Disrupted regulation of social exclusion in alcohol-dependence: an fMRI study

Blunted reward-related activation to food scenes distinguishes individuals with alcohol use disorder in a pilot case-control fMRI pilot study

BACKGROUND

Alcohol use disorder (AUD) is thought to bias the neurocircuitry underlying reward processing and motivation to preferentially attend to conditioned alcohol cues over natural rewards. The present case-control pilot study evaluated this hypothesis using novel natural reward paradigms.

METHODS

Twenty-eight participants (AUD, n = 14, light drinkers, n = 14) were recruited-AUD participants reported 44.0% heavy drinking days (%HDD) and 4.67 drinks/day over the preceding 90 days. Functional magnetic resonance imaging (fMRI) data were acquired during the administration of three separate picture-viewing paradigms of alcohol cues, food scenes, and social reward, respectively. Independent samples t-tests were performed to compare groups' fMRI data and exploratory correlation analyses were performed to examine associations with clinical characteristics of AUD.

RESULTS

Food scenes elicited abnormally low reward-related activation, within the superior frontal gyrus and caudate bilaterally, among AUD participants. Lower activation to food scenes within the superior frontal gyrus was, in turn, associated with higher levels of past-month %HDD among AUD participants, specifically, along with craving and alcohol dependence severity when examined across the full sample. Contrasting reward types (e.g., alcohol cues vs. food scenes) did not reveal "preferential" activation to differentiate groups.

CONCLUSIONS

Heavy drinking appears associated with reduced responsivity to natural rewards, specifically food rather than social cues. Neural mechanisms underlying the high prevalence of malnutrition among individuals with AUD may involve some combination of blunted approach-related affect and reduced craving-related motivation to eat when food is present, resulting in limited engagement of cortico-striato-thalamic motor circuitry supporting food acquisition. However, given the preliminary nature of this pilot study, such formulations remain tentative until larger follow-up studies can be conducted. From a potential translational standpoint, the ability of promising therapeutics to demonstrate increased responsivity to natural rewards, specifically nutritive reward may serve as a valuable complementary efficacy indicator for future clinical neuroimaging trials in AUD.

Is severe alcohol use disorder really associated with increased utilitarian moral judgment? Exploration using the CNI model

OBJECTIVES

The psychology of moral decision-making classically contrasts utilitarianism (based on consequences) and deontology (based on moral norms). Previous studies capitalizing on this dichotomy have suggested the presence of a utilitarian bias among patients with severe alcohol use disorder (SAUD). We aimed to further disentangle the processes involved in such bias through a more validated approach, the CNI model of moral decision-making. This model allows to go further than the classical approach by distinguishing sensitivity to consequences (C), to moral norms (N), and general preference for inaction over action (I) in response to moral dilemmas.

METHODS

Thirty-four recently detoxified patients with SAUD and 34 matched control participants completed a battery of 48 dilemmas derived from the CNI model, as well as social cognition tasks.

RESULTS

In contrast with the utilitarian bias suggested in previous studies based on the classical approach, patients with SAUD did not show an increased sensitivity to consequences in comparison with control participants. However, they showed a reduced sensitivity to moral norms, as well as a greater action tendency. These biases were not related to social cognition deficits.

CONCLUSIONS

Patients with SAUD are not more utilitarian than healthy controls, this previously reported bias being artificially generated by the methodological limits of the classical approach. Instead, they present a reduced sensitivity to moral norms and an action bias, which might impact their interpersonal relations and contribute to the social isolation frequently reported in this population, thus identifying moral decision-making as a new therapeutic lever in SAUD.

Neural correlates of proactive avoidance deficits and alcohol use motives in problem drinking

Physical pain and negative emotions represent two distinct drinking motives that contribute to harmful alcohol use. Proactive avoidance, in contrast, can reduce consumption in response to these motives but appears to be impaired in those with problem drinking. Despite such evidence, proactive avoidance and its underlying neural deficits have not been assessed experimentally. How these deficits inter-relate with drinking motives to influence alcohol use also remains unclear. The current study leveraged neuroimaging data in forty-one problem and forty-one social drinkers who performed a probabilistic learning go/nogo task featuring proactive avoidance of painful outcomes. We identified the brain responses to proactive avoidance and contrasted the neural correlates of drinking to avoid negative emotions vs. physical pain. Behavioral results confirmed proactive avoidance deficits in problem drinking individuals' learning rate and performance accuracy, both which were associated with greater alcohol use. Imaging findings in the problem drinking group showed that negative emotions as a drinking motive predicted attenuated right anterior insula activation during proactive avoidance. In contrast, physical pain motive predicted reduced right putamen response. These regions' activations as well as functional connectivity with the somatomotor cortex also demonstrated a negative relationship with drinking severity and positive relationship with proactive avoidance performance. Path modeling further delineated the pathways through which physical pain and negative emotions influenced the neural and behavioral measures of proactive avoidance. Taken together, the current findings provide experimental evidence for proactive avoidance deficits in alcohol misuse and establish the link between their neural underpinnings and drinking behavior.

Involvement of the gut microbiome-brain axis in alcohol use disorder

The human intestine is colonized by a variety of microorganisms that influence the immune system, the metabolic response, and the nervous system, with consequences for brain function and behavior. Unbalance in this microbial ecosystem has been shown to be associated with psychiatric disorders, and altered gut microbiome composition related to bacteria, viruses, and fungi has been well established in patients with alcohol use disorder. This review describes the gut microbiome-brain communication pathways, including the ones related to the vagus nerve, the inflammatory cytokines, and the gut-derived metabolites. Finally, the potential benefits of microbiota-based therapies for the management of alcohol use disorder, such as probiotics, prebiotics, and fecal microbiota transplantation, are also discussed.

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.

Deficits in proactive avoidance and neural responses to drinking motives in problem drinkers

Physical pain and negative emotions represent two distinct drinking motives that contribute to harmful alcohol use. Proactive avoidance which can reduce problem drinking in response to these motives appears to be impaired in problem drinkers. However, proactive avoidance and its underlying neural deficits have not been assessed experimentally. How these deficits inter-relate with drinking motives to influence alcohol use also remains unclear. The current study leveraged neuroimaging data collected in forty-one problem and forty-one social drinkers who performed a probabilistic learning go/nogo task that involved proactive avoidance of painful outcomes. We characterized the regional brain responses to proactive avoidance and identified the neural correlates of drinking to avoid physical pain and negative emotions. Behavioral results confirmed problem drinkers' proactive avoidance deficits in learning rate and performance accuracy, both which were associated with greater alcohol use. Imaging findings in problem drinkers showed that negative emotions as a drinking motive predicted attenuated right insula activation during proactive avoidance. In contrast, physical pain motive predicted reduced right putamen response. These regions' activations as well as functional connectivity with the somatomotor cortex also demonstrated a negative relationship with drinking severity and positive relationship with proactive avoidance performance. Path modeling further delineated the pathways through which physical pain and negative emotions, along with alcohol use severity, influenced the neural and behavioral measures of proactive avoidance. Taken together, the current findings provide experimental evidence for proactive avoidance deficits in problem drinkers and establish the link between their neural underpinnings and alcohol misuse.

Links between psychopathological symptoms and cortical thickness in men with severe alcohol use disorder: A Magnetic Resonance Imaging study

BACKGROUND

Anxiety and depression are psychopathological states frequently co-occurring with severe alcohol use disorder (SAUD). These symptoms generally disappear with abstinence but may persist in some patients, increasing the relapse risk.

METHODS

The cerebral cortex thickness of 94 male patients with SAUD was correlated with symptoms of depression and anxiety, both measured at the end (2-3 weeks) of the detoxification treatment. Cortical measures were obtained using surface-based morphometry implemented with Freesurfer.

RESULTS

Depressive symptoms were associated with reduced cortical thickness in the superior temporal gyrus of the right hemisphere. Anxiety level was correlated with lower cortical thickness in the rostral middle frontal region, inferior temporal region, and supramarginal, postcentral, superior temporal, and transverse temporal regions of the left hemisphere, as well as with a large cluster in the middle temporal region of the right hemisphere.

CONCLUSIONS

At the end of the detoxification stage, the intensity of depressive and anxiety symptoms is inversely associated with the cortical thickness of regions involved in emotions-related processes, and the persistence of the symptoms could be explained by these brain deficits.

Distinct dynamic behavioural response to social exclusion in male patients with a history of alcohol dependence

Social exclusion contributes to alcohol consumption, whereas the development of alcohol dependence (AD) can in turn lead to the social exclusion of people with AD. Previous research observed altered neural responses to experimentally induced social exclusion (i.e., Cyberball game) in patients with AD. In addition, inflammation has been associated with both social behaviours and AD. Our study aimed to investigate the dynamic behavioural response and the inflammatory effects of social exclusion in male patients with a history of AD. To this end, we analysed dynamic changes in ball tossing during a partial exclusion Cyberball game and the cytokine interleukin (IL)-1b in saliva in 31 male patients who had a history of AD and 29 gender-matched healthy controls without AD. Participants were included in the first 2 min of the Cyberball game and then excluded by one of the two co-players in the proceeding 5 min. Saliva was collected three times: one before and two after the Cyberball game. Across groups, participants passed the ball more often to the excluder during the partial exclusion period. Analysis using piece-wise linear mixed models showed that patients rapidly increased ball tosses to the excluder upon exclusion, which lasted to the late response phase, whereas the early behavioural response to exclusion took longer for controls. There was no significant change of salivary IL-1b level to exclusion in either patients or controls. The results indicate a distinct dynamic behavioural response to social exclusion in male patients with a history of AD.

Rejection sensitivity in severe alcohol use disorder: Increased anxious anticipation of rejection

Rejection sensitivity (RS) reflects the disposition to anxiously expect, readily perceive, and disproportionately react to rejection. It is linked to interpersonal problems and psychopathological symptoms, which are frequent in severe alcohol use disorder (SAUD) and are known to influence clinical outcomes. Consequently, RS has been put forward as a process of interest in this disorder. However, empirical studies investigating RS in SAUD are scarce and focused on its last two components, leaving the core process of anxious expectations of rejection unexplored. To fil this gap, 105 patients with SAUD and 73 age-and-gender-matched controls completed the validated Adult Rejection Sensitivity Scale. We computed anxious anticipation (AA), and rejection expectancy (RE) scores, corresponding to the affective and cognitive dimensions of anxious expectations of rejection, respectively. Participants also completed measures of interpersonal problems and psychopathological symptoms. We found that patients with SAUD had higher AA (affective dimension) but not RE (cognitive dimension) scores. Moreover, AA was associated with interpersonal problems as well as psychopathological symptoms in the SAUD sample. These findings meaningfully extend the RS and social cognition literatures in SAUD by showing that difficulties already arise at the anticipatory stage of socio-affective information processing. Moreover, they shed light on the affective component of anxious expectations of rejection as a novel, clinically relevant process in this disorder.

Decreased inter-brain synchronization in the right middle frontal cortex in alcohol use disorder during social interaction: An fNIRS hyperscanning study

BACKGROUND

Alcohol use disorder (AUD) is a widespread mental disorder and has thrust a heavy burden on the health system all over the world. Social cognition and function are reported to be impaired in AUD, but its neural mechanism is rarely investigated. The current study attempts to fill this gap.

METHODS

28 subjects with AUD and 36 healthy controls (HC) were recruited in this study and were paired into 14 AUD dyads and 18 HC dyads. The drinking problems, depression, anxiety, and impulsivity of subjects were measured. Each dyad completed cooperation and competition tasks with simultaneous frontal functional near-infrared spectroscopy (fNIRS) hyperscanning recording. The inter-brain synchronization (IBS) in the frontal cortex was calculated for each dyad and compared between AUD and HC. The significantly altered IBS in AUD was correlated with clinical measures to explore possible influencing factors.

RESULTS

The IBS in the right middle frontal cortex was significantly decreased in AUD under both cooperation (t = -2.257, P = 0.028) and competition (t = -2.488, P = 0.016) task. The IBS during the cooperation task in the right middle frontal cortex in AUD was negatively correlated with non-planning impulsivity (r = -0.673, P = 0.006).

LIMITATIONS

This study used cross-sectional data, which limited the causal inference. The synchronization between other brain regions besides the frontal cortex should be further explored in patients with AUD.

CONCLUSION

The current study could provide new insights into the neural mechanism of social dysfunction in AUD and facilitate clinical intervention in future practice.

Fear of missing out (FOMO) associates with reduced cortical thickness in core regions of the posterior default mode network and higher levels of problematic smartphone and social media use

BACKGROUND AND AIMS

Fear of missing out (FOMO) promotes the desire or urge to stay continuously connected with a social reference group and updated on their activities, which may result in escalating and potentially addictive smartphone and social media use. The present study aimed to determine whether the neurobiological basis of FOMO encompasses core regions of the reward circuitry or social brain, and associations with levels of problematic smartphone or social media use.

METHODS

We capitalized on a dimensional neuroimaging approach to examine cortical thickness and subcortical volume associations in a sample of healthy young individuals (n = 167). Meta-analytic network and behavioral decoding analyses were employed to further characterize the identified regions.

RESULTS

Higher levels of FOMO associated with lower cortical thickness in the right precuneus. In contrast, no associations between FOMO and variations in striatal morphology were observed. Meta-analytic decoding revealed that the identified precuneus region exhibited a strong functional interaction with the default mode network (DMN) engaged in social cognitive and self-referential domains.

DISCUSSION AND CONCLUSIONS

Together the present findings suggest that individual variations in FOMO are associated with the brain structural architecture of the right precuneus, a core hub within a large-scale functional network resembling the DMN and involved in social and self-referential processes. FOMO may promote escalating social media and smartphone use via social and self-referential processes rather than reward-related processes per se.

An eye-tracking study of biased attentional processing of emotional faces in severe alcohol use disorder

BACKGROUND

Social cognition impairments in severe alcohol use disorder (SAUD) are increasingly established. However, fundamental aspects of social cognition, and notably the attentional processing of socio-affective information, remain unexplored, limiting our understanding of underlying mechanisms. Here, we determined whether patients with SAUD show attentional biases to specific socio-affective cues, namely emotional faces.

METHOD

In a modified dot-probe paradigm, 30 patients with SAUD and 30 demographically matched healthy controls (HC) were presented with pairs of neutral-emotional (angry, disgusted, happy, sad) faces while having their eye movements recorded. Indices of early/automatic (first fixations, latency to first fixations) and later/controlled (number of fixations, dwell-time) processes were computed.

RESULTS

Patients with SAUD did not differ from HC in their attention to angry/disgusted/sad vs. neutral faces. However, patients with SAUD fixated/dwelled less on happy vs. neutral faces in the first block of stimuli than HC, who presented an attentional bias to happy faces.

LIMITATIONS

Sample-size was determined to detect medium-to-large effects and subtler ones may have been missed. Further, our cross-sectional design provides no explanation as to whether the evidenced biases precede or are a consequence of SAUD.

CONCLUSIONS

These results extend the social cognition literature in SAUD to the attentional domain, by evidencing the absence of a controlled attentional bias toward positive social cues in SAUD. This may reflect reduced sensitivity to social reward and could contribute to higher order social cognition difficulties and social dysfunction.

Negative experiences, social exclusion and unwanted attention on social media: exploring the association with adolescent alcohol use

BACKGROUND

Adolescents' presence on Social Media (SoMe) facilitates peer connections making them susceptible to peer-influences and approval. Negative experiences on SoMe can affect adolescent stress and wellbeing, impelling their use of alcohol. This paper provides a novel understanding of the relationship between negative experiences on SoMe and key indicators of alcohol use in adolescents.

METHODS

Data was collected from upper secondary school students (n = 3528, ages 16-19, 45% boys) in Bergen (Norway) using a web-based questionnaire during school-hours in 2020 and 2021. Dependent variables were alcohol consumption, binge drinking and scoring ≥ 2 points on the CRAFFT instrument screening for substance use problems in adolescents. Independent variables were two scales indicating "negative acts and exclusion" and "unwanted attention from others". Covariates included age, gender, country of birth and subjective socioeconomic status. Results are presented as relative risk ratios (RRR), odds ratios (OR) and incidence rate ratios (IRR) with 95% confidence intervals.

RESULTS

Using multinomial logistic regression models, "negative acts and exclusion" and "unwanted attention" were positively associated with trying alcohol (OR: 1.50 (95% CI 1.28-1.76) and 1.86 (95% CI 1.66-2.09) respectively, both p ≤ 0.001), with frequency and amount of alcohol consumed. Findings from logistic regression models indicated that "negative acts and exclusion" and "unwanted attention" were positively associated with i. CRAFFT-caseness (OR: 2.13 and 1.86) and ii. frequent binge drinking (OR: 1.55 and 1.89).

CONCLUSION

Both exclusion and unwanted attention on SoMe were associated with indicators of problematic drinking, including frequency, quantity, and consequences related to alcohol.

The brain in social context: A systematic review of substance use and social processing from adolescence to young adulthood

Substance use escalates between adolescence and young adulthood, and most experimentation occurs among peers. To understand underlying mechanisms, research has focused on neural response during relevant psychological processes. Functional magnetic resonance imaging (fMRI) research provides a wealth of information about brain activity when processing monetary rewards; however, most studies have used tasks devoid of social stimuli. Given that adolescent neurodevelopment is sculpted by the push-and-pull of peers and emotions, identifying neural substrates is important for intervention. We systematically reviewed 28 fMRI studies examining substance use and neural responses to stimuli including social reward, emotional faces, social influence, and social stressors. We found substance use was positively associated with social-reward activity (e.g., in the ventral striatum), and negatively with social-stress activity (e.g., in the amygdala). For emotion, findings were mixed with more use linked to heightened response (e.g., in amygdala), but also with decreased response (e.g., in insula). For social influence, evidence supported both positive (e.g., cannabis and nucleus accumbens during conformity) and negative (e.g., polydrug and ventromedial PFC during peers' choices) relations between activity and use. Based on the literature, we offer recommendations for future research on the neural processing of social information to better identify risks for substance use.

Mixing Misery and Gin: The Effect of Alcohol Administration on Ostracism Response

Williams's need-threat model proposes that ostracism responses are reflexive and, because of their evolutionary significance, difficult to diminish. Alcohol is widely consumed in social contexts and for reasons of coping with social stress, and major theories of alcohol propose that intoxication disrupts cognitive appraisal of environmental threats, leading to stress relief. Surprisingly, though, no well-powered experimental research has examined the impact of alcohol intoxication on distress from social ostracism. In three studies across two independent laboratories (N = 438), participants were randomly assigned to receive either an alcoholic or nonalcoholic (i.e., no-alcohol control or placebo) beverage and were exposed to an ostracism (or social inclusion) manipulation. Results, which emerged as remarkably consistent across all studies, indicated strong and consistent effects of ostracism on mood and needs satisfaction among both intoxicated and sober participants. Findings have important implications for ostracism theory and speak to boundary conditions for alcohol's ability to relieve stress.

Neural Underpinnings of Social Stress in Substance Use Disorders

BACKGROUND

Drug addiction is a complex brain disorder that is characterized by craving, withdrawal, and relapse, which can be perpetuated by social stress. Stemming from an acute life event, chronic stress, or trauma in a social context, social stress has a major role in the initiation and trajectory of substance use. Preclinical literature shows that early life stress exposure and social isolation facilitate and enhance drug self-administration. Epidemiological evidence links childhood adversity to increased risk for drug use and demonstrates that cumulative stress experiences are predictive of substance use severity in a dose-dependent manner. Stress and drug use induce overlapping brain alterations leading to downregulation or deficits in brain reward circuitry, thereby resulting in greater sensitization to the rewarding properties of drugs. Though stress in the context of addiction has been studied at the neural level, a gap in our understanding of the neural underpinnings of social stress in humans remains.

METHODS

We conducted a systematic review of in vivo structural and functional neuroimaging studies to evaluate the neural processes associated with social stress in individuals with substance use disorder. Results were considered in relation to participants' history of social stress and with regard to the effects of social stress induced during the neuroimaging paradigm.

RESULTS

An exhaustive search yielded 21 studies that matched inclusion criteria. Social stress induces broad structural and functional neural effects in individuals with substance use disorder throughout their lifespan and across drug classes. A few patterns emerged across studies: (1) many of the brain regions altered in individuals who were exposed to chronic social stress and during acute stress induction have been implicated in addiction networks (including the prefrontal cortex, insula, hippocampus, and amygdala); (2) individuals with childhood maltreatment and substance use history had decreased gray matter or activation in regions of executive functioning (including the medial prefrontal cortex, orbitofrontal cortex, anterior cingulate cortex), the hippocampal complex, and the supplementary motor area; and (3) during stress-induction paradigms, activation in the anterior cingulate cortex, caudate, and amygdala was most commonly observed.

CONCLUSIONS/IMPLICATIONS

A distinct overlap is shown between social stress-related circuitry and addiction circuitry, particularly in brain regions implicated in drug-seeking, craving, and relapse. Given the few studies that have thoroughly investigated social stress, the evidence accumulated to date needs to be replicated and extended, particularly using research designs and methods that disentangle the effects of substance use from social stress. Future clinical studies can leverage this information to evaluate the impact of exposure to trauma or adverse life events within substance use research. Expanding knowledge in this emerging field could help clarify neural mechanisms underlying addiction risk and progression to guide causal-experimental inquiry and novel prevention and treatment strategies.

Alcohol use and interoception - A narrative review

Interoception, defined as the ability to perceive and interpret body signals, may play an important role in alcohol use disorder (AUD). Earlier studies suggested an association between interoception impairment and known risk factors for AUD (e.g., alexithymia, emotion dysregulation, impulsivity, pain). Neurobiological studies show that the neurotoxicity of alcohol affects various elements of the interoceptive system (especially the insula) at structural and functional levels, with differential short/long term impacts. Conversely, primary interoceptive impairments may promote alcohol consumption and foster the evolution towards addiction. Despite convincing evidence demonstrating that interoception impairment may be an important contributor to the development and course of AUD, only a few studies directly evaluated interoceptive abilities in AUD. The research shows that interoceptive accuracy, the objective component of interoception, is lower in AUD individuals, and is correlated with craving and emotion dysregulation. Interoceptive sensibility is in turn higher in AUD individuals compared to healthy controls. Moreover, there is evidence that therapy focused on improving the ability to sense signals from the body in addiction treatment is effective. However, important methodological limitations in interoceptive measures persist, and it is therefore necessary to further investigate the associations between interoception and AUD.

Abnormal brain activity in nonsuicidal self-injury: a coordinate-based activation likelihood meta-analysis of functional neuroimaging studies

Background

The high prevalence of nonsuicidal self-injury (NSSI) in youths demonstrates a substantial population-level burden on society. NSSI is often associated with emotional and social skill deficits. To date, several studies have aimed to identify the underlying neural mechanism of those deficits in NSSI by using functional magnetic resonance imaging (fMRI). However, their conclusions display poor consistency.

Objective

We aimed to conduct a meta-analysis using activation likelihood estimation (ALE) for fMRI data based on emotional and cognitive tasks to clarify the underlying neural processing deficits of NSSI.

Methods

We searched for MRI studies of NSSI in the PubMed, Cochrane, and Embase databases. We identified significant foci for the included studies and conducted two ALE meta-analyses as follows: (i) activation for the NSSI contrast healthy control group and (ii) deactivation for the NSSI contrast healthy controls. Considering the diverse sex composition of study participants and possible bias from one large sample study, we conducted sensitivity analyses for the meta-analysis.

Results

Nine studies comprising 359 participants were included, and the results demonstrated substantial activation in NSSI patients compared with healthy controls in two clusters located in the right medial frontal gyrus extending to the rostral anterior cingulate and the left inferior frontal gyrus extending to the insula.

Conclusions

The results suggest that individuals with NSSI show brain activity alterations that underpin their core symptoms, including poor emotional regulation and reward processing deficits. Our findings provide new insights into the neural mechanism of NSSI, which may serve as functional biomarkers for developing effective diagnosis and therapeutic interventions for these patients.

Social Support Effects on Neural Stress and Alcohol Reward Responses

Social support (SS), or having people to depend on during times of stress, may offer an emotional and neurological buffer to problem drinking. Specifically, SS may modulate reward and stress-related brain responses to mitigate perceptions of alcohol reward and stress. There is limited evidence, however, on this topic and specifically on brain networks that may modulate SS effects on stress and alcohol reward. Here we present a review of the current literature on this topic as well as data from a large community sample of 115 social drinkers. Findings from a novel fMRI task viewing alcohol cue, stress, and neutral images, in separate blocks, while providing ratings on subjective feelings of alcohol craving, stress, and arousal are included. Lower SS significantly predicted greater alcohol craving during alcohol cue and stress conditions, higher baseline levels of stress, and greater arousal in the alcohol cue, relative to neutral condition. Remarkably, individuals with low SS showed greater reward activation (ventral medial prefrontal cortex (VmPFC) and ventral striatum) during alcohol cue exposure, while those with high SS showed no such activation (p < 0.001, family wise error corrected at 0.05). Furthermore, individuals with lower SS showed greater stress circuit (VmPFC, dorsal striatum, and periaqueductal gray) activation not observed in the high SS groups. Both groups showed increased amygdala activation under stress condition. The findings support the notion that SS is a powerful modulator of stress response and reward motivation. High SS buffers neural and subjective stress responses, while low SS potentiates greater reward seeking with higher alcohol craving and greater brain activation during alcohol cue exposure. Previous research and current results suggest the need to further explore the role of SS in those at risk of developing alcohol use disorder and assess novel prevention strategies to boost SS in at-risk drinkers.

Gut Microbiota-Induced Changes in β-Hydroxybutyrate Metabolism Are Linked to Altered Sociability and Depression in Alcohol Use Disorder

Patients with alcohol use disorder (AUD) present with important emotional, cognitive, and social impairments. The gut microbiota has been recently shown to regulate brain functions and behavior but convincing evidence of its role in AUD is lacking. Here, we show that gut dysbiosis is associated with metabolic alterations that affect behavioral (depression, sociability) and neurobiological (myelination, neurotransmission, inflammation) processes involved in alcohol addiction. By transplanting the gut microbiota from AUD patients to mice, we point out that the production of ethanol by specific bacterial genera and the reduction of lipolysis are associated with a lower hepatic synthesis of β-hydroxybutyrate (BHB), which thereby prevents the neuroprotective effect of BHB. We confirm these results in detoxified AUD patients, in which we observe a persisting ethanol production in the feces as well as correlations among low plasma BHB levels and social impairments, depression, or brain white matter alterations.

Faux Pas Recognition and Executive Processes in Patients with Alcohol Use Disorder: Toward an Investigation of Interindividual Heterogeneity

OBJECTIVE

Impairment of executive functions (EF) has been documented for decades in patients with alcohol use disorders (AUD), while more recent studies have also reported impaired theory of mind. Both have been associated with negative outcomes, particularly a high risk of relapse. However, the interrelatedness of EF and theory of mind impairments remains subject to debate.

METHOD

About 19 AUD outpatients and 20 healthy controls (HC) were asked to complete measures of motor inhibition, mental flexibility, and updating to assess EF, and the faux pas test to assess theory of mind.

RESULTS

As expected, patients' mean performances on EF and faux pas measures were poorer than those of HC. Correlational analyses revealed that executive processes were differentially related to faux pas subscores. Additional single-case analyses corroborated the strong association between EF and faux pas interpretation, as patients with AUD mostly had congruent performances (i.e., both EF and faux pas impaired or both EF and faux pas preserved).

CONCLUSIONS

This study highlights the interrelatedness of EF and faux pas performances in AUD, but also emphasizes the incomplete overlap of the cognitive processes involved in these tasks, with heterogeneous patterns of association. Based on these findings, tailored cognitive rehabilitation programs that simultaneously target EF and faux pas recognition could be developed to favor patients' social inclusion and reduce the risk of relapse. Results also argue in favor of systematic screening for EF and theory of mind impairments among AUD patients.

An integrated multimodal model of alcohol use disorder generated by data-driven causal discovery analysis

Alcohol use disorder (AUD) has high prevalence and adverse societal impacts, but our understanding of the factors driving AUD is hampered by a lack of studies that describe the complex neurobehavioral mechanisms driving AUD. We analyzed causal pathways to AUD severity using Causal Discovery Analysis (CDA) with data from the Human Connectome Project (HCP; n = 926 [54% female], 22% AUD [37% female]). We applied exploratory factor analysis to parse the wide HCP phenotypic space (100 measures) into 18 underlying domains, and we assessed functional connectivity within 12 resting-state brain networks. We then employed data-driven CDA to generate a causal model relating phenotypic factors, fMRI network connectivity, and AUD symptom severity, which highlighted a limited set of causes of AUD. The model proposed a hierarchy with causal influence propagating from brain connectivity to cognition (fluid/crystalized cognition, language/math ability, & working memory) to social (agreeableness/social support) to affective/psychiatric function (negative affect, low conscientiousness/attention, externalizing symptoms) and ultimately AUD severity. Our data-driven model confirmed hypothesized influences of cognitive and affective factors on AUD, while underscoring that addiction models need to be expanded to highlight the importance of social factors, amongst others.

Anxiety during abstinence from alcohol: A systematic review of rodent and human evidence for the anterior insula's role in the abstinence network

Alcohol Use Disorder (AUD) is a chronic, relapsing disease that impacts almost a third of Americans. Despite effective treatments for attaining sobriety, the majority of patients relapse within a year, making relapse a substantial barrier to long-term treatment success. A major factor contributing to relapse is heightened negative affect that results from the combination of abstinence-related increases in stress-reactivity and decreases in reward sensitivity. Substantial research has contributed to the understanding of reward-related changes in AUD. However, less is known about anxiety during abstinence, a critical component of understanding addiction as anxiety during abstinence can trigger relapse. Most of what we know about abstinence-related negative affect comes from rodent studies which have identified key brain regions responsible for abstinence-related behaviors. This abstinence network is composed of brain regions that make up the extended amygdala: the nucleus accumbens (NAcc), the central nucleus of the amygdala (CeA), and the bed nucleus of the stria terminalis (BNST). More recently, emerging evidence from rodent and human studies suggests a fourth brain region, the anterior insula, might be part of the abstinence network. Here, we review current rodent and human literature on the extended amygdala's role in alcohol abstinence and anxiety, present evidence for the anterior insula's role in the abstinence network, and provide future directions for research to further elucidate the neural underpinnings of abstinence in humans. A better understanding of the abstinence network is critical toward understanding and possibly preventing relapse in AUD.

The brain under stress-A systematic review and activation likelihood estimation meta-analysis of changes in BOLD signal associated with acute stress exposure

Psychosocial stress is an omnipresent phenomenon whose neural correlates in humans are still poorly understood. Several paradigms have been developed to induce acute stress in fMRI settings, but it is unclear whether there is a global brain activation pattern related to psychosocial stress. To integrate the different neuronal activation patterns, we conducted an activation likelihood estimation analysis on 31 studies totaling 1279 participants. Studies used the ScanSTRESS, Montreal Imaging Stress Test, aversive viewing paradigm (AVP), Social-Evaluative Threat or Cyberball. The analysis revealed bilateral activation clusters comprising the claustrum, insula and inferior frontal gyrus. This indicates that exposure to psychosocial stress leads to activations in brain areas involved in affective processing and the endocrine stress response. Furthermore, in a systematic review, Cyberball and AVP presented themselves as outliers due to increased activation in motor areas and lack of induction of stress related activity changes, respectively. As different paradigms emphasize different dimensions of psychosocial stress such as social evaluation or performance pressure, future research is needed to identify differences between the paradigms.

Tackling heterogeneity: Individual variability of emotion decoding deficits in severe alcohol use disorder

BACKGROUND

Severe alcohol use disorder (SAUD) is associated with social cognition deficits. Patients with SAUD are impaired for the recognition of emotional facial expressions, particularly at early stages of abstinence. These deficits damage interpersonal relations and increase relapse risk. However, uncertainties still abound on their variation across emotions and on the heterogeneity of emotional impairments across patients. We addressed these questions by exploring how the deficit varies according to emotions' type/intensity and patients' heterogeneity.

METHODS

Sixty-five recently detoxified patients with SAUD and 65 matched healthy controls performed the Facial Emotion Recognition Test, assessing the ability to identify six emotions (anger, contempt, disgust, fear, happiness, sadness) displayed by morphed faces with various intensities. Accuracy scores and detection thresholds were collected for each emotion. Beyond group comparisons, multiple single-case analyses determined the percentage of patients presenting decoding deficits for each emotion.

RESULTS

When current depression and anxiety symptoms were controlled for, patients did not present a general emotion decoding deficit, but were rather characterized by specific deficits for disgust/contempt in accuracy, and for disgust in detection threshold scores. Single-case analyses showed that only a third of patients presented a clinically significant emotional deficit.

CONCLUSIONS

Patients with SAUD only present emotional decoding deficits for specific interpersonal emotions (disgust/contempt) when subclinical psychopathological states are controlled for, and show no general emotional impairment. This goes against the proposal of a generalized social cognition deficit in this population. This group effect moreover masks a massive heterogeneity across patients, which has implications at experimental and clinical levels.

Social exclusion reliably engages the default network: A meta-analysis of Cyberball

Social exclusion refers to the experience of being disregarded or rejected by others and has wide-ranging negative consequences for well-being and cognition. Cyberball, a game where a ball is virtually tossed between players, then leads to the exclusion of the research participant, is a common method used to examine the experience of social exclusion. The neural correlates of social exclusion remain a topic of debate, particularly with regards to the role of the dorsal anterior cingulate cortex (dACC) and the concept of social pain. Here we conducted a quantitative meta-analysis using activation likelihood estimation (ALE) to identify brain activity reliably engaged by social exclusion during Cyberball task performance (Studies = 53; total N = 1,817 participants). Results revealed consistent recruitment in ventral anterior cingulate and posterior cingulate cortex, inferior and superior frontal gyri, posterior insula, and occipital pole. No reliable activity was observed in dACC. Using a probabilistic atlas to define dACC, fewer than 15% of studies reported peak coordinates in dACC. Meta-analytic connectivity mapping suggests patterns of co-activation are consistent with the topography of the default network. Reverse inference for cognition associated with reliable Cyberball activity computed in Neurosynth revealed social exclusion to be associated with cognitive terms Social, Autobiographical, Mental States, and Theory of Mind. Taken together, these findings highlight the role of the default network in social exclusion and warns against interpretations of the dACC as a key region involved in the experience of social exclusion in humans.

Approach and Avoidance Behavior in Female Patients With Borderline Personality Disorder

Objectives

Borderline personality disorder (BPD) is portrayed by unstable relationships, fears of abandonment and heightened sensitivity to social rejection. Research has shown that these characteristics may lead to inappropriate social behavior including altered approach-avoidance behavior. However, it has remained unclear how social exclusion may affect approach-avoidance behavior in patients with BPD.

Design

We assessed social approach-avoidance behavior and the impact of social exclusion in a sample of 38 patients with BPD and 40 healthy control participants.

Methods

We used an explicit joystick-based approach-avoidance task (AAT) after playing a virtual ball-tossing game (Cyberball), which simulates the exclusion of the participant by two other players. In the AAT, participants were required to push or pull emotional stimuli, more specifically happy and angry facial expressions, with either direct or averted gaze direction.

Results

Patients with BPD approached happy stimuli less and showed overall less differential approach-avoidance behavior toward individuals expressing positive or negative facial emotions compared to healthy participants, who showed more approach behavior for happy compared to angry facial expressions. Moreover, borderline symptom severity correlated inversely with the AAT score for happy facial expressions and positively with subjective unpleasantness during social exclusion as well as rejection sensitivity. However, social exclusion did not influence approach-avoidance tendencies.

Conclusion

Patients with BPD showed altered approach-avoidance behavior, which might affect social interactions in the patient’s everyday lives and may therefore impede social interaction.

Hostile attributional bias in severe alcohol use disorder

Impairments in social cognition have been documented in severe alcohol use disorder (SAUD) over the past two decades. They have been linked with lower social functioning and poor treatment outcomes, illustrating their key role in the disorder. However, studies investigating social cognition in SAUD have largely focused on emotional decoding and theory of mind abilities, neglecting other important processes. We expand this line of research by exploring the association between SAUD and hostile attributional biases (i.e., the tendency to attribute hostile intentions to others), another clinically relevant subcomponent of social cognition. Thirty-five patients with SAUD and thirty-five matched healthy controls completed the short version of the Ambiguous Intentions Hostility Questionnaire, a validated measure assessing participants' perceived hostility, blame attribution and aggression in relation to vignettes depicting social situations with negative outcomes and ambiguous intent. Patients with SAUD attributed more hostile intentions to others than did healthy controls. Moreover, this hostile attributional bias was associated with increased interpersonal problems in SAUD, as measured through the Inventory of Interpersonal Problems. We thus evidence hostile attributional bias in SAUD and extend the growing literature on social cognition impairments in this population. Furthermore, these findings corroborate the recent proposal that patients with SAUD exhibit biases toward socially threatening information. The association between hostile attributional bias and interpersonal problems suggests that targeting this bias in treatment may reduce the relapse risk resulting from interpersonal deficits. Recommendations are made to further explore the clinical relevance of hostile attributional bias in SAUD.

The vicious circle of social exclusion and psychopathology: a systematic review of experimental ostracism research in psychiatric disorders

Social exclusion (ostracism) is a major psychosocial factor contributing to the development and persistence of psychiatric disorders and is also related to their social stigma. However, its specific role in different disorders is not evident, and comprehensive social psychology research on ostracism has rather focused on healthy individuals and less on psychiatric patients. Here, we systematically review experimental studies investigating psychological and physiological reactions to ostracism in different responses of psychiatric disorders. Moreover, we propose a theoretical model of the interplay between psychiatric symptoms and ostracism. A systematic MEDLINE and PsycINFO search was conducted including 52 relevant studies in various disorders (some of which evaluated more than one disorder): borderline personality disorder (21 studies); major depressive disorder (11 studies); anxiety (7 studies); autism spectrum disorder (6 studies); schizophrenia (6 studies); substance use disorders (4 studies); and eating disorders (2 studies). Psychological and physiological effects of ostracism were assessed with various experimental paradigms: e.g., virtual real-time interactions (Cyberball), social feedback and imagined scenarios. We critically review the main results of these studies and propose the overall concept of a vicious cycle where psychiatric symptoms increase the chance of being ostracized, and ostracism consolidates or even aggravates psychopathology. However, the specificity and stability of reactions to ostracism, their neurobiological underpinnings, determinants, and moderators (e.g., attachment style, childhood trauma, and rejection sensitivity) remain elusive.

Socio-affective processing biases in severe alcohol use disorders: Experimental and therapeutic perspectives

Previous literature has consistently reported socio-affective information processing impairments in patients with severe alcohol use disorder (SAUD). Some recent studies have also suggested that these patients might exhibit biases toward stimuli indicating social threat, such as angry or disgusted faces. Such biases have been largely documented in other psychopathological disorders like anxiety, where they play a critical role in the emergence and maintenance of the disorder. A comprehensive understanding of these biases in SAUD would thus deepen the understanding of interpersonal difficulties and relapse-related factors. However, to date, no study has directly explored these biases in SAUD. In order to initiate efforts to address this issue, we first review preliminary evidence supporting the hypothesis of biased processing of social threat in SAUD. Then, we identify possible pathways through which such biases might negatively impact the course of the disorder. Finally, we provide precise recommendations and available materials to develop research in this promising field, and underline the related theoretical and clinical perspectives.

Selective visual and crossmodal impairment in the discrimination of anger and fear expressions in severe alcohol use disorder

BACKGROUND

Severe alcohol use disorder (SAUD) is associated with impaired discrimination of emotional expressions. This deficit appears increased in crossmodal settings, when simultaneous inputs from different sensory modalities are presented. However, so far, studies exploring emotional crossmodal processing in SAUD relied on static faces and unmatched face/voice pairs, thus offering limited ecological validity. Our aim was therefore to assess emotional processing using a validated and ecological paradigm relying on dynamic audio-visual stimuli, manipulating the amount of emotional information available.

METHOD

Thirty individuals with SAUD and 30 matched healthy controls performed an emotional discrimination task requiring to identify five emotions (anger, disgust, fear, happiness, sadness) expressed as visual, auditory, or auditory-visual segments of varying length. Sensitivity indices (d') were computed to get an unbiased measure of emotional discrimination and entered in a Generalized Linear Mixed Model. Incorrect emotional attributions were also scrutinized through confusion matrices.

RESULTS

Discrimination levels varied across sensory modalities and emotions, and increased with stimuli duration. Crucially, performances also improved from unimodal to crossmodal conditions in both groups, but discrimination for anger crossmodal stimuli and fear crossmodal/visual stimuli remained selectively impaired in SAUD. These deficits were not influenced by stimuli duration, suggesting that they were not modulated by the amount of emotional information available. Moreover, they were not associated with systematic emotional error patterns reflecting specific confusions between emotions.

CONCLUSIONS

These results clarify the nature and extent of crossmodal impairments in SAUD and converge with earlier findings to ascribe a specific role for anger and fear in this pathology.

Emotional and interpersonal deficits in alcohol-dependen A neuroscience perspective

The cerebral and cognitive consequences of alcohol-dependence have been widely explored during the last decades, but the emotional and interpersonal alterations associated with this psychiatric state have only been described recently. In view of the implication of these deficits in relapse after detoxification and of their omnipresence in clinical settings, there is an urgent need to further study these affective and social deficits presented by alcohol-dependent individuals. The present communication aims at offering a summary of the available empirical results on this topic and at underlining the usefulness of a multidisciplinary neuroscience approach to better understand these alterations. The initial studies, focusing on emotion decoding abilities, will first be described as they clearly established that alcohol-dependence is associated with a massive deficit in the identification of the emotional content of faces. The causal link between emotional alterations and alcohol-related problems will also be evoked, with a special focus on recent studies exploring the roots of alcohol-dependence. We will then show how more recent studies have capitalized on these first results to further explore affective and social abilities in alcohol-dependence, leading to the current development of a new research field: the affective and social neurosciences of alcohol-dependence, which combines neuroscience approaches by integrating neuropsychological, electrophysiological and neuroimaging techniques. Finally, we will identify the main fundamental and clinical perspectives in this field, and we will particularly insist on: (1) the need to take the emotional and social impairments into account in the new theoretical models of addictive states and; (2) the urgency to develop neuropsychological programs specifically dedicated to the rehabilitation of these deficits.

Neuroimaging Impaired Response Inhibition and Salience Attribution in Human Drug Addiction: A Systematic Review

The impaired response inhibition and salience attribution (iRISA) model proposes that impaired response inhibition and salience attribution underlie drug seeking and taking. To update this model, we systematically reviewed 105 task-related neuroimaging studies (n > 15/group) published since 2010. Results demonstrate specific impairments within six large-scale brain networks (reward, habit, salience, executive, memory, and self-directed networks) during drug cue exposure, decision making, inhibitory control, and social-emotional processing. Addicted individuals demonstrated increased recruitment of these networks during drug-related processing but a blunted response during non-drug-related processing, with the same networks also being implicated during resting state. Associations with real-life drug use, relapse, therapeutic interventions, and the relevance to initiation of drug use during adolescence support the clinical relevance of the results. Whereas the salience and executive networks showed impairments throughout the addiction cycle, the reward network was dysregulated at later stages of abuse. Effects were similar in alcohol, cannabis, and stimulant addiction.

Functional connectivity across social inclusion and exclusion is related to peer victimization and depressive symptoms in young adults

BACKGROUND

Peer victimization is associated with increased risk for depression, as well as increased neural response to social exclusion in the anterior cingulate cortex (ACC) and the amygdala. Altered functional connectivity (FxC) of fronto-limbic circuitry is associated with risk for various affective disorders. The present study examined the relationship between fronto-limbic FxC during social exclusion, prior peer victimization experience and depressive symptoms.

METHODS

Three mutually exclusive groups were formed: peer victimized (with a history of peer victimization), defenders (history of defending peers), and controls (no prior peer victimization experience) (n = 15/group; M_age = 17.7 years). Functional Magnetic Resonance Imaging data were collected while participants completed the Cyberball paradigm (simulating the experience of social exclusion). FxC between the Medial Prefrontal Cortex (MPFC), ACC, right insula and left amygdala, was compared between groups and examined in relation to depressive symptoms.

RESULTS

Prior peer victimization experience was associated with differences in fronto-limbic FxC across social inclusion and exclusion. Defenders displayed distinct shifts in FxC across the transition from being included to excluded. Peer victimized individuals exhibited a unique pattern of amygdala-specific FxC during inclusive interaction with peers, and in the continuous FxC across inclusion and exclusion. FxC of the MPFC-amygdala across inclusion and exclusion moderated the relationship between peer victimization and depressive symptoms.

LIMITATIONS

Small sample size and cross-sectional design limit interpretation of the findings.

CONCLUSIONS

Peer victimized individuals who exhibit continuous positive FxC of the MPFC-left amygdala across inclusion and exclusion may be at greater risk for depressive symptoms.

Dehumanization of psychiatric patients: Experimental and clinical implications in severe alcohol-use disorders

Dehumanization, defined as the denial of one's membership to humanity, is a process repeatedly reported in extreme contexts (e.g., genocides) but also in everyday life interactions. Some antecedents of dehumanizing experiences (e.g., social exclusion, negative stereotypes) have been reported among patients presenting psychiatric disorders, but dehumanization's experience remains completely unexplored in addictive disorders. We propose a theoretical model and research agenda to overcome this limitation and to improve our understanding of dehumanization's experience in psychiatry, with a special focus on alcohol-related disorders. We also propose much-needed clinical avenues to reduce dehumanization in clinical contexts, centrally by (1) improving dehumanization awareness among medical workers; (2) reducing the need for healthcare workers to use dehumanization to alleviate professional exhaustion; and (3) optimizing medical training to increase empathy toward patients. Finally, some additional improvements are proposed to promote patient's choices, comfort, dignity, and ultimately humanity in hospitals.

Neural correlates of ostracism in transgender persons living according to their gender identity: a potential risk marker for psychopathology?

BACKGROUND

Stigmatization in society carries a high risk for development of psychopathology. Transgender persons are at particularly high risk for such stigmatization and social rejection by others. However, the neural correlates of ostracism in this group have not been captured.

METHOD

Twenty transgender men (TM, female-to-male) and 19 transgender women (TW, male-to-female) already living in their gender identity and 20 cisgender men (CM) and 20 cisgender women (CW) completed a cyberball task assessing both exclusion and re-inclusion during functional magnetic resonance imaging (fMRI).

RESULTS

During psychosocial stress between-group differences were found in the dorsal and ventral anterior cingulate cortex (ACC) and the inferior frontal gyrus (IFG). Patterns were consistent with sex assigned at birth, i.e. CW showed greater activation in dorsal ACC and IFG relative to CM and TW. During re-inclusion, transgender persons showed greater ventral ACC activity relative to CW, possibly indicating persistent feelings of exclusion. Functional connectivity analyses supported these findings but showed a particularly altered functional connectivity between ACC and lateral prefrontal cortex in TM, which may suggest reduced emotional regulation to the ostracism experience in this group. Depressive symptoms or hormonal levels were not associated with these findings.

CONCLUSION

The results bear implications for the role of social exclusion in development of mental health problems in socially marginalized groups.

Insula Sensitivity to Unfairness in Alcohol Use Disorder

Aims

Social decision making has recently been evaluated in alcohol use disorder (AUD) using the ultimatum game (UG) task, suggesting a possible deficit in aversive emotion regulation elicited by the unfairness during this task. Despite the relevance to relapse of this possible faulty regulation, the brain correlates of the UG in AUD are unknown.

Methods

In total, 23 AUD and 27 healthy controls (HC) played three consecutive fMRI runs of the UG, while behavioral and brain responses were recorded.

Results

Overall, acceptance rate of unfair offers did not differ between groups, but there was a difference in the rate of behavioral change across runs. We found significant anterior insula (aINS) activation in both groups for both fair and unfair conditions, but only HC showed a trend towards increased activation during unfair vs. fair offers. There were not overall whole-brain between-group significant differences. We found a trend of signal attenuation, instead of an increase, in the aINS for AUD when compared to HC during the third run, which is consistent with our recent findings of selective insula atrophy in AUD.

Conclusion

We found differential group temporal dynamics of behavioral response in the UG. The HC group had a low acceptance rate for unfair offers in the first two runs that increased markedly for the third run; whereas the AUD group was consistent in their rejection of unfair offers across the three runs. We found a strong significant decrease in neural response across runs for both groups.

Short summary

This fMRI study of UG in alcohol use disorder found behavioral group differences in acceptance rate across runs, which together with significant BOLD-signal decrease across runs in UG-related regions in both groups, highlights the impairment of strategy in AUD and the effect of repetitive exposure to unfairness in this task.

Immediate and delayed neuroendocrine responses to social exclusion in males and females

Social exclusion is a complex phenomenon, with wide-ranging immediate and delayed effects on well-being, hormone levels, brain activation and motivational behavior. Building upon previous work, the current fMRI study investigated affective, endocrine and neural responses to social exclusion in a more naturalistic Cyberball task in 40 males and 40 females. As expected, social exclusion elicited well-documented affective and neural responses, i.e., increased anger and distress, as well as increased exclusion-related activation of the anterior insula, the posterior-medial frontal cortex and the orbitofrontal cortex. Cortisol and testosterone decreased over the course of the experiment, whereas progesterone showed no changes. Hormone levels were not correlated with subjective affect, but they were related to exclusion-induced neural responses. Exclusion-related activation in frontal areas was associated with decreases in cortisol and increases in testosterone until recovery. Given that results were largely independent of sex, the current findings have important implications regarding between-sex vs. within-sex variations and the conceptualization of state vs. trait neuroendocrine functions in social neuroscience.

Effects of Rifaximin on Central Responses to Social Stress-a Pilot Experiment

Probiotics that promote the gut microbiota have been reported to reduce stress responses, and improve memory and mood. Whether and how antibiotics that eliminate or inhibit pathogenic and commensal gut bacteria also affect central nervous system functions in humans is so far unknown. In a double-blinded randomized study, 16 healthy volunteers (27.00 ± 1.60 years; 9 males) received either rifaximin (600 mg/day) (a poorly absorbable antibiotic) or placebo for 7 days. Before and after the drug intervention, brain activities during rest and during a social stressor inducing feelings of exclusion (Cyberball game) were measured using magnetoencephalography. Social exclusion significantly affected (p < 0.001) mood and increased exclusion perception. Magnetoencephalography showed brain regions with higher activations during exclusion as compared to inclusion, in different frequency bands. Seven days of rifaximin increased prefrontal and right cingulate alpha power during resting state. Low beta power showed an interaction of intervention (rifaximin, placebo) × condition (inclusion, exclusion) during the Cyberball game in the bilateral prefrontal and left anterior cingulate cortex. Only in the rifaximin group, a decrease (p = 0.004) in power was seen comparing exclusion to inclusion; the reduced beta-1 power was negatively correlated with a change in the subjective exclusion perception score. Social stress affecting brain functioning in a specific manner is modulated by rifaximin. Contrary to our hypothesis that antibiotics have advert effects on mood, the antibiotic exhibited stress-reducing effects similar to reported effects of probiotics (supported by NeuroGUT, a EU 7th Framework Programme ITN no. 607652; ClinicalTrials.gov identifier number NCT02793193).

Prone to feel guilty: Self-evaluative emotions in alcohol-dependence

BACKGROUND

Prior research has repeatedly shown that alcohol-dependence is associated with interpersonal difficulties. However, guilt and shame, two crucial self-evaluative emotions triggered by the transgression of social norms, have not been explored among alcohol-dependent individuals despite their important role in psychiatric disorders. The present study thus aimed to investigate whether alcohol-dependence is associated with greater proneness to negatively evaluate one's own behaviors (guilt) or the entire self (shame).

METHODS

25 alcohol-dependent individuals (ADI) and 25 matched healthy individuals completed a scenario-based inventory (TOSCA-3), requiring from participants to rate the extent they will react to each scenario in terms of (contextualized) guilt and shame. Participants also completed a list of adjectives related to the frequency at which they generally experience (uncontextualized) guilt and shame (PFQ-2).

RESULTS

When controlling for possible confounds (i.e., depression and anxiety), ADI reported greater proneness to experience guilt at the TOSCA-3 (η²=.22) compared to healthy individuals.

CONCLUSIONS

This study is the first to show that alcohol-dependence is associated with greater contextualized guilt-proneness, i.e., negative evaluation of one's own behaviors that transgress social norms. Therefore, these results reinforce the relevance of social disorders in alcohol-dependence and indicate that ADI may benefit of therapeutic programs to avoid a generalization of guilt towards shame.

Dull to Social Acceptance Rather than Sensitivity to Social Ostracism in Interpersonal Interaction for Depression: Behavioral and Electrophysiological Evidence from Cyberball Tasks

Objectives: Impairments in interpersonal relationships in depression present as irritability, pessimism, and withdrawal, and play an important role in the onset and maintenance of the disorder. However, we know little about the neurological causes of this impaired interpersonal function. This study used the event-related brain potential (ERP) version of the Cyberball paradigm to investigate the emotions and neural activities in depressive patients during social inclusion and exclusion simultaneously to explore neuropsychological mechanisms.

Methods: Electrophysiological data were recorded when 27 depressed patients and 23 healthy controls (HCs) performed a virtual ball tossing game (Cyberball) during which the participants believed they were playing with two other co-players over the internet. The Cyberball paradigm included two other conditions; inclusion during which participants received the ball with the same probability as the other players to experience a feeling of acceptance, and exclusion during which the participants experienced a feeling of ostracism when the other two players threw the ball with each other. The Positive and Negative Affect Schedule (PANAS) was used as a baseline and after each block during the Cyberball to assess positive and negative effects. In addition, a brief Need-Threat Scale (NTS) was used to assess the fulfillment of basic needs of subjects after each block and 10 min after ostracism. Moreover, the relationship between the ERP data of depression and clinical symptoms was analyzed.

Results: Exclusion compared to inclusion Cyberball caused a decrease in positive affect and an increase in negative affect. The group differences were only found in the positive affect. Moreover, patients reported a lower level of basic needs than did HCs after social inclusion, but a similar level of basic needs after social exclusion. At the electrophysiological level, patients showed decreased P3 amplitudes compared to HCs in social inclusion, and P3 amplitudes were borderline negatively correlated with their scores of anhedonia symptoms.

Limitations: A limitation of our study was that the subjects' criteria were different.

Conclusions: The behavioral and electrophysiological results indicated that the interpersonal problems in depressive patients were mainly due to deficits in processing the pleasurable social stimuli rather than aversive social cues.

Correlates of Social Exclusion in Social Anxiety Disorder: An fMRI study

Cognitive models posit that social anxiety disorder (SAD) is maintained by biased information-processing vis-à-vis threat of social exclusion. However, uncertainty still abounds regarding the very nature of this sensitivity to social exclusion in SAD. Especially, brain alterations related to social exclusion have not been explored in SAD. Our primary purpose was thus to determine both the self-report and neural correlates of social exclusion in this population. 23 patients with SAD and 23 matched nonanxious controls played a virtual game (“Cyberball”) during fMRI recording. Participants were first included by other players, then excluded, and finally re-included. At the behavioral level, patients with SAD exhibited significantly higher levels of social exclusion feelings than nonanxious controls. At the brain level, patients with SAD exhibited significantly higher activation within the left inferior frontal gyrus relative to nonanxious controls during the re-inclusion phase. Moreover, self-report of social exclusion correlates with the activity of this cluster among individuals qualifying for SAD diagnosis. Our pattern of findings lends strong support to the notion that SAD may be better portrayed by a poor ability to recover following social exclusion than during social exclusion per se. These findings value social neuroscience as an innovative procedure to gain new insight into the underlying mechanisms of SAD.

Neural correlates of social exclusion across ages: A coordinate-based meta-analysis of functional MRI studies

Given the recent surge in functional neuroimaging studies on social exclusion, the current study employed activation likelihood estimation (ALE) based meta-analyses to identify brain regions that have consistently been implicated across different experimental paradigms used to investigate exclusion. We also examined the neural correlates underlying Cyberball, the most commonly used paradigm to study exclusion, as well as differences in exclusion-related activation between developing (7-18 years of age, from pre-adolescence up to late adolescence) and emerging adult (broadly defined as undergraduates, including late adolescence and young adulthood) samples. Results revealed involvement of the bilateral medial prefrontal and posterior cingulate cortices, right precuneus and left ventrolateral prefrontal cortex across the different paradigms used to examine social exclusion; similar activation patterns were identified when restricting the analysis to Cyberball studies. Investigations into age-related effects revealed that ventrolateral prefrontal activations identified in the full sample were driven by (i.e. present in) developmental samples, while medial prefrontal activations were driven by emerging adult samples. In addition, the right ventral striatum was implicated in exclusion, but only in developmental samples. Subtraction analysis revealed significantly greater activation likelihood in striatal and ventrolateral prefrontal clusters in the developmental samples as compared to emerging adults, though the opposite contrast failed to identify any significant regions. Findings integrate the knowledge accrued from functional neuroimaging studies on social exclusion to date, highlighting involvement of lateral prefrontal regions implicated in regulation and midline structures involved in social cognitive and self-evaluative processes across experimental paradigms and ages, as well as limbic structures in developing samples specifically.

What are Probable Olfactory Markers of Alcohol Dependence?

As the olfactory system is closely connected with the brain areas responsible for the most crucial alterations in psychiatric populations, especially cognitive and emotional impairments, the study of olfactory processing may be a relevant approach to identify specific markers of alcohol dependence. The aim of this study was to propose the probable olfactory markers for alcohol dependence through a study of the olfactory parameters that involve the central olfactory pathway. We recruited the same 41 alcohol-dependent patients in an early (day 8) and late (day 67) stage of abstinence and 41 controls matched for gender, age, and smoking status. The participants underwent clinical assessments and several olfactory evaluations. The results revealed on one hand, the persistence of decreased intensity of positive emotion (happy), increased intensity of negative emotion (sad), and increased citation of surprise in patients, suggesting the presence of probable trait markers of alcohol dependence. On the other hand, we found decreased hedonic score for pleasant and neutral odorants, and decreased odor familiarity judgment only in the early stage of evaluation as probable state markers for alcohol dependence. These results may be underpinned by several neuropsychological alterations specific to this disease and their evolution after weaning. Further studies are needed to replicate these findings and to confirm the specificity and sensitivity of the olfactory tests in a larger sample of patients. The olfactory perception of all controls must be also retested in order to determine the specific state and/or trait markers of alcohol dependence.