global efficiency and local efficiency. Further analyses revealed decreased nodal efficiency and degree centrality in AD patients mainly located in the default mode network (DMN), including the precuneus, anterior cingulate and paracingulate gyrus, median cingulate and paracingulate gyrus, posterior cingulate gyrus, and medial part of the superior frontal gyrus. Furthermore, based on NBS approaches, patients displayed weaker subnetwork connectivity mainly located in the region of the DMN. Additionally, altered network metrics were correlated with intelligence quotient (IQ) scores and global assessment function (GAF) scores. Our results may reveal the disruption of whole-brain white matter structural networks in AD individuals, which may contribute to our comprehension of the underlying pathophysiological mechanisms of alcohol addiction at the level of white matter structural networks.

Brain volumes in alcohol use disorder: Do females and males differ? A whole-brain magnetic resonance imaging mega-analysis

Emerging evidence suggests distinct neurobiological correlates of alcohol use disorder (AUD) between sexes, which however remain largely unexplored. This work from ENIGMA Addiction Working Group aimed to characterize the sex differences in gray matter (GM) and white matter (WM) correlates of AUD using a whole-brain, voxel-based, multi-tissue mega-analytic approach, thereby extending our recent surface-based region of interest findings on a nearly matching sample using a complementary methodological approach. T1-weighted magnetic resonance imaging (MRI) data from 653 people with AUD and 326 controls was analyzed using voxel-based morphometry. The effects of group, sex, group-by-sex, and substance use severity in AUD on brain volumes were assessed using General Linear Models. Individuals with AUD relative to controls had lower GM volume in striatal, thalamic, cerebellar, and widespread cortical clusters. Group-by-sex effects were found in cerebellar GM and WM volumes, which were more affected by AUD in females than males. Smaller group-by-sex effects were also found in frontotemporal WM tracts, which were more affected in AUD females, and in temporo-occipital and midcingulate GM volumes, which were more affected in AUD males. AUD females but not males showed a negative association between monthly drinks and precentral GM volume. Our results suggest that AUD is associated with both shared and distinct widespread effects on GM and WM volumes in females and males. This evidence advances our previous region of interest knowledge, supporting the usefulness of adopting an exploratory perspective and the need to include sex as a relevant moderator variable in AUD.

Understanding the Mechanisms of Action and Effects of Drugs of Abuse

AIM

Drug abuse and addiction are major public health concerns, with millions of people worldwide affected by the negative consequences of drug use. To better understand this complex issue, a review was conducted to examine the mechanisms of action and effects of drugs of abuse, including their acute and chronic effects, the symptoms of abstinence syndrome, as well as their cardiovascular impacts.

METHODS

The analyzed data were obtained after surveying an electronic database, namely PubMed, with no time limit, grey literature sources, and reference lists of relevant articles.

RESULTS

The review highlights the different categories of drugs of abuse, such as opioids, stimulants, depressants, hallucinogens, and cannabis, and discusses the specific ways that each drug affects the brain and body. Additionally, the review explores the short-term and long-term effects of drug abuse on the body and mind, including changes in brain structure and function, physical health problems, and mental health issues, such as depression and anxiety. In addition, the review explores the effects of drug abuse on cardiovascular health, focusing on electrocardiogram changes. Moreover, the analysis of relevant literature also highlighted possible genetic susceptibility in various addictions. Furthermore, the review delves into the withdrawal symptoms that occur when someone stops using drugs of abuse after a period of chronic use.

CONCLUSION

Overall, this review provides a comprehensive overview of the current state of knowledge on drug abuse and addiction. The findings of this review can inform the development of evidence-based prevention and intervention strategies to address this critical public health issue.

Alcohol use disorder: Neuroimaging evidence for accelerated aging of brain morphology and hypothesized contribution to age-related dementia

Excessive alcohol use curtails longevity by rendering intoxicated individuals vulnerable to heightened risk from accidents, violence, and alcohol poisoning, and makes chronically heavy drinkers vulnerable to acceleration of age-related medical and psychiatric conditions that can be life threatening (Yoon, Chen, Slater, Jung, & White, 2020). Thus, studies of factors influencing age-alcohol interactions must consider the potential that the alcohol use disorder (AUD) population may not represent the oldest ages of the unaffected population and may well have accrued comorbidities associated with both AUD and aging itself. Herein, we focus on the aging of the brains of men and women with AUD, keeping AUD contextual factors in mind. Knowledge of the potential influence of the AUD-associated co-factors on the condition of brain structure may lead to identifying modifiable risk factors to avert physical declines and may reverse or arrest further AUD-related degradation of the brain. In this narrative review, we 1) describe quantitative, controlled studies of brain macrostructure and microstructure of adults with AUD, 2) consider the possibility of recovery of brain integrity through harm reduction with sustained abstinence or reduced drinking, and 3) speculate on the ramifications of accelerated aging in AUD as contributing to age-related dementia.

Effects of white matter lesion grading on the cognitive function of patients with chronic alcohol dependence

BACKGROUND

Alcohol dependence has become a major problem that poses a serious threat to public health. Long-term heavy alcohol consumption can lead to brain functional disorders. This study aimed to investigate the relationship of the severity of cerebral white matter lesions (WMLs), serum neurofilament light (NfL) and inflammatory factors, tumour necrosis factor alpha (TNF-α) and Interleukin-1β (IL-1β), with the cognitive function of patients with alcohol dependence.

METHODS

A total of 118 patients were enrolled in this prospective study, and divided into alcohol-dependent and non-alcohol-dependent groups. The severity of WMLs was assessed using the Fazekas scale based on magnetic resonance imaging analysis. The expression levels of NfL, TNF-α and IL-1β in the serum of the subjects were measured by enzyme-linked immunosorbent assay. The cognitive function and psychological status of the patients were assessed using the Minimum Mental State Examination (MMSE), Montreal Cognitive Assessment (MoCA), Hamilton Depression Rating Scale (HAMD) and Hamilton Anxiety Rating Scale (HAMA). The severity of WMLs and the expression levels of serum NfL, TNF-α and IL-1β in alcohol-dependent patients were analysed for their influence on cognitive function. This clinical trial was approved by China Clinical Trials Registry, and the trial number is ChiCTR2200066057 (http://www.chictr.org.cn/searchproj.aspx).

RESULTS

The score of Fazekas scale was higher, and the MMSE score and MoCA score were lower in the alcohol-dependent group than those in the non-alcohol-dependent group. Moreover, the Fazekas score of the alcohol-dependent group was negatively correlated with the MMSE and MoCA scores. The serum NfL, TNF-α and IL-1β levels were higher in the alcohol-dependent group than in the non-alcohol-dependent group, and the serum NfL, TNF-α and IL-1β levels in the alcohol-dependent group were negatively correlated with the MMSE and MoCA scores.

CONCLUSION

Alcohol-dependent patients have more severe cerebral WMLs and significant cognitive impairment, particularly in visuospatial and executive functions, attention, calculation, abstraction, delayed recall and orientation. Serum NfL, TNF-α and IL-1β may be used as biomarkers to assess alcohol related cognitive decline.

Advances in neuroimaging studies of alcohol use disorder (AUD)

Alcohol use disorder (AUD) is a worldwide problem and the most common substance use disorder. Chronic alcohol consumption may have negative effects on the body, the mind, the family, and even society. With the progress of current neuroimaging methods, an increasing number of imaging techniques are being used to objectively detect brain impairment induced by alcoholism and serve a vital role in the diagnosis, prognosis, and treatment assessment of AUD. This article organizes and analyzes the research on alcohol dependence concerning the main noninvasive neuroimaging methods, structural magnetic resonance imaging, functional magnetic resonance imaging, and electroencephalography, as well as the most common noninvasive brain stimulation - transcranial magnetic stimulation, and intersperses the article with joint intra- and intergroup studies, providing an outlook on future research directions.

Alterations in white matter microstructure in alcohol and alcohol‐polydrug dependence: Associations with lifetime alcohol and nicotine exposure

Evidence suggests that alcohol dependence (AD) is associated with microstructural deficits in white matter, but the relationship with lifetime alcohol exposure and the impact of polydrug dependence is not well understood. Using diffusion tensor magnetic resonance (MR) imaging, we examined white matter microstructure in relation to alcohol and polydrug dependence using data from the Imperial College Cambridge Manchester (ICCAM) platform study. Tract‐based spatial statistics were used to examine fractional anisotropy (FA) in a cohort of abstinent AD participants, most of whom had a lifetime history of dependence to nicotine. A further subgroup also had a lifetime history of dependence to cocaine and/or opiates. Individuals with AD had lower FA throughout the corpus callosum, and negative associations with alcohol and nicotine exposure were found. A group‐by‐age interaction effect was found showing greater reductions with age in the alcohol‐dependent group within corpus callosum, overlapping with the group difference. We found no evidence of recovery with abstinence. A comparison of alcohol‐only‐ and alcohol‐polydrug‐dependent groups found no differences in FA. Overall, our findings show that AD is associated with lower FA and suggest that these alterations are primarily driven by lifetime alcohol consumption and cigarette smoking, showing no relationship with exposure to other substances such as cocaine, opiates or cannabis. Reductions in FA across the adult lifespan are more pronounced in AD and offer further support for the notion of accelerated ageing in relation to alcohol dependence. These findings highlight there may be lasting structural differences in white matter in alcohol dependence, despite continued abstinence.

Association between white matter microstructure and cognitive function in patients with methamphetamine use disorder

Methamphetamine use disorder (MUD) has been associated with broad neurocognitive impairments. While the cognitive impairments of MUD have been demonstrated, the neuropathological underpinnings remain inadequately understood. To date, the published human diffusion tensor imaging (DTI) studies involving the correlation between diffusion parameters and neurocognitive function in MUD are limited. Hence, the present study aimed to examine the association between cognitive performance and white matter microstructure in patients with MUD. Forty-five patients with MUD and 43 healthy controls (HCs) completed their demographic information collection, cognitive assessments, and DTI imaging. DTI images were preprocessed to extract fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD) of various fiber tracts. Univariate tests were used to examine group differences in cognitive assessments and DTI metrics. Linear regression was used to examine the relationship between these two metrics. The results revealed that patients with MUD had lower subset scores of the MATRICS Consensus Cognitive Battery (MCCB), which reflects five cognitive domains: processing speed, attention, verbal learning, visual learning, problem-solving. Patients with MUD also had significantly higher AD, MD, and RD values of the left superior longitudinal fasciculus than HCs. Furthermore, the RD value of the left superior longitudinal fasciculus was a significant predictor of processing speed and problem-solving ability, as shown by the digit-symbol coding test and NAB-Mazes scores, respectively. Findings extended our understanding of white matter microstructure that is related to neurocognitive deficits in MUD and provided potential targets for the prevention and treatment of this chronic disorder.