Alcohol use and interoception - A narrative review

Validity Concerns About the Heartbeat Counting Task Extend to Alcohol Use disorder: Evidence From Subclinical and Clinical Samples

Theoretical models propose that interoception plays a role in addictive disorder. However, this assumption has been mostly tested using the heartbeat counting task (HCT), which is known to be contaminated by estimation strategies. An adapted version of the HCT (in which respondents report only felt heartbeats) has been developed to reduce estimation biases. Here, we examined the validity of the classical and adapted HCT versions in samples presenting alcohol use disorders. We recruited a clinical sample of 48 patients with severe alcohol use disorder (SAUD), matched with 41 healthy controls (HC), and a subclinical sample of 32 binge drinkers (BD), matched with 30 HC. Participants performed the classical HCT, adapted HCT, and a time estimation task. We additionally assessed mental health variables theoretically related to interoception (alexithymia, anxiety, childhood trauma, depression and emotion regulation). In all groups, HCT scores were smaller in adapted than classical HCT. Patients with SAUD, but not BD, showed lower HCT scores than matched controls, independently of the task. We found no correlation between HCT scores and psychological constructs. Heartbeats reported during classical HCT correlated with seconds reported during time estimation task for SAUD and matched HC, suggesting the use of time estimation strategies to perform the task. The largely reduced HCT performance in the adapted version, the association between HCT performance and time estimation performance and the lack of theoretically expected associations between HCT scores and psychological variables extend doubts on the validity of these tasks for measuring interoceptive accuracy in problematic alcohol consumption.

Effects of alcohol and cannabis co-use on salience network resting state functional connectivity in individuals who drink alcohol heavily

INTRODUCTION

The salience network may be linked to addiction. Evidence suggests less salience network resting state functional connectivity (rsFC) from heavy alcohol use, but higher rsFC within and between brain networks from regular cannabis use. Given the rise in alcohol-cannabis co-use, the present study sought to elucidate rsFC between regions within the salience network and regions across the whole brain in individuals who use no drugs regularly, those who use alcohol only heavily, and those who co-use alcohol-cannabis.

METHODS

This is a secondary analysis of three clinical laboratory studies. A total of sixty individuals were classified into one of three groups based on their drug use: control (n = 16), heavy alcohol use only (n = 27), and heavy alcohol and regular cannabis co-use (n = 17). All participants completed resting state fMRI scans. Seed regions from the salience network were used to examine group differences in rsFC.

RESULTS

Main effects of group on rsFC emerged between the anterior cingulate cortex, left and right anterior insula, and left supramarginal gyrus seeds and regions associated with motor, sensory, visual, and executive control functioning (all ps < 0.05). Post-hoc analyses revealed less rsFC between alcohol-only and co-use groups as compared to controls (all ps < 0.05), but no differences between alcohol-only and co-use groups (all ps > 0.05).

CONCLUSIONS

This preliminary study suggests that co-using alcohol-cannabis may not be associated with any additive or contrasting effects on rsFC compared to using alcohol alone. Thus, in individuals who co-use alcohol-cannabis, alcohol may drive neural alterations associated with inhibitory control and substance craving.

The role of interoception in lifestyle factors: A systematic review

BACKGROUND

Interoception, the perception of the internal state of the body, offers an underrepresented and intriguing potential avenue for altering lifestyle-related behaviors. Interoception is intrinsically related to maintaining homeostasis and the flexible allostatic regulation of complex demands. Internal bodily states may also be influenced by lifestyle factors and related problems. This systematic review aimed to provide insight into the current state of evidence about the role of interoception in lifestyle factors.

METHODS

Studies from three databases (PubMed, Embase, and Web of Science) were screened for eligibility based on two inclusion criteria: 1) at least one measure of interoception (e.g., interoceptive accuracy, attention, or awareness), and 2) at least one measure of a lifestyle factor (i.e., alcohol consumption, cognitive leisure and relaxation activities, eating behavior, exercise, sleep, or smoking). Risk of bias was assessed using an adjusted quality score checklist, consisting of five items related to study design, population size, exposure measurement, outcome measurement, and adjustment for confounders.

RESULTS

The review included 73 studies. Out of the included studies, 51 measured interoceptive accuracy and 36 measured interoceptive attention. Six studies quantified interoceptive awareness. In terms of lifestyle factors, 26 studies on cognitive leisure and relaxation activities, 19 studies on eating behavior, 12 studies focused on alcohol consumption, 10 studies on exercise, five studies on smoking, and four studies on sleep were identified. Findings show positive relations between interoceptive domains and cognitive leisure and relaxation activities, eating behavior, and exercise. Conversely, the consumption of alcohol is negatively related to interoceptive domains. Studies in the smoking and sleep lifestyle factors were sparse and of varying methodological quality.

DISCUSSION

The findings of this review show that interoceptive domains are associated with various lifestyle factors, but the quality of the evidence is limited. Future longitudinal studies with more objective measures of interoception are needed in order to better understand the interrelations between interoception and lifestyle factors.

The effects of alcohol use severity and polygenic risk on gray matter volumes in young adults

Genetic factors contribute to alcohol misuse. Chronic alcohol consumption is associated with decreases in gray matter volumes (GMVs) of the brain. However, it remains unclear whether or how genetic risks may alter GMVs independent of the effects of alcohol exposure. Here, we employed the Human Connectome Project data of neurotypical adults (n = 995; age 22-35; 618 women) and, with voxel-based morphometry analysis, computed the GMVs of 166 regions in the automated anatomical atlas 3. Alcohol use behaviors were assessed with the Semi-Structured Assessment for the Genetics of Alcoholism. Alcohol use severity was quantified by the first principal component (PC1) identified of principal component analysis of 15 drinking measures. Polygenic risk scores (PRS) for alcohol dependence were computed for all subjects using the Psychiatric Genomics Consortium study of alcohol dependence as the base sample. With age, sex, race, and total intracranial volume as covariates, we evaluated the relationships of regional GMVs with PC1 and PRS together in a linear regression. PC1 was negatively correlated with GMVs of right insula and Heschl's gyrus, and PRS was positively correlated with GMVs of left posterior orbitofrontal cortex, bilateral intralaminar nuclei of the thalamus and lingual gyri. These findings suggest distinct volumetric neural markers of drinking severity and genetic risks of alcohol misuse. Notably, in contrast to volumetric reduction, the genetic risks of dependent drinking may involve larger regional volumes in the reward, emotion, and saliency circuits.

The effect of hypoxia on interoception in patient with obstructive sleep apnea

PURPOSE

Obstructive Sleep Apnea (OSA) is the most common sleep-related disorder. Interoception is the collection of sensory and cognitive processes that involve receiving and interpreting physiological signals from internal body structures and conveying the perception of inner sensations. In this study, it was hypothesized that the impairment in cognitive functions associated with chronic hypoxemia and the insular effects due to OSA would negatively affect interoceptive functions. The aim of this study was to evaluate whether interoception in OSA changes consistent with the hypothesis.

METHODS

A total of 102 patients diagnosed with OSA were included in this study. All participants were divided into groups based on their T90 values: desaturated OSA (T90 ≥ 20%) and non-desaturated OSA (T90 < 20%). The Heartbeat Counting Task was used to assess interoceptive accuracy, while the Interoceptive Sense Questionnaire (ISQ) was employed to identify subjective challenges in evaluating interoception.

RESULTS

Interoceptive accuracy was lower in the desaturated OSA group than in the non-desaturated OSA group (Z = -2.463; p = 0.014). Interoceptive accuracy was negatively correlated with the body mass index (r = -0.228; p = 0.021), T90 (r = -0.269; p = 0.006), and positively correlated with the average SaO2 (r = 0.377; p < 0.001) and SaO2 nadir (r = 0.243; p = 0.014).

CONCLUSION

This study examined interoceptive functions in patients with OSA. It was concluded that interoceptive accuracy is affected by the severity of hypoxia as hypothesized.

Interoceptive Processing in Substance Use Disorders (SUDs): From the Neuroanatomy to Insights from Computational Models and Predictive Coding Frameworks

Substance use disorders (SUDs) represent complex public health challenges characterized by a blend of genetic, cognitive, environmental, and psychosocial factors. This chapter explores the critical role of interoceptive processing - the internal sensing of physiological states - in the neurobiology and treatment of SUDs. Interoceptive dysfunctions are highlighted as central to the craving, emotional regulation, and decision-making processes that underpin addictive behaviors. The importance of the insula in sustaining drug use, particularly nicotine, underscores a broader involvement of interoceptive pathways in SUDs. Altered interoceptive processing is evident across various SUDs, where individuals demonstrate both a heightened sensitivity to drug-related cues and a diminished ability to process aversive stimuli, suggesting substantial neurobiological underpinnings that complicate treatment outcomes. Moreover, we delve into the theoretical and computational approach to understanding interoceptive processing in SUDs. This perspective utilizes a predictive coding framework, positing that the brain continuously generates and updates predictions about internal states based on sensory inputs. In SUDs, disruptions in this predictive mechanism can lead to inaccuracies in interoceptive perception, contributing significantly to the compulsive nature of drug-seeking behaviors and the challenges associated with treatment. We explore how computational models, such as Bayesian inference, provide insights into the interplay between expected and received interoceptive signals, highlighting the role of hyper-precise prior beliefs in the persistence of craving and impulsivity. This theoretical approach not only deepens our understanding of the neural and cognitive bases of addiction but also suggests novel intervention strategies. By recalibrating interoceptive predictions through targeted therapies, such as neuromodulation and mindfulness training, we can potentially restore the interoceptive accuracy, thereby offering new avenues for effective treatment of SUDs.

Let's focus on the insula in addiction: A refined anatomical exploration of insula in severe alcohol and cocaine use disorders

BACKGROUND

Theoretical and empirical contributions have identified insula as key in addiction. However, anatomical modifications of the insula in addictive states, and their variations across substance use disorders (SUDs), remain to be specifically explored. We therefore explored the specificities and commonalities of insula gray matter (GM) alterations in severe alcohol use disorder (sAUD) and severe cocaine use disorder (sCUD).

METHODS

We explored insula GM volume through a refined parcellation in 12 subregions (six bilateral): anterior inferior cortex (AIC), anterior short gyrus, middle short gyrus, posterior short gyrus, anterior long gyrus (ALG), and posterior long gyrus (PLG). Using a linear mixed model analysis, we explored the insula volume profiles of 50 patients with sAUD, 61 patients with sCUD, and 36 healthy controls (HCs).

RESULTS

In both sAUD and sCUD, we showed overall insular lower volume with a right-sided lateralization effect, and a major volume deficit in bilateral ALG. Moreover, differences emerged across groups, with higher left AIC and PLG volume deficits in sCUD compared to sAUD and HC.

CONCLUSIONS

We offered the first joint exploration of GM insular volumes in two SUD through refined parcellation, thus unveiling the similarities and dissimilarities in volume deficit profiles. Our results bring evidence complementing prior ones suggesting the core role of the right and posterior insula in craving and interoception, two crucial processes in addiction. Left AIC and PLG group differences also show that, while insula is a region of interest in SUD, sCUD and sAUD generate distinct insular profiles, which might parallel clinical differences across SUD.

Drug discrimination learning: Interoceptive stimulus control of behavior and its implications for regulated and dysregulated drug intake

Drug discrimination research has generated rich evidence for the capacity of interoceptive drug stimuli to control behavior by serving as discriminative cues. Owing to its neuropharmacological specificity, drug discrimination learning has been widely used to characterize the stimulus effects and neuropharmacological underpinning of drugs. Apart from such utility, discriminative drug stimuli may help regulate drug use by disambiguating conditioned associations and post-intake outcomes. First, this review summarizes the evidence supporting interoceptive regulation of drug intake from the literature of exteroceptive discriminative control of drug-related behavior, effects of drug priming, and self-titration of drug intake. Second, an overview of interoceptive control of reward-seeking and the animal model of discriminated goal-tracking is provided to illustrate interoceptive stimulus control of the initiation and patterning of drug intake. Third, we highlight the importance of interoceptive control of aversion-avoidance in the termination of drug-use episodes and describe the animal model of discriminated taste avoidance that supports such a position. In bridging these discriminative functions of drug stimuli, we propose that interoceptive drug stimuli help regulate intake by disambiguating whether intake will be rewarding, nonrewarding, or aversive. The reflection and discussion on current theoretical formulations of interoceptive control of drug intake may further scientific advances to improve animal models to study the mechanisms by which interoceptive stimuli regulate drug intake, as well as how alterations of interoceptive processes may contribute to the transition to dysregulated drug use.

Changes in interoception before and after treatment in patients with alcohol use disorder

AIMS

To investigate the factors associated with interoception in patients with alcohol use disorder and determine whether treatment causes changes in their interoception.

METHODS

The Body Perception Questionnaire-Body Awareness ultra-short version Japanese version (BPQ-BAVSF-J) was used to measure interoception in 50 alcohol-dependent participants (27 in the inpatient group and 23 in the outpatient group). The BPQ-BAVSF-J was administered and data on aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma-glutamyl transpeptidase (γ-GTP), mean corpuscular volume, platelet count, and Fib-4 index were extracted at admission and immediately before discharge for the inpatient group and at the first outpatient visit and approximately 3 months after the visit for the outpatient group.

RESULTS

The mean age of the 50 participants was 51.0 ± 12.3 years. Significant associations were found between the BPQ-BAVSF-J and Fib-4 index and AST. The BPQ-BAVSF-J score significantly decreased at discharge in the inpatient group. AST, ALT, γ-GTP, and Fib-4 index of liver function were also significantly lower at discharge. In contrast, in the outpatient group, there were no significant changes in the BPQ-BAVSF-J score, AST level, ALT level, γ-GTP level, and Fib-4 index between at the first outpatient visit and approximately 3 months after the visit.

CONCLUSIONS

Interoception in patients with alcohol use disorder increased with worsening liver function and decreased with improvement in liver function owing to treatment. This suggests that the BPQ-BAVSF-J score, an easily accessible scale, may be used to detect early deterioration of liver function through regular administration.

Interoceptive sensibility and alcohol craving in Polish prisoners: the role of alexithymia and emotional dysregulation

Introduction

Alcohol craving, characterized by a strong desire or compulsion to consume alcohol, is a prominent symptom of substance dependence syndrome. Research indicates that alcohol craving is a significant factor leading to the termination of abstinence. The mechanisms underlying the activation of alcohol craving remain not fully understood. The urge to reach for alcohol may be stimulated by emotions, memories, thoughts, or bodily sensations, as well as external factors. It has been postulated that individuals with high levels of interoceptive sensibility tend to exhibit a high degree of alexithymia and emotion dysregulation in the context of alcohol craving. Deficits in identifying and verbalizing emotions, along with an operational thinking style, facilitate alcohol consumption by impeding accurate insight into one's mental state, thereby hindering the comprehension of bodily states, emotions, and the regulation of self.

Method

This study involved 160 inmates incarcerated in a prison in Poland, awaiting participation in therapy for individuals with substance dependence following psychiatric diagnosis. Four questionnaires were used in the study: multidimensional Assessment of Interoceptive Sensibility (MAIA) for interoceptive sensibility, Toronto Alexithymia Scale (TAS-20) for alexithymia, Difficulties in Emotion Regulation Scale (DERS) for emotional dysregulation, and the Penn Alcohol Craving Scale (PACS) for alcohol craving assessment.

Results

The results of the study are as follows: the study findings indicated that alexithymia and emotional dysregulation significantly mediates the relationship between interoceptive sensibility and alcohol craving. The indirect effect for both factors was found to be significant, similar to the indirect effect observed for alexithymia as an mediator. However, in the case of emotional dysregulation, no significant indirect effect was observed.

Conclusion

Our study provides insights into the potential contribution of interoceptive sensibility to the heightened risk of alcohol dependence. Specifically, impaired interoceptive sensibility may be associated with the development of alexithymia and emotional dysregulation, potentially rendering individuals more susceptible to alcohol craving. Interoceptive sensibility could serve as a prerequisite for the cultivation of positive emotional processing skills.

Where alcohol use disorder meets interoception: A meta-analytic view on structural and functional neuroimaging data

Alcohol use disorder (AUD) has been associated with changes in the processing of internal body signals, known as interoception. Changes in brain structure, particularly in the insula, are thought to underlie impaired interoception. As studies specifically investigating this association are largely lacking, this analysis takes an approach that compares meta-analytic results on interoception with recently published meta-analytic results on gray matter reduction in AUD. A systematic literature search identified 25 eligible interoception studies. Activation likelihood estimation (ALE) was used to test for spatial convergence of study results. Overlap between interoception and AUD clusters was tested using conjunction analysis. Meta-analytic connectivity modeling (MACM) and resting-state functional connectivity were used to identify the functional network of interoception and to test where this network overlapped with AUD meta-analytic clusters. The results were characterized using behavioral domain analysis. The interoception ALE identified a cluster in the left middle insula. There was no overlap with clusters of reduced gray matter in AUD. MACM analysis of the interoception cluster revealed a large network located in the insulae, thalami, basal nuclei, cingulate and medial frontal cortices, and pre- and postcentral gyri. Resting state analysis confirmed this result, showing the strongest connections to nodes of the salience- and somatomotor network. Five of the eight clusters that showed a structural reduction in AUD were located within these networks. The behavioral profiles of these clusters were suggestive of higher-level processes such as salience control, somatomotor functions, and skin sensations. The results suggest an altered salience mapping of interoceptive signals in AUD, consistent with current models. Connections to the somatomotor network may be related to action control and integration of skin sensations. Mindfulness-based interventions, pleasurable touch, and (deep) transcranial magnetic stimulation may be targeted interventions that reduce interoceptive deficits in AUD and thus contribute to drug use reduction and relapse prevention.

Human laboratory models of reward in substance use disorder

Human laboratory models in substance use disorder provide a key intermediary step between highly controlled and mechanistically informative non-human preclinical methods and clinical trials conducted in human populations. Much like preclinical models, the variety of human laboratory methods provide insights into specific features of substance use disorder rather than modelling the diverse causes and consequences simultaneously in a single model. This narrative review provides a discussion of popular models of reward used in human laboratory research on substance use disorder with a focus on the specific contributions that each model has towards informing clinical outcomes (forward translation) and analogs within preclinical models (backward translation). Four core areas of human laboratory research are discussed: drug self-administration, subjective effects, behavioral economics, and cognitive and executive function. Discussion of common measures and models used, the features of substance use disorder that these methods are purported to evaluate, unique issues for measure validity and application, and translational links to preclinical models and special considerations for studies wishing to evaluate homology across species is provided.

Assessment on interoceptive awareness on alcohol use and gambling disorders reveals dissociable interoceptive abilities linked to external and internal dependencies: Practical use of Body Perception Questionnaire Very Short Form (BPQ-VSF) in clinical settings

Interoception is one of the pivotal cognitive functions for mechanisms of our body awareness, and malfunction of the interoceptive network is thought to be associated with mental illness, including addiction. Within addictive disorders, substance-based and non-substance-based addictions are known to hold dissociable reward systems. However, little is known about how interoceptive awareness between these addiction sub-types would differ. Subjective interoceptive awareness was assessed among patients with alcohol use disorder (n = 50) who were subsequently hospitalized or remained out-patient and gambling addiction (n = 41) by the Body Awareness component of the Japanese version of the Body Perception Questionnaire (BPQ-VSFBA-J) and compared them against healthy control (n = 809). Both addiction groups showed significantly lower BPQ than the control, with no substantial differences between inpatients and outpatients for alcohol samples. Notably, BPQ scores for gambling patients were significantly lower than those for the alcohol group. This evidence may suggest a putative role of interoceptive ability on the severity of behavioral addiction over substance-based addiction.

Connected minds in disconnected bodies: Exploring the role of interoceptive sensibility and alexithymia in problematic use of the internet

INTRODUCTION

The ever-increasing prominence of the internet and digital technology in our society requires a deeper examination of how these developments alter perception of our bodies and emotions. One such consequence is the emergence of Problematic Use of the Internet (PUI) - an array of compulsive or addictive behaviors mediated by the web that detrimentally affect an individual's functioning. This suggests that some people may be shifting their consciousness from the physical realm to the digital world. The objective of this study was to investigate how shortcomings in interoception (the sensibility to bodily signals) and alexithymia (an inability to identify and express emotions) might contribute to PUI.

METHODS

The Internet Addiction Test (IAT), the Toronto Alexithymia Scale (TAS-20), and the Multidimensional Assessment of Interoceptive Awareness (MAIA) were used to assess a sample of 1076 adolescents and young adults aged between 16 and 26 years via an online survey. Data analysis was based on t-test, correlations and multivariate regression.

RESULTS

26.8% (n = 288) of participants met the criteria for moderate PUI. Individuals with PUI displayed higher levels of alexithymia (p < 0.001) and diminished abilities in certain aspects of interoceptive sensibility, including placing trust in their own bodily signals (p = 0.006), not responding excessively to uncomfortable sensations with worry (p < 0.001), and not denying them (p = 0.006). Multivariate modelling revealed associations between PUI and the following factors: having a boyfriend/girlfriend (aOR = 5.70), substance use (aOR = 1.78), difficulty in identifying feelings (aOR = 1.09), externally oriented thinking (aOR = 1.05), low disposition in perceiving body sensations (aOR = 0.25), tendency to become distracted (aOR = 0.82) or excessively worried (aOR = 0.11) in the face of pain. Furthermore, the analysis indicated how these aspects of body perception may be interrelated, either enhancing or reducing the risk of PUI when examined individually, collectively, or in combination.

CONCLUSIONS

This study underlines the potential connection between difficulties in the mind-body interaction and the development of PUI. It suggests a bidirectional relationship between excessive digital device use and distorted bodily interoceptive processes in PUI, reinforcing the notion that individuals struggling with emotion identification and expression may be more prone to excessive internet usage. To further comprehend the relevance of these constructs in PUI, it is necessary to conduct more targeted investigations and longitudinal studies.

Bodily confusion: Lower differentiation of emotional and physiological states in student alcohol users

BACKGROUND

Alexithymia, difficulty in recognising and naming emotions, is common among people who use alcohol. There is also emerging evidence that people with alexithymia are unable to distinguish emotions from non-emotional physiological states. The project aimed to test if alcohol use is related to the way student drinkers experience emotions and physiological states in the body.

METHODS

We employed a novel method to study bodily sensations related to emotions and physiological states in the context of alcohol use: the emBODY tool, which allowed participants to mark areas of the body in which they experience various emotions and physiological states.

RESULTS

Students who showed a hazardous pattern of alcohol use (alcohol use disorders identification test [AUDIT] score ≥ 7, N = 91), overall, presented higher alexithymia levels and coloured larger areas for emotions and physiological states (showed less specificity) than those who show low-risk alcohol consumption (AUDIT ≤ 4, N = 90). Moreover, statistical classifiers distinguished feeling-specific maps less accurately for hazardous drinkers than low-risk drinkers [F(1,1998) = 441.16; p < 0.001], confirming that higher alcohol use is related to higher confusion of emotional and non-emotional bodily feelings.

CONCLUSIONS

Plausibly, this increased bodily confusion drives alcohol consumption: alcohol may serve as a means of dealing with undifferentiated changes in psychophysiological arousal accompanying emotional states.

Insular volumetry in severe alcohol use disorder and Korsakoff's syndrome through an anatomical parcellation: Let us go back to basics

Functional neuroimaging has demonstrated the key role played by the insula in severe alcohol use disorder (sAUD), notably through its involvement in craving and body signals processing. However, the anatomical counterpart of these functional modifications in sAUD patients with and without neurological complications remains largely unexplored, especially using state-of-the-art parcellation tools. We thus compared the grey matter volume of insular subregions (form anterior to posterior: anterior inferior cortex, anterior short gyrus, middle short gyrus, posterior short gyrus, anterior long gyrus, posterior long gyrus) in 50 recently detoxified patients with sAUD, 19 patients with Korsakoff's syndrome (KS) and 36 healthy controls (HC). We used a mixed linear model analysis to explore group differences in the six subregions grey matter volume and lateralization differences. Insular macrostructure was globally affected to the same extent in sAUD with and without KS, indicating that these brain abnormalities may be related to alcohol consumption per se, rather than to the presence of alcohol-related neurological complications. Insular atrophy showed a right-sided lateralization effect and was especially marked in the posterior insula, a region associated with visceral information processing and the embodiment effect of a substance, from which craving arises. Anatomical damages might thus underlie the previously reported altered insular activations and their behavioural counterparts.

Interoception, alexithymia, and anxiety among individuals with alcohol use disorder

Background

Interoception (i.e., the ability to recognize bodily signals), alexithymia (i.e., the inability to recognize emotional states) and negative affect (i.e., unpleasant feelings such as anxiety) have been associated with alcohol use disorder (AUD). Previous research suggests that interoception may underlie alexithymia, which in turn may be associated with negative affectivity. However, this remains to be empirically tested. This study investigates whether alexithymia mediates the association between interoception and anxiety and whether this association differs across individuals with AUD and a healthy control (HC) comparison group.

Methods

The AUD group consisted of 99 participants enrolled in an 8-week abstinence-based inpatient treatment program. The HC group included 103 healthy individuals. The heartbeat counting task (HCT) was used to assess interoception (cardiac interoceptive accuracy). The Toronto Alexithymia Scale (TAS-20) was used to assess alexithymia. The Brief Symptom Inventory (BSI) was used to assess anxiety.

Results

The moderated mediation model with interoception as the predictor, alexithymia as the mediator, and negative affect (i.e., state anxiety) as the dependent variable was tested. The analysis showed that the conditional indirect effect of interoception on anxiety via alexithymia was significant for individuals with AUD [ab = -0.300, bootstrap 95% CI = (-0.618, -0.088)], as well as for HCs [ab = -0.088, bootstrap 95% CI = (-0.195, -0.014)]; however, the conditional indirect effect significantly differed across HCs and individuals with AUD. Namely, the mediated effect was greater among individuals with AUD compared to the HC group.

Conclusion

The results suggests that interoceptive impairment contributes to greater negative affect (i.e., state anxiety) via alexithymia especially for individuals with AUD. Improving emotion recognition via therapeutic methods focused on strengthening interoceptive abilities could improve outcomes for individuals receiving treatment for AUD.

Ready, set, …and difficultly slowing down: What role does alexithymia, emotional regulation and interoceptive awareness play in exercise dependence?

Alexithymia is associated with a diverse range of addictive behaviours including exercise addiction symptoms. In addition, emerging research indicates that emotional regulation and interoceptive processes may help explain this relationship. Thus, the current study tested the ability of emotion regulation to mediate the relationship between alexithymia and exercise addiction symptoms and whether interoceptive awareness moderates these relationships. A total of 404 physically active adults (86.8 % female) completed measures of alexithymia, exercise dependence symptoms, difficulties with emotion regulation and interoceptive awareness (Mage = 43.72, SD = 14.09). Alexithymia, emotion regulation, interoceptive awareness and exercise dependence symptoms were all significantly correlated. Further analysis revealed that emotional regulation mediated the relationship between alexithymia and exercise dependence, although the mediation model did not vary as a function of interoceptive awareness. These findings underscore the importance of considering emotion-focused processes in treatment planning and other initiatives designed to help individuals who display exercise dependence symptoms.

Interoception Within the Context of Impulsivity and Addiction

Purpose of Review

The goal of this review is to examine the relationship between impulsivity and interoception in addiction, to summarize the current understanding of the topic, identify any gaps in knowledge, and provide directions for future research.

Research Findings

Interoception may be a contributing factor to impulsive behaviour and, thus, addiction. Substance abuse can negatively impact the brain's ability to process interoceptive information and impact the reward system, leading to decreased sensitivity to natural rewards and increased sensitivity to drugs. There is potential for new therapies, such as mindfulness, interoceptive training, brain stimulation, or vagal nerve stimulation to target both impulsivity and interoception in the treatment of addiction.

Summary

Despite a growing interest in interoception in addiction research, further research is needed to better understand the role of interoception in addiction and to develop new methods for studying how individuals with addiction process and perceive internal bodily sensations.

Alexithymia and Alcohol Use: Evaluating the Role of Interoceptive Sensibility with the Revised Multidimensional Assessment of Interoceptive Awareness

Alexithymia has been linked to risky or problematic alcohol use, with a common interpretation invoking deficient emotion regulation and use of alcohol to cope with distress. An alternative explanation positing a general deficit of interoception in alexithymia suggested that poor awareness of internal cues of overconsumption may promote excessive drinking. The present study assessed predictions based on these hypotheses in 337 young adult alcohol users recruited online. Participants completed validated questionnaire indices of alcohol use, alexithymia, emotion regulation, interoceptive sensibility, and sensitivity to reward and punishment. Alcohol use was positively correlated with alexithymia and reward sensitivity, and negatively correlated with emotion regulation as expected, but was uncorrelated with interoceptive sensibility. Alexithymia was not significantly correlated with most dimensions of interoceptive sensibility but was highly negatively correlated with emotion regulation. Hierarchical regression controlling for demographic variables indicated that alexithymia, emotion regulation, sex, and sensitivity to reward and punishment were significant predictors of alcohol use levels. Bootstrapped mediation test controlling for all other variables indicated mediation of the association between alexithymia and alcohol use by deficient emotion regulation but not interoceptive sensibility. Results supported the emotion regulation deficit interpretation of the association of alexithymia with alcohol use. Limitations concerning interoception measurement, online samples, self-report measures, cross-sectional designs, and collection of data during the COVID-19 pandemic are discussed. Future research could follow up on these findings by testing interoceptive accuracy in addition to interoceptive sensibility in relation to alexithymia and alcohol use.

Relationship of Interoceptive Accuracy With Risky Decision-Making and Treatment Outcomes in Male Patients With Alcohol Use Disorder

Abstract. Lower levels of interoceptive awareness (IA) may be present in individuals with substance use disorder (SUD), and damage to related brain regions caused by substance use may disrupt IA. Disturbance in the bodily feedback system may fail to engage in effective decision-making. This study focused on the premise that interoceptive accuracy (IAc), as the primary construct of IA, is implicated in SUD and that poor IAc is linked to risky decision-making and adversely affects treatment outcomes. Eighty-five patients with alcohol use disorder (AUD) (current severity: moderate or severe) and 87 healthy control subjects were enrolled in the present study. All participants performed the heart rate tracking task and a computerized version of the Iowa gambling task (IGT). Characteristics of patients’ addiction profiles were assessed with the Addiction Profile Index (API) Clinical Form. IAc and IGT scores of patients with AUD were lower than healthy controls. IGT scores of patients with low IAc were lower than those of patients with high IAc and decreased IAc is predictive of decreased IGT scores. No significant differences were determined in treatment outcomes at 3, 6, and 12 months after hospitalization between the low-IAc and high-IAc patient groups. Our results suggest that IAc is implicated in AUD and that poor IAc is predictive of increased risky decision-making. Risky decision-making that results in substance use may be partly related to a deficit in the interoceptive ability to guide behavior. Focus on IAc without reference to complex clinical case presentations in AUD makes it difficult to draw any definitive conclusions about the role of IAc in clinical outcomes.