Antidepressant treatment, not depression, leads to reductions in behavioral and neural responses to pain empathy

Laurent R, Pomrenze MB, Boroon P, Heifets B, Smith M, Malenka RC. MDMA enhances empathy-like behaviors in mice via 5-HT release in the nucleus accumbens

MDMA (3,4-methylenedioxymethamphetamine) is a psychoactive drug with powerful prosocial effects. While MDMA is sometimes termed an "empathogen," empirical studies have struggled to clearly demonstrate these effects or pinpoint underlying mechanisms. Here, we paired the social transfer of pain and analgesia-behavioral tests modeling empathy in mice-with region-specific neuropharmacology, optogenetics, and transgenic manipulations to explore MDMA's action as an empathogen. We report that MDMA, given intraperitoneally or infused directly into the nucleus accumbens (NAc), robustly enhances the social transfer of pain and analgesia. Optogenetic stimulation of 5-HT release in the NAc recapitulates the effects of MDMA, implicating 5-HT signaling as a core mechanism. Last, we demonstrate that systemic MDMA or optogenetic stimulation of NAc 5-HT inputs restores deficits in empathy-like behaviors in the Shank3-deficient mouse model of autism. These findings demonstrate enhancement of empathy-related behaviors by MDMA and implicate 5-HT signaling in the NAc as a core mechanism mediating MDMA's empathogenic effects.

Negative emotionality downregulation affects moral choice but not moral judgement of harm: a pharmacological study

Previous neuroscientific research has expounded on the fundamental role played by emotion during moral decision-making. Negative emotionality has been observed to exert a general inhibitory effect towards harmful behaviors against others. Nevertheless, the downregulation of negative affects at different levels of moral processing (e.g. impersonal versus personal moral dilemmas) alongside its possible interactions with other factors (e.g. perspective taking) hasn't been directly assessed; both of which can assist in predicting future moral decision-making. In the present research, we empirically test (Study 1, N = 41) whether downregulating negative emotionality through pharmacological interventions using lorazepam (a GABA receptor agonist), modulate the permissibility of harm to others -i.e. if participants find it more morally permissible to harm others when harm is unavoidable (inevitable harm moral dilemmas), than when it may be avoided (evitable harm moral dilemmas). Furthermore, using another sample (Study 2, N = 31), we assess whether lorazepam's effect is modulated by different perspective-taking conditions during a moral dilemma task -e.g. "is it morally permissible for you to […]?" (1st person perspective), relative to "is it morally permissible for [x individual] to […]?" (3rd person perspective)-, where the outcome of the different scenarios is controlled. The results of both studies converge, revealing an emotion-dependent, rather than an outcome-dependent, pharmacological modulation. Lorazepam only influenced interpersonal moral judgments when not modulated by the evitable/inevitable condition. Furthermore, there was a significant interaction between perspective-taking and drug administration, as lorazepam exerted a larger effect in modulating moral choices rather than moral judgements.

How does feeling pain look like in depression: A review of functional neuroimaging studies

INTRODUCTION

Major Depression Disorder (MDD) and pain appear to be reciprocal risk factors and sharing common neuroanatomical pathways and biological substrates. However, the role of MDD on pain processing remains still unclear. Therefore, this review aims to focus on the effect of depression on pain anticipation, and perception, before and after treatment, through functional magnetic resonance imaging (fMRI).

METHODS

A bibliographic search was conducted on PubMed, Scopus and Web of Science, looking for fMRI studies exploring pain processing in MDD patients.

RESULTS

Amongst the 602 studies retrieved, 12 met the inclusion criteria. In terms of pain perception, studies evidenced that MDD patients generally presented increased activation in brain regions within the prefrontal cortex, insula and in the limbic system (such as amygdala, hippocampus) and occipital cortex. The studies investigating the effect of antidepressant treatment evidenced a reduced activation in areas such as insula, anterior cingulate, and prefrontal cortices. In terms of pain anticipation, contrasting results were evidenced in MDD patients, which presented both increased and decreased activity in the prefrontal cortex, the insula and the temporal lobe, alongside with increased activity in the anterior cingulate cortex, the frontal gyrus and occipital lobes.

LIMITATIONS

The small number of included studies, the heterogeneous approaches of the studies might limit the conclusions of this review.

CONCLUSIONS

Acute pain processing in MDD patients seems to involve numerous and different brain areas. However, more specific fMRI studies with a more homogeneous population and rigorous approach should be conducted to better highlight the effect of depression on pain processing.

Aberrant Resting-State Functional Connectivity in MDD and the Antidepressant Treatment Effect-A 6-Month Follow-Up Study

BACKGROUND

The mechanism by which antidepressants normalizing aberrant resting-state functional connectivity (rsFC) in patients with major depressive disorder (MDD) is still a matter of debate. The current study aimed to investigate aberrant rsFC and whether antidepressants would restore the aberrant rsFC in patients with MDD.

METHODS

A total of 196 patients with MDD and 143 healthy controls (HCs) received the resting-state functional magnetic resonance imaging and clinical assessments at baseline. Patients with MDD received antidepressant treatment after baseline assessment and were re-scanned at the 6-month follow-up. Network-based statistics were employed to identify aberrant rsFC and rsFC changes in patients with MDD and to compare the rsFC differences between remitters and non-remitters.

RESULTS

We identified a significantly decreased sub-network and a significantly increased sub-network in MDD at baseline. Approximately half of the aberrant rsFC remained significantly different from HCs after 6-month treatment. Significant overlaps were found between baseline reduced sub-network and follow-up increased sub-network, and between baseline increased sub-network and follow-up decreased sub-network. Besides, rsFC at baseline and rsFC changes between baseline and follow-up in remitters were not different from non-remitters.

CONCLUSIONS

Most aberrant rsFC in patients with MDD showed state-independence. Although antidepressants may modulate aberrant rsFC, they may not specifically target these aberrations to achieve therapeutic effects, with only a few having been directly linked to treatment efficacy.

Effects of Concomitant Benzodiazepines and Antidepressants Long-Term Use on Social Decision-Making: Results From the Ultimatum Game

Benzodiazepines and antidepressants have been shown to change responses to unfairness; however, the effects of their combined use on unfairness evaluation are unknown. This study examines the effects of concomitant benzodiazepines and antidepressants long-term use on the evaluation of fair and unfair offers. To analyze behavioral changes on responses to unfairness, we compared the performance of medicated participants and healthy controls in the Ultimatum Game (UG), both in the proposer and in the respondent role. The results showed that long-term psychotropic users had the worse economic strategy by accepting less offers than control subjects. However, in the proposer role, the unfair offers made by participants were similar between groups. The present results suggest that long-term use of psychotropic medication, specifically the combination of benzodiazepines and antidepressants, may increase the sensitivity to unfairness, resulting in higher rejection rates in conditions where this strategy is the most disadvantageous.

Neural changes in youth at high risk for bipolar disorder undergoing family-focused therapy or psychoeducation

BACKGROUND

Patients with mood disorders may benefit from psychosocial interventions through changes in brain networks underlying emotion processing. In this study, we used functional magnetic resonance imaging (fMRI) to investigate treatment-related changes in emotion processing networks in youth at familial high risk for bipolar disorder (BD).

METHODS

Youth, ages 9-17, were randomly assigned to family-focused therapy for high-risk youth (FFT-HR) or an active comparison treatment, Enhanced Care (EC). Before and after these 4-month treatments, participants underwent fMRI while viewing happy, fearful, and calm facial expressions. Twenty youth in FFT-HR and 20 in EC were included in analyses of pre- to post-treatment changes in activation across the whole brain. Significant clusters were assessed for correlation with mood symptom improvement.

RESULTS

In the dorsolateral prefrontal cortex (DLPFC), activation increased from pre- to post-treatment in the FFT-HR group and decreased in the EC group. Insula activation decreased in the FFT-HR group and did not change in the EC group. Across both treatments, decreasing activation in the hippocampus and amygdala was correlated with pre- to post-treatment improvement in hypomania, while increasing activation in the DLPFC was correlated with pre- to post-treatment improvement in depression.

DISCUSSION

Psychosocial treatment addresses abnormalities in emotion regulation networks in youth at high risk for BD. Increased prefrontal cortex activation suggests enhanced emotion regulation from pre- to post-treatment with FFT-HR. Improvements in family interactions may facilitate the development of prefrontal resources that provide protection against future mood episodes.

Ultra-high field imaging in Major Depressive Disorder: a review of structural and functional studies

BACKGROUND

Major depressive disorder (MDD) is a severe and pervasive psychiatric condition with a lifetime prevalence of 15-25%. Numerous Magnetic Resonance Imaging (MRI) studies employing scans at field strengths of 1.5T or 3T have been carried out in the last decades, providing an unprecedented insight into the neural correlates of MDD. However, in recent years, MRI technology has largely progressed and the use of scans at ultra-high field (≥ 7T) has improved the sensitivity and the resolution of MR images. In this context, with this review we aim to summarize evidence of structural and functional brain mechanisms underlying MDD obtained with ultra-high field MRI.

METHODS

We conducted a search on PubMed, Scopus and Web of Science of neuroimaging studies on MDD patients, which employed ultra-high field MRI. We detected six structural MRI studies, two Diffusion Tensor Imaging (DTI) studies and five functional MRI (fMRI) studies.

RESULTS

Overall, the MRI and DTI studies showed volumetric and structural connectivity alterations in the hippocampus and, to a lesser extent, in the amygdala. In contrast, more heterogeneous results were reported by fMRI studies, which, though, described functional abnormalities in the cingulate cortex, thalamus and several other brain areas.

LIMITATIONS

The small sample size and the heterogeneity in patients' samples, processing and study design limit the conclusion of the present review.

CONCLUSIONS

Studies employing scans at ultra-high magnetic field may provide a useful contribution to the mixed body of literature on MDD. This preliminary but promising evidence confirms the importance of performing ultra-high field MRI investigations in order to detect and better characterize subtle brain abnormalities in MDD.

Detached empathic experience of others' pain in remitted states of depression - An fMRI study

BACKGROUND

Major depressive disorder is strongly associated with impairments and difficulties in social interactions. Deficits in empathy, a vital skill for social interactions, have been identified as a risk factor for relapse. However, research on empathy in remitted states of depression is scarce. We chose a social neuroscience approach to investigate potentially altered neural processes involved in sub-components of empathy in remitted states of depression. We expected aberrations in cognitive components of empathy, based on previous reports regarding their role as risk factors for relapse.

METHODS

Employing functional magnetic resonance imaging and a pain empathy task (video clips of painful medical treatments), we compared behavioral and neural empathic responses of unmedicated remitted depressive patients (N = 32) to those of untreated acutely depressed patients (N = 29) and healthy controls (N = 35). Self-report ratings of pain evaluation and affect-sharing were obtained.

RESULTS

Compared to controls and acutely depressed patients, remitted depressive patients reported higher pain evaluation and showed increased activity in the right temporo-parietal junction. This region, which is central to self-other distinction and which has been linked to adopting a detached perspective, also exhibited reduced connectivity to the anterior insula. Furthermore, we observed reduced activity in regions involved in emotion processing (amygdala) and perception of affective facial expressions (fusiform face area, posterior superior temporal sulcus).

CONCLUSIONS

Remitted states of depression are associated with a detached empathic style in response to others' pain, characterized by increased self-other distinction, lowered affective processing, and reduced connectivity between empathy-related brain regions. Although this may prevent emotional harm in specific situations, it may reduce opportunities for positive experiences in social interactions in the long run.

Suffering and Salutogenesis: A Conceptual Analysis of Lessons for Psychiatry From Existential Positive Psychology (PP2.0) in the Setting of the COVID-19 Pandemic

The COVID-19 pandemic has had a widespread effect on the thoughts, emotions and behavior of millions of people all around the world. In this context, a large body of scientific literature examining the mental health impact of this global crisis has emerged. The majority of these studies have framed this impact in terms of pre-defined categories derived from psychiatric nosology, such as anxiety disorders, depression or post-traumatic stress disorder. These constructs often fail to capture the complexity of the actual experiences of the individuals being studied; more specifically, they describe these experiences exclusively in terms of disease, while neglecting their potentially adaptive or “salutogenic” aspects. Similarly, discussion of psychological assistance for these individuals has largely been confined to a reiteration of “evidence-based” psychological or pharmacological techniques which can be delivered using remote access technology. In the context of the COVID-19 pandemic, these approaches are likely to be of mixed efficacy. Conversely, “negative emotions” or distressing psychological experiences may actually be functional in the setting of a disaster or crisis, serving to minimize harm, maximize social coherence and compliance, and facilitate adherence to safety measures. The limitations of the “conventional” approach are, to a certain degree, inherent to the prevailing medical model of mental health. Beyond these considerations lies the concept of “salutogenesis,” a term which refers to the innate capacity of individuals to create and maintain health and well-being in the face of adversity. Using principles derived from the second wave of positive psychology (PP2.0), particularly its emphasis on the totality of human experience and the possibility of deriving meaning and character growth from suffering, this paper conceptually analyses the relevant aspects of salutogenesis and PP2.0, and proposes an alternate approach for addressing mental health concerns during the COVID-19 pandemic. Such an approach, while acknowledging the utility of the conventional medical-psychotherapeutic model in specific cases, reduces the risk of medicalizing human experience, and provides individuals and communities with opportunities for growth and adaptation. The benefits of this proposal could potentially extend far beyond the current crisis, offering an opportunity for the field of psychiatry and mental health research to move away from a purely “disease-centered” model.

Alterations in event-related potential responses to empathy for pain in Parkinson's disease on and off medication

OBJECTIVE

How Parkinson's disease (PD) affects an individual's empathic capacity remains poorly understood. By using the event-related potential (ERP) technique, we sought to: (1) study the temporal dynamics of empathic responses in patients with PD; (2) explore whether dopaminergic medication modulates empathic processing.

METHODS

Twenty-six patients with early-to-moderate PD (13 on- and 13 off-medication) and 14 healthy controls performed an empathy-for-pain paradigm test while we recorded their electroencephalography. The participants responded to neutral or painful pictures during an active empathic condition (pain judgment task) and a control condition that was manipulated by task demands (laterality judgment task).

RESULTS

The ERP results demonstrated an early automatic frontal response and a late controlled parietal response to pain in healthy elderly controls. The observed early and late ERP responses were detected in the on-medication patients but not in the off-medication patients.

CONCLUSIONS

PD is associated with deficits in both affective and cognitive empathic responses, dopaminergic medication may have the potential to alleviate these deficits.

SIGNIFICANCE

This study helps to understand empathic deficits in patients with PD. Within-subject studies are required to reliably assess the effect of dopaminergic medication on empathic processing.

Chronic non-medical prescription opioid use and empathy for pain: Does pain make the difference?

Non-medical prescription opioid use (NMPOU) is at the heart of the opioid epidemic in the United States. Although chronic opioid use is commonly accompanied by deficits in social functioning, little is known about the impact of chronic NMPOU on social cognitive functions. Social neuroscience models suggest that empathy activates similar or even equivalent neural structures as those underpinning the first-hand experience in that emotional state (e.g., pain). Therefore, we measured subjective and psychophysiological responses during an empathy-for-pain task in 23 individuals with NMPOU, objectively confirmed by hair and urine testing, and compared them with 29 opioid-naïve healthy controls. NMPOU individuals showed lower other-related and self-related unpleasantness ratings when seeing others in pain than controls. No differences between the control and NMPOU group were found in skin conductance responses and heart rate variability (HRV) assessed by root mean square of successive differences (RMSSD) in response to the task. However, RMSSD-HRV was strongly negatively correlated with self-related unpleasantness and craving in the NMPOU group. A subsequent mediation analysis showed a total effect of RMSSD-HRV on self-related unpleasantness with no mediation of craving. This indicates that stronger emotion regulation indexed by high RMSSD-HRV might have downregulating effects on sharing others' pain in NMPOU individuals but not in healthy controls, which was further accompanied by decreased ratings of personal distress and empathetic concern. These results contribute to a better understanding of social functioning in chronic opioid users, suggesting adequate emotion regulation and empathy trainings as therapeutic targets for future interventions of opioid use disorders and long-term pain treatment with opioids.

Cognitive and emotional empathy after stimulation of brain mineralocorticoid and NMDA receptors in patients with major depression and healthy controls

Mineralocorticoid receptors (MR) are predominantly expressed in the hippocampus and prefrontal cortex. Both brain areas are associated with social cognition, which includes cognitive empathy (ability to understand others' emotions) and emotional empathy (ability to empathize with another person). MR stimulation improves memory and executive functioning in patients with major depressive disorder (MDD) and healthy controls, and leads to glutamate-mediated N-methyl-D-aspartate receptor (NMDA-R) signaling. We examined whether the beneficial effects of MR stimulation can be extended to social cognition (empathy), and whether DCS would have additional beneficial effects. In this double-blind placebo-controlled single-dose study, we randomized 116 unmedicated MDD patients (mean age 34 years, 78% women) and 116 age-, sex-, and education years-matched healthy controls to four conditions: MR stimulation (fludrocortisone (0.4 mg) + placebo), NMDA-R stimulation (placebo + D-cycloserine (250 mg)), MR and NMDA-R stimulation (both drugs), or placebo. Cognitive and emotional empathy were assessed by the Multifaceted Empathy Test. The study was registered on clinicaltrials.gov (NCT03062150). MR stimulation increased cognitive empathy across groups, whereas NMDA-R stimulation decreased cognitive empathy in MDD patients only. Independent of receptor stimulation, cognitive empathy did not differ between groups. Emotional empathy was not affected by MR or NMDA-R stimulation. However, MDD patients showed decreased emotional empathy compared with controls but, according to exploratory analyses, only for positive emotions. We conclude that MR stimulation has beneficial effects on cognitive empathy in MDD patients and healthy controls, whereas NMDA-R stimulation decreased cognitive empathy in MDD patients. It appears that MR rather than NMDA-R are potential treatment targets to modulate cognitive empathy in MDD.

Changes in the neural correlates of self-blame following mindfulness-based cognitive therapy in remitted depressed participants

Mindfulness-Based-Cognitive-Therapy (MBCT) reduces vulnerability for relapse into depression by helping individuals to counter tendencies to engage in maladaptive repetitive patterns of thinking and respond more compassionately to negative self-judgment. However, little is known about the neural correlates underlying these effects. To elucidate these correlates, we investigated fMRI brain activation during a task eliciting feelings of blaming oneself or others. Sixteen participants in remission from major depressive disorder (MDD) completed fMRI assessments before and after MBCT, alongside self-reported levels of self-compassion, mindfulness, and depression symptoms. Analyses of self-blame versus other-blame contrasts showed a reduction in activation in the bilateral dorsal anterior cingulate/medial superior frontal gyrus after MBCT compared to baseline. Further, exploratory analyses showed that increases in self-kindness after MBCT correlated with reduced activation in the posterior cingulate cortex (PCC)/precuneus in self-blame versus rest contrasts. These findings suggest that MBCT is associated with a reduction in activations in cortical midline regions to self-blame which may be mediated by increasing self-kindness. However, this is a small, uncontrolled study with 16 participants and therefore our results will need confirmation in a controlled study.

Social Cognition and Interpersonal Problems in Persistent Depressive Disorder vs. Episodic Depression: The Role of Childhood Maltreatment

Objective: Little is known about the specific psychological features that differentiate persistent depressive disorder (PDD) and episodic depression (ED). Thus, the present study aimed to investigate differences in social cognition and interpersonal problems between these two forms of depression and healthy controls. In addition, we aimed to examine childhood maltreatment (CM) as a possible origin of these alterations. Methods: In a cross-sectional study, adult patients with a current PDD (n = 34) or in a current episode of ED (n = 38), and healthy controls (n = 39) completed questionnaires about depression severity, empathy, interpersonal problems, and CM, as well as tests of affective theory of mind and facial emotion recognition. Results: Patients with PDD reported higher empathic distress than patients with ED and healthy controls. Both depressive groups recognized angry faces with higher accuracy and reported more interpersonal problems, with no differences between PDD and ED. Empathic distress and interpersonal problems mediated the link between CM and depression in the combined sample. Limitations: Patient groups were not drug-naïve and antidepressant intake might have influenced social-cognitive functions. Self-report measures of empathy and interpersonal problems are vulnerable to bias. The cross-sectional design does not allow causal conclusions. Conclusion: Depressed patients may not show deficits in decoding the affective states of others and in feeling with others. However, depressed individuals-in particular patients with PDD-may feel easily overwhelmed by emotionally tense situations, resulting in empathic distress and avoidant/submissive interpersonal behavior. Exposure to CM might be an origin of alterations in social cognition and interpersonal problems.