Effects of social exclusion and physical pain in chronic opioid maintenance treatment: fMRI correlates

Assessing pain in persons with opioid use disorder: Approaches, techniques and special considerations

Pain and opioid use disorder (OUD) are inextricably linked, as the former can be a risk factor for the development of the latter, and over a third of persons with OUD suffer concomitant chronic pain. Assessing pain among people with OUD is challenging, because ongoing opioid use brings changes in pain responses and most pain assessment tools have not been validated for this population. In this narrative review, we discuss the fundamentals of pain assessment for populations with OUD. First, we describe the biological, psychological and social aspects of the pain experience among people with OUD, as well as how opioid-related phenomena may contribute to the pain experience in this population. We then review methods to assess pain, including (1) traditional self-reported methods, such visual analogue scales and structured questionnaires; (2) behavioural observations and physiological indicators; (3) and laboratory-based approaches, such as quantitative sensory testing. These methods are considered from a perspective that encompasses both pain and OUD. Finally, we discuss strategies for improving pain assessment in persons with OUD and implications for future research, including educational strategies for multidisciplinary teams. We highlight the substantial gaps that persist in this literature, particularly regarding the applicability of current pain assessment methods to persons with OUD, as well as the generalizability of the existing results from adjacent populations on chronic opioid therapy but without OUD. As research linking pain and OUD evolves, considering the needs of diverse populations with complex psychosocial backgrounds, clinicians will be better equipped to reduce these gaps.

Dissecting shared pain representations to understand their behavioral and clinical relevance

Accounts of shared representations posit that the experience of pain and pain empathy rely on similar neural mechanisms. Experimental research employing novel analytical and methodological approaches has made significant advances in both the identification and targeted manipulation of such shared experiences and their neural underpinnings. This revealed that painful experiences can be shared on different representational levels, from pain-specific to domain-general features, such as negative affect and its regulation. In view of direct links between such representations and social behaviors such as prosocial behavior, conditions characterized by aberrant pain processing may come along with heavy impairments in the social domain, depending on the affected representational level. This has wide potential implications in light of the high prevalence of pain-related clinical conditions, their management, and the overuse of pain medication. In this review and opinion paper, we aim to chart the path toward a better understanding of the link between shared affect and prosocial behavior.

The Brain Salience Network at the Intersection of Pain and Substance use Disorders: Insights from Functional Neuroimaging Research

Purpose of Review

The brain's salience network (SN), primarily comprising the anterior insula and anterior cingulate cortex, plays a key role in detecting salient stimuli and processing physical and socioemotional pain (e.g., social rejection). Mounting evidence underscores an altered SN in the etiology and maintenance of substance use disorders (SUDs). This paper aims to synthesize recent functional neuroimaging research emphasizing the SN's involvement in SUDs and physical/socioemotional pain and explore the therapeutic prospects of targeting the SN for SUD treatment.

Recent Findings

The SN is repeatedly activated during the experience of both physical and socioemotional pain. Altered activation within the SN is associated with both SUDs and chronic pain conditions, characterized by aberrant activity and connectivity patterns as well as structural changes. Among individuals with SUDs, functional and structural alterations in the SN have been linked to abnormal salience attribution (e.g., heightened responsiveness to drug-related cues), impaired cognitive control (e.g., impulsivity), and compromised decision-making processes. The high prevalence of physical and socioemotional pain in the SUD population may further exacerbate SN alterations, thus contributing to hindered recovery progress and treatment failure. Interventions targeting the restoration of SN functioning, such as real-time functional MRI feedback, neuromodulation, and psychotherapeutic approaches, hold promise as innovative SUD treatments.

Summary

The review highlights the significance of alterations in the structure and function of the SN as potential mechanisms underlying the co-occurrence of SUDs and physical/socioemotional pain. Future work that integrates neuroimaging with other research methodologies will provide novel insights into the mechanistic role of the SN in SUDs and inform the development of next-generation treatment modalities.

Distinct neural dynamics of the observed ostracism effect in decision-making under risk and ambiguity

Observational ostracism, as a form of social exclusion, can significantly affect human behavior. However, the effects of observed ostracism on risky and ambiguous decision-making and the underlying neural mechanisms remain unclear. This event-related potential study investigated these issues by involving participants in a wheel-of- fortune task, considering observed ostracism and inclusion contexts. The results showed that the cue-P3 component was more enhanced during the choice phase for risky decisions than for ambiguous decisions in the observed inclusion contexts but not in the observed ostracism contexts. During the outcome evaluation phase, feedback-related negativity amplitudes following both risky and ambiguous decisions were higher in the no-gain condition than in the gain condition in the observed inclusion context. In contrast, this effect was only observed following risky decisions in the observed ostracism context. The feedback-P3 component did not exhibit an observed ostracism effect in risky and ambiguous decision-making tasks. Risk levels further modulated the cue-P3 and feedback-related negativity components, while ambiguity levels further modulated the feedback-P3 components. These findings demonstrate a neural dissociation between risk and ambiguity decision-making during observed ostracism that unfolds from the choice phase to the outcome evaluation phase.

The effect of social exclusion on pain perception and heart rate variability in healthy controls and somatoform pain patients

OBJECTIVES

The overlapping neural networks of social and physical pain have been investigated intensively in recent years. It was postulated that triggering social pain might result in greater physical pain. Nonetheless, how this affects somatoform pain disorder has not yet been considered. Since an increased pain processing activity is reported in these patients, the investigation of social exclusion and its effect on this group seems interesting. Hence, the aim of this study was to compare the influence of social exclusion on healthy controls and patients with somatoform pain disorder.

METHODS

Nineteen patients with somatoform pain disorder and 19 healthy controls were examined. Cyberball, a virtual ball-tossing paradigm, was used to experimentally induce social exclusion and inclusion. To measure effects on pain perception, pressure pain thresholds and heart rate variability (HRV) were recorded after each round of cyberball. Demographic data, pain medication, and potential psychosocial moderators were collected by questionnaires.

RESULTS

After social exclusion, pressure pain thresholds were significantly reduced in healthy controls (p < 0.01) as well as somatoform pain patients (p < 0.05), while HRV increased only in patients with somatoform pain disorder (p < 0.05) indicating increased parasympathetic activity.

CONCLUSION

This study is the first to analyse the effects of social exclusion on pain perception in somatoform pain disorder. While the reduction in pressure pain thresholds is in line with the social pain literature, the effects on HRV could be interpreted as a form of pain regulation mechanism. However, further research is needed to investigate the role of parasympathetic activity in socially excluded somatoform pain patients.

Associations between childhood ethnoracial minority density, cortical thickness, and social engagement among minority youth at clinical high-risk for psychosis

An ethnoracial minority density (EMD) effect in studies of psychotic spectrum disorders has been observed, whereby the risk of psychosis in ethnoracial minority group individuals is inversely related to the proportion of minorities in their area of residence. The authors investigated the relationships among area-level EMD during childhood, cortical thickness (CT), and social engagement (SE) in clinical high risk for psychosis (CHR-P) youth. Data were collected as part of the North American Prodrome Longitudinal Study. Participants included 244 ethnoracial minoritized (predominantly Hispanic, Asian and Black) CHR-P youth and ethnoracial minoritized healthy controls. Among youth at CHR-P (n = 164), lower levels of EMD during childhood were associated with reduced CT in the right fusiform gyrus (adjusted β = 0.54; 95% CI 0.17 to 0.91) and right insula (adjusted β = 0.40; 95% CI 0.05 to 0.74). The associations between EMD and CT were significantly moderated by SE: among youth with lower SE (SE at or below the median, n = 122), lower levels of EMD were significantly associated with reduced right fusiform gyrus CT (adjusted β = 0.72; 95% CI 0.29 to 1.14) and reduced right insula CT (adjusted β = 0.57; 95% CI 0.18 to 0.97). However, among those with greater SE (n = 42), the associations between EMD and right insula and fusiform gyrus CT were not significant. We found evidence that lower levels of ethnic density during childhood were associated with reduced cortical thickness in regional brain regions, but this association may be buffered by greater levels of social engagement.

Divergent emotional and autonomic responses to Cyberball in patients with opioid use disorder on opioid agonist treatment

The perception of social exclusion among patients with opioid use disorder (OUD) could be affected by long-term opioid use. This study explores the emotional and cardiac autonomic responses to an experience of ostracism in a sample of participants with OUD on opioid agonist treatment (OAT). Twenty patients with OUD and twenty healthy controls (HC) performed a ball-tossing game (Cyberball) with two conditions: Inclusion and Ostracism. We measured self-reported ratings of perceived threat towards one's fundamental needs and respiratory sinus arrhythmia (RSA) immediately after the game and 10 min after Ostracism (Reflective stage). Following ostracism, participants with OUD self-reported blunted feelings of threat to the fundamental need to belong. RSA levels were significantly suppressed immediately after ostracism and during the Reflective stage in comparison with HC, indicating an autonomic alteration in response to threatening social situations. Finally, only among HC higher perceived threats towards fundamental needs predicted increases in RSA levels, suggesting an adaptive vagal regulation in response to a perceived threat. Conversely, among patients with OUD the subjective response to ostracism was not associated with the autonomic reaction. OAT may have a protective effect against negative feelings of ostracism. However patients with OUD on OAT present poor autonomic regulation in response to social threats, which could reflect their trait hypersensitivity to social rejection.

Validation of the Perceived Phubbing Scale to the Argentine Context

In recent years, the increased use of mobile devices has changed social dynamics. One such change is the rise of phubbing, described as the behavior of ignoring someone in order to pay attention to one's cell phone. The purpose of this research was to validate the Perceived Phubbing Scale (PPS) and examine its relationship with other psychological variables. An Argentine sample was composed of 1608 participants aged between 18 and 65 (M = 45.59; SD 14.03), with 51.6% identifying as female. They were provided with a phubbing scale, along with scales to measure emotional disconnection, fear of missing out (FoMO) and social exclusion, and a sociodemographic questionnaire. The results indicated that the PPS showed an adequate fit to the data, based on a structure of one factor (X²₍₂₀₎ = 259.353, p < 0.001; CFI = 0.958; IFI = 0.958; RMSEA = 0.089) and the internal consistency (α = 0.93), resulting in a nine-item scale. Participants with high or medium levels of phubbing showed a tendency to suffer FoMO or feel socially excluded or socially isolated. We did not find differences in the levels of phubbing related to the participant's age, gender, or socioeconomic level. It is possible to conclude that PPS can be used as a reliable measure to evaluate perceived phubbing in Argentina. Implications of the variables studied are discussed as possible predictors of phubbing and are to be considered in its approach.

The influence of social signals on the self-experience of pain: A neuroimaging review

Researchers in cognitive neuroscience have investigated extensively how psychological factors shape the processing and perception of pain using behavioral, physiological, and neuroimaging methods. However, social influences of pain, an essential part of biopsychosocial pain models, have received relatively little attention. This is particularly true for the neurobiological mechanisms underlying social modulations on pain. Therefore, this review discusses the findings of recent neuroimaging studies measuring the effects of social manipulations on pain perception (e.g., verbal and non-verbal social signals, social interaction style, conformity, social support, and sociocultural mediators). Finally, a schematic summary of the different social modulatory themes is presented.

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.

Brain activation elicited by acute stress: An ALE meta-analysis

Stress abounds in daily life and is closely related to psychiatric disease. Less is known about the neural basis for the gender differences in stress, and the common and specific neural mechanism for physiological and psychosocial stress. The current study obtained 141 stress-oriented neuroimaging experiments from 126 eligible articles and sorted them into nine types of neuroimaging datasets based on the combination of stress (general, physiological or psychosocial) and gender (overall, male or female). An activation likelihood estimation (ALE) meta-analysis was conducted on each dataset to detect the spatial convergence of activations. A hierarchical clustering analysis was also conducted to uncover the relationship between the stress-induced paradigms and spatial distribution of brain activations. We found that the physiological stress and psychosocial stress showed common activation in the bilateral anterior insula and brainstem, but different activation likelihood in the bilateral insula, thalami, middle cingulate cortex, left fusiform gyri, and left amygdala. Men were more likely to activate the bilateral thalami during physiological stress, whereas women were more likely to activate the left amygdala during psychosocial stress. The activation patterns are more consistent among different physiological stress paradigms than psychosocial stress paradigms. Our results suggest that physiological stress and psychosocial stress activate common brain regions for movement and attentional regulation but different brain regions for sensory and affective processing.

HIV-1 Tat and morphine decrease murine inter-male social interactions and associated oxytocin levels in the prefrontal cortex, amygdala, and hypothalamic paraventricular nucleus

Many persons infected with HIV-1 (PWH) and opioid-dependent individuals experience deficits in sociability that interfere with daily living. Sociability is regulated by the prefrontal cortico-hippocampal-amygdalar circuit. Within this circuit HIV-1 trans-activator of transcription (HIV-1 Tat) and opioids can increase dendritic pathology and alter neuronal firing. Changes in sociability are also associated with dysregulation of hypothalamic neuropeptides such as oxytocin or corticotropin releasing factor (CRF) in the prefrontal cortico-hippocampal-amygdalar circuit. Accordingly, we hypothesized that the interaction of HIV-1 Tat and morphine would impair inter-male social interactions and disrupt oxytocin and CRF within the PFC and associated circuitry. Male mice were exposed to HIV-1 Tat for 8 weeks and administered saline or escalating doses of morphine twice daily (s.c.) during the last 2 weeks of HIV-1 Tat exposure. Tat attenuated aggressive interactions with an unknown intruder, whereas morphine decreased both non-aggressive and aggressive social interactions in the resident-intruder test. However, there was no effect of Tat or morphine on non-reciprocal interactions in the social interaction and novelty tests. Tat, but not morphine, decreased oxytocin levels in the PFC and amygdala, whereas both Tat and morphine decreased the percentage of oxytocin-immunoreactive neurons in the hypothalamic paraventricular nucleus (PVN). In Tat(+) or morphine-exposed mice, regional levels of CRF and oxytocin correlated with alterations in behavior in the social interaction and novelty tests. Overall, decreased expression of oxytocin in the prefrontal cortico-hippocampal-amygdalar circuit is associated with morphine- and HIV-Tat-induced deficits in social behavior.

Social exclusion increases the executive function of attention networks

Previous studies in humans have shown that brain regions activating social exclusion overlap with those related to attention. However, in the context of social exclusion, how does behavioral monitoring affect individual behavior? In this study, we used the Cyberball game to induce the social exclusion effect in a group of participants. To explore the influence of social exclusion on the attention network, we administered the Attention Network Test (ANT) and compared results for the three subsystems of the attention network (orienting, alerting, and executive control) between exclusion (N = 60) and inclusion (N = 60) groups. Compared with the inclusion group, the exclusion group showed shorter overall response time and better executive control performance, but no significant differences in orienting or alerting. The excluded individuals showed a stronger ability to detect and control conflicts. It appears that social exclusion does not always exert a negative influence on individuals. In future research, attention to network can be used as indicators of social exclusion. This may further reveal how social exclusion affects individuals' psychosomatic mechanisms.

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.

The Neural Processes Interlinking Social Isolation, Social Support, and Problem Alcohol Use

BACKGROUND

Subjective feeling of social isolation, as can be measured by perceived burdensomeness (PB), is a major risk factor for alcohol misuse. Heightened PB is associated with elevated stress response and diminished cognitive control, both of which contribute to problem drinking. Here, we sought to identify the neural substrates underlying the relationship between PB and alcohol misuse.

METHODS

We employed resting-state functional magnetic resonance imaging data collected from 61 problem drinkers to characterize the functional connectivity of the hypothalamus and ventral striatum (VS) in relation to PB. We specifically examined whether the connectivities of the hypothalamus and VS were differentially influenced by PB to produce contrasting effects on alcohol use. Finally, we evaluated how individual differences in social support modulate the inter-relationships of social isolation, neural connectivity, and the severity of problem drinking.

RESULTS

Whole-brain multiple regressions show a positive relationship between PB and hypothalamic connectivity with the hippocampus and an inverse pattern for VS connectivity with the middle frontal gyrus. Difference in strength between the 2 connectivities predicted the severity of problem drinking, suggesting an imbalance involving elevated hypothalamic and diminished prefrontal cortical modulation in socially isolated problem drinkers. A path analysis further revealed that the lack of social support was associated with a bias toward low prefrontal connectivity, which in turn increased PB and facilitated problem drinking.

CONCLUSIONS

Altered hypothalamus and VS connectivity may underlie problem drinking induced by social isolation. The current findings also highlight the important role of social support as a potential protective factor against alcohol misuse.

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.

Higher Social Rejection Sensitivity in Opioid-Dependent Patients Is Related to Smaller Insula Gray Matter Volume: A Voxel-Based Morphometric Study

Opioid-dependent patients are highly sensitized to negative social feedback, and increased social rejection sensitivity was linked to adverse treatment outcome, but its neurobiological underpinnings have not been understood yet. The present study investigated gray matter (GM) volume differences between 19 opioid maintenance treatment (OMT) patients and 20 healthy controls using magnetic resonance imaging and voxel-based morphometry. Associations of GM volumes with subjective feelings of exclusion and inclusion during a social ostracism (Cyberball) paradigm, with rejection sensitivity, social interaction anxiety and social phobia were explored. OMT patients displayed smaller GM volume in the bilateral insula and inferior frontal gyri. Psychometric and task data showed that patients reported significantly higher rejection sensitivity, social anxiety and social phobia scores and felt more excluded and less included during the social ostracism paradigm. Smaller GM volume in the insula was associated with higher subjective exclusion, lower subjective inclusion and higher rejection sensitivity, social anxiety and social phobia scores. Findings indicate that structural deficits in emotion- and anxiety-processing brain regions in OMT patients are associated with increased social rejection sensitivity. As social rejection is a potential trigger for relapse, patients might benefit from therapeutic strategies that promote social integration.