Are you gonna leave me? Separation anxiety is associated with increased amygdala responsiveness and volume

How movies move us - movie preferences are linked to differences in neuronal emotion processing of fear and anger: an fMRI study

Introduction

As a source of audio-visual stimulation, movies expose people to various emotions. Interestingly, several genres are characterized by negative emotional content. Albeit theoretical approaches exist, little is known about preferences for specific movie genres and the neuronal processing of negative emotions.

Methods

We investigated associations between movie genre preference and limbic and reward-related brain reactivity to close this gap by employing an fMRI paradigm with negative emotional faces in 257 healthy participants. We compared the functional activity of the amygdala and the nucleus accumbens (NAcc) between individuals with a preference for a particular movie genre and those without such preference.

Results and discussion

Amygdala activation was relatively higher in individuals with action movie preference (p TFCE-FWE = 0.013). Comedy genre preference was associated with increased amygdala (p TFCE-FWE = 0.038) and NAcc activity (p TFCE-FWE = 0.011). In contrast, crime/thriller preference (amygdala: p TFCE-FWE ≤ 0.010, NAcc: p TFCE-FWE = 0.036), as well as documentary preference, was linked to the decreased amygdala (p TFCE-FWE = 0.012) and NAcc activity (p TFCE-FWE = 0.015). The study revealed associations between participants' genre preferences and brain reactivity to negative affective stimuli. Interestingly, preferences for genres with similar emotion profiles (action, crime/thriller) were associated with oppositely directed neural activity. Potential links between brain reactivity and susceptibility to different movie-related gratifications are discussed.

Persistence of amygdala hyperactivity to subliminal negative emotion processing in the long-term course of depression

Biased emotion processing has been suggested to underlie the etiology and maintenance of depression. Neuroimaging studies have shown mood-congruent alterations in amygdala activity in patients with acute depression, even during early, automatic stages of emotion processing. However, due to a lack of prospective studies over periods longer than 8 weeks, it is unclear whether these neurofunctional abnormalities represent a persistent correlate of depression even in remission. In this prospective case-control study, we aimed to examine brain functional correlates of automatic emotion processing in the long-term course of depression. In a naturalistic design, n = 57 patients with acute major depressive disorder (MDD) and n = 37 healthy controls (HC) were assessed with functional magnetic resonance imaging (fMRI) at baseline and after 2 years. Patients were divided into two subgroups according to their course of illness during the study period (n = 37 relapse, n = 20 no-relapse). During fMRI, participants underwent an affective priming task that assessed emotion processing of subliminally presented sad and happy compared to neutral face stimuli. A group × time × condition (3 × 2 × 2) ANOVA was performed for the amygdala as region-of-interest (ROI). At baseline, there was a significant group × condition interaction, resulting from amygdala hyperactivity to sad primes in patients with MDD compared to HC, whereas no difference between groups emerged for happy primes. In both patient subgroups, amygdala hyperactivity to sad primes persisted after 2 years, regardless of relapse or remission at follow-up. The results suggest that amygdala hyperactivity during automatic processing of negative stimuli persists during remission and represents a trait rather than a state marker of depression. Enduring neurofunctional abnormalities may reflect a consequence of or a vulnerability to depression.

Associations between early trajectories of amygdala development and later school-age anxiety in two longitudinal samples

Amygdala function is implicated in the pathogenesis of autism spectrum disorder (ASD) and anxiety. We investigated associations between early trajectories of amygdala growth and anxiety and ASD outcomes at school age in two longitudinal studies: high- and low-familial likelihood for ASD, Infant Brain Imaging Study (IBIS, n = 257) and typically developing (TD) community sample, Early Brain Development Study (EBDS, n = 158). Infants underwent MRI scanning at up to 3 timepoints from neonate to 24 months. Anxiety was assessed at 6-12 years. Linear multilevel modeling tested whether amygdala volume growth was associated with anxiety symptoms at school age. In the IBIS sample, children with higher anxiety showed accelerated amygdala growth from 6 to 24 months. ASD diagnosis and ASD familial likelihood were not significant predictors. In the EBDS sample, amygdala growth from birth to 24 months was associated with anxiety. More anxious children had smaller amygdala volume and slower rates of amygdala growth. We explore reasons for the contrasting results between high-familial likelihood for ASD and TD samples, grounding results in the broader literature of variable associations between early amygdala volume and later anxiety. Results have the potential to identify mechanisms linking early amygdala growth to later anxiety in certain groups.

RGS14 expression in CA2 hippocampus, amygdala, and basal ganglia: Implications for human brain physiology and disease

RGS14 is a multifunctional scaffolding protein that is highly expressed within postsynaptic spines of pyramidal neurons in hippocampal area CA2. Known roles of RGS14 in CA2 include regulating G protein, H-Ras/ERK, and calcium signaling pathways to serve as a natural suppressor of synaptic plasticity and postsynaptic signaling. RGS14 also shows marked postsynaptic expression in major structures of the limbic system and basal ganglia, including the amygdala and both the ventral and dorsal subdivisions of the striatum. In this review, we discuss the signaling functions of RGS14 and its role in postsynaptic strength (long-term potentiation) and spine structural plasticity in CA2 hippocampal neurons, and how RGS14 suppression of plasticity impacts linked behaviors such as spatial learning, object memory, and fear conditioning. We also review RGS14 expression in the limbic system and basal ganglia and speculate on its possible roles in regulating plasticity in these regions, with a focus on behaviors related to emotion and motivation. Finally, we explore the functional implications of RGS14 in various brain circuits and speculate on its possible roles in certain disease states such as hippocampal seizures, addiction, and anxiety disorders.

Brain responses to social cues of attachment in mid-childhood

Physical separation from caregivers activates attachment-related behaviors. However, neural underpinnings of this biological mechanism in humans and their development are poorly understood. We examined via functional MRI brain responses to pictorial representations of separation as a function of attachment-security, attachment-avoidance, and attachment-anxiety measured using the Child-Attachment-Interview, in 30 typically developing children (9-11 years). Attachment-related stimuli elicited enhanced activation in the precuneus, temporoparietal junction area, and medial superior frontal gyrus (described as mentalization network). More negatively rated attachment stimuli yielded increased activity in the inferior frontal gyrus/anterior insula and dorsal anterior cingulate cortex/ACC. Furthermore, ACC responses to attachment-related as compared to control stimuli were positively correlated with attachment-security and negatively correlated with attachment-avoidance. Our findings suggest that processing of separation cues elicits increased mentalization-related processing in children and activation of the salience network with increased negative valence of stimuli. Avoidant vs. securely attached children differentially activate ACC-dependent processes of affective evaluation.

Neuroimaging of human and non-human animal emotion and affect in the context of social relationships

Long-term relationships are essential for the psychological wellbeing of humans and many animals. Positive emotions and affective experiences (e.g., romantic or platonic love) seem to be closely related to the creation and maintenance of social bonds. When relationships are threatened or terminated, other emotions generally considered to be negative can arise (e.g., jealousy or loneliness). Because humans and animals share (to varying degrees) common evolutionary histories, researchers have attempted to explain the evolution of affect and emotion through the comparative approach. Now brain imaging techniques allow the comparison of the neurobiological substrates of affective states and emotion in human and animal brains using a common methodology. Here, we review brain imaging studies that feature emotions characterized by the context of social bonding. We compare imaging findings associated with affective and emotional states elicited by similar social situations between humans and animal models. We also highlight the role of key neurohormones (i.e., oxytocin, vasopressin, and dopamine) that jointly support the occurrence of socially contextualized emotions and affect across species. In doing so, we seek to explore and clarify if and how humans and animals might similarly experience social emotion and affect in the context of social relationships.

Emotion processing in depression with and without comorbid anxiety disorder

BACKGROUND

Among mental disorders, major depressive disorder (MDD) is highly prevalent and associated with emotional dysfunctions linked to activity alterations in the brain, mainly in prefrontal regions, the insula, the anterior cingulate cortex and the amygdala. However, this evidence is heterogeneous, perhaps because magnetic resonance imaging (MRI) studies on MDD tend to neglect comorbid anxiety (COM-A).

METHODS

To address this, here a sample of age- and sex-matched patients, n_MDD = 90 and n_COM-A = 85, underwent functional MRI to assess neurofunctional group differences during a negative emotional face-matching task using a hypothesis-driven region of interest approach (dorsolateral prefrontal cortex, insula, anterior cingulate cortex, amygdala) and an explorative whole-brain approach. We also assessed these relationships with state-trait anxiety measures, a state depression measure, general functioning and medication load.

RESULTS

During face processing, COM-A (compared to MDD) had significantly increased bilateral insula activity. No activity differences were found in the anterior cingulate cortex or the amygdala. Whole-brain analyses revealed increased inferior temporal activation and frontal activation (comprising the inferior and middle frontal gyrus) in COM-A that was positively linked to state anxiety as well as general functioning across groups.

LIMITATIONS

Still, the lack of a healthy control and small effects mean this study should be replicated to further interpret the results.

CONCLUSIONS

The findings highlight a discriminative activation pattern between MDD and COM-A regarding emotion processing and may present a correlate of potentially anxiety-related psychopathology. In future, further investigations in potential discriminative activity patterns could help to elucidate the origin, development and treatment of depression.

Changes in brain function during negative emotion processing in the long-term course of depression

BACKGROUND

Relapses in major depression are frequent and are associated with a high burden of disease. Although short-term studies suggest a normalisation of depression-associated brain functional alterations directly after treatment, long-term investigations are sparse.

AIMS

To examine brain function during negative emotion processing in association with course of illness over a 2-year span.

METHOD

In this prospective case-control study, 72 in-patients with current depression and 42 healthy controls were investigated during a negative emotional face processing paradigm, at baseline and after 2 years. According to their course of illness during the study interval, patients were divided into subgroups (n = 25 no-relapse, n = 47 relapse). The differential changes in brain activity were investigated by a group × time analysis of covariance for the amygdala, hippocampus, insula and at whole-brain level.

RESULTS

A significant relapse × time interaction emerged within the amygdala (P_TFCE-FWE = 0.011), insula (P_TFCE-FWE = 0.001) and at the whole-brain level mainly in the temporal and prefrontal cortex (P_TFCE-FWE = 0.027), resulting from activity increases within the no-relapse group, whereas in the relapse group, activity decreased during the study interval. At baseline, the no-relapse group showed amygdala, hippocampus and insula hypoactivity compared with healthy controls and the relapse group.

CONCLUSIONS

This study reveals course of illness-associated activity changes in emotion processing areas. Patients in full remission show a normalisation of their baseline hypo-responsiveness to the activation level of healthy controls after 2 years. Brain function during emotion processing could further serve as a potential predictive marker for future relapse.

Experimental evidence for a child-to-adolescent switch in human amygdala-prefrontal cortex communication: A cross-sectional pilot study

Interactions between the amygdala and prefrontal cortex are fundamental to human emotion. Despite the central role of frontoamygdala communication in adult emotional learning and regulation, little is known about how top-down control emerges during human development. In the present cross-sectional pilot study, we experimentally manipulated prefrontal engagement to test its effects on the amygdala during development. Inducing dorsal anterior cingulate cortex (dACC) activation resulted in developmentally-opposite effects on amygdala reactivity during childhood versus adolescence, such that dACC activation was followed by increased amygdala reactivity in childhood but reduced amygdala reactivity in adolescence. Bayesian network analyses revealed an age-related switch between childhood and adolescence in the nature of amygdala connectivity with the dACC and ventromedial PFC (vmPFC). Whereas adolescence was marked by information flow from dACC and vmPFC to amygdala (consistent with that observed in adults), the reverse information flow, from the amygdala to dACC and vmPFC, was dominant in childhood. The age-related switch in information flow suggests a potential shift from bottom-up co-excitatory to top-down regulatory frontoamygdala connectivity and may indicate a profound change in the circuitry supporting maturation of emotional behavior. These findings provide novel insight into the developmental construction of amygdala-cortical connections and implications for the ways in which childhood experiences may influence subsequent prefrontal function.

Individual Differences in Hemispheric Emotional Valence by Computerized Test Correlate with Lateralized Differences in Nucleus Accumbens, Hippocampal and Amygdala Volumes

Purpose

Conventional theories of hemispheric emotional valence (HEV) postulate fixed hemispheric differences in emotional processing. Schiffer’s dual brain psychology proposes that there are prominent individual differences with a substantial subset showing a reversed laterality pattern. He further proposed that hemispheric differences were more akin to differences in personality than in emotional processing. This theory is supported by findings that unilateral treatments, such as transcranial magnetic stimulation, are effective if they accurately target individual differences in laterality. The aim of this paper was to assess if a computer test of hemispheric emotional valence (CTHEV) could effectively identify individual differences in HEV and to ascertain if these individual differences were associated with underlying differences in brain structure and connectivity.

Patients and Methods

The CTHEV was administered to 50 (18 male/32 female) right-handed participants, aged 18–19 years, enrolled in a study assessing the neurobiological effects of childhood maltreatment. Based on a literature review, we determined whether CTHEV correlated with lateralized volumes of the nucleus accumbens, amygdala, hippocampus, and subgenual anterior cingulate as well as volume of the corpus callosum.

Results

CTHEV scores correlated with laterality indices of the nucleus accumbens (p = 0.00016), amygdala (p = 0.0138) and hippocampus (p = 0.031). A positive left hemispheric valence was associated with a larger left-sided nucleus accumbens and hippocampus and a smaller left amygdala. We identified four eigenvector network centrality DTI measures that predict CTHEV, most notably the left amygdala, and found that CTHEV results correlated with total and segment-specific corpus callosal volumes.

Conclusion

Individual differences in HEV can be readily assessed by computer test and correlate with differences in brain structure and connectivity that could provide a mechanistic understanding. These findings provide further support for a revised understanding of HEV and provide a tool that could be used to guide lateralized brain treatments.

Brain functional correlates of emotional face processing in body dysmorphic disorder

Previous neuroimaging studies in body dysmorphic disorder (BDD) have focused on discordances in visual processing systems. However, little is known about brain functional aberrations in individuals with BDD during emotional face processing. An fMRI paradigm with negative emotional faces was employed in 20 individuals with BDD and 43 mentally healthy controls (HC). We compared functional activity and whole-brain connectivity patterns of the amygdala and the fusiform gyrus (FFG) between both groups. Regression analyses were performed for associations of body dysmorphic symptoms with brain activity and connectivity. Individuals with BDD exhibited higher activity in the left amygdala compared to HC (p_FWE = .04) as well as increased functional connectivity of the left amygdala with a network including frontostriatal and temporal regions (p_FWE < .05). The FFG revealed increased functional connectivity in individuals with BDD, mapping to brain areas such as the cingulate cortex and temporo-limbic regions (p_FWE < .05). In HC, higher levels of body dysmorphic symptoms were associated with higher functional amygdala and FFG activity (p_FWE < .05). Individuals with BDD show aberrant functional activity and connectivity patterns within the amygdala and the FFG for negative emotional face processing. Body dysmorphic symptoms in HC are associated with a mild pattern of brain functional alterations, which could emphasize the relevance of a dimensional approach in addition to diagnosis. Treatments for BDD could benefit from targeting visual misperception and evaluation processes upon confrontation with emotional information.

Charting the human amygdala development across childhood and adolescence: Manual and automatic segmentation

The developmental pattern of the amygdala throughout childhood and adolescence has been inconsistently reported in previous neuroimaging studies. Given the relatively small size of the amygdala on full brain MRI scans, discrepancies may be partly due to methodological differences in amygdalar segmentation. To investigate the impact of volume extraction methods on amygdala volume, we compared FreeSurfer, FSL and volBrain segmentation measurements with those obtained by manual tracing. The manual tracing method, which we used as the 'gold standard', exhibited almost perfect intra- and inter-rater reliability. We observed systematic differences in amygdala volumes between automatic (FreeSurfer and volBrain) and manual methods. Specifically, compared with the manual tracing, FreeSurfer estimated larger amygdalae, and volBrain produced smaller amygdalae while FSL demonstrated a mixed pattern. The tracing bias was not uniform, but higher for smaller amygdalae. We further modeled amygdalar growth curves using accelerated longitudinal cohort data from the Chinese Color Nest Project (http://deepneuro.bnu.edu.cn/?p=163). Trajectory modeling and statistical assessments of the manually traced amygdalae revealed linearly increasing and parallel developmental patterns for both girls and boys, although the amygdalae of boys were larger than those of girls. Compared to these trajectories, the shapes of developmental curves were similar when using the volBrain derived volumes. FreeSurfer derived trajectories had more nonlinearities and appeared flatter. FSL derived trajectories demonstrated an inverted U shape and were significantly different from those derived from manual tracing method. The use of amygdala volumes adjusted for total gray-matter volumes, but not intracranial volumes, resolved the shape discrepancies and led to reproducible growth curves between manual tracing and the automatic methods (except FSL). Our findings revealed steady growth of the human amygdala, mirroring its functional development across the school age. Methodological improvements are warranted for current automatic tools to achieve more accurate amygdala structure at school age, calling for next generation tools.

Neural processing of emotional facial stimuli in specific phobia: An fMRI study

BACKGROUND

Patients with specific phobia (SP) show altered brain activation when confronted with phobia-specific stimuli. It is unclear whether this pathogenic activation pattern generalizes to other emotional stimuli. This study addresses this question by employing a well-powered sample while implementing an established paradigm using nonspecific aversive facial stimuli.

METHODS

N = 111 patients with SP, spider subtype, and N = 111 healthy controls (HCs) performed a supraliminal emotional face-matching paradigm contrasting aversive faces versus shapes in a 3-T magnetic resonance imaging scanner. We performed region of interest (ROI) analyses for the amygdala, the insula, and the anterior cingulate cortex using univariate as well as machine-learning-based multivariate statistics based on this data. Additionally, we investigated functional connectivity by means of psychophysiological interaction (PPI).

RESULTS

Although the presentation of emotional faces showed significant activation in all three ROIs across both groups, no group differences emerged in all ROIs. Across both groups and in the HC > SP contrast, PPI analyses showed significant task-related connectivity of brain areas typically linked to higher-order emotion processing with the amygdala. The machine learning approach based on whole-brain activity patterns could significantly differentiate the groups with 73% balanced accuracy.

CONCLUSIONS

Patients suffering from SP are characterized by differences in the connectivity of the amygdala and areas typically linked to emotional processing in response to aversive facial stimuli (inferior parietal cortex, fusiform gyrus, middle cingulate, postcentral cortex, and insula). This might implicate a subtle difference in the processing of nonspecific emotional stimuli and warrants more research furthering our understanding of neurofunctional alteration in patients with SP.

The Course of Disease in Major Depressive Disorder Is Associated With Altered Activity of the Limbic System During Negative Emotion Processing

BACKGROUND

Brain functional alterations during emotion processing in patients with major depressive disorder (MDD) compared with healthy control subjects (HCs) are frequently reported. However, evidence for functional correlates of emotion processing with regard to MDD trajectories is scarce. This study investigates the role of lifetime disease course for limbic brain activation during negative emotional face processing in patients with MDD.

METHODS

In a large sample of patients with MDD (n = 333; 58.55% female) and HCs (n = 333; 60.06% female), brain activation was investigated during a negative emotional face-processing task within a cross-sectional design. Differences between HC and MDD groups were analyzed. Previous disease course, characterized by 2 components, namely hospitalization and duration of illness, was regressed on brain activation of the amygdala, (para-)hippocampus, and insula in patients with MDD.

RESULTS

Patients with MDD showed increased activation in the amygdala, insula, and hippocampus compared with HCs (all p values corrected for familywise error [p_FWE] < .045). The hospitalization component showed negative associations with brain activation in the bilateral insula (right: p_FWE = .026, left: p_FWE = .019) and (para-)hippocampus (right: p_FWE = .038, left: p_FWE = .031). No significant association was found for the duration of illness component (all p_FWE > .057).

CONCLUSIONS

This study investigated negative emotion processing in a large sample of patients with MDD and HCs. Our results confirm limbic hyperactivation in patients with MDD during negative emotion processing; however, this hyperactivation may resolve with a more severe lifetime disease course in the insula and (para-)hippocampus-brain regions involved in emotion processing and regulation. These findings need further replication in longitudinal studies.

The endocannabinoid system in humans: significant associations between anandamide, brain function during reward feedback and a personality measure of reward dependence

Preclinical evidence indicates that the endocannabinoid system is involved in neural responses to reward. This study aimed to investigate associations between basal serum concentrations of the endocannabinoids anandamide (AEA) and 2-arachidonylglycerol (2-AG) with brain functional reward processing. Additionally, a personality measure of reward dependence was obtained. Brain functional data were obtained of 30 right-handed adults by conducting fMRI at 3 Tesla using a reward paradigm. Reward dependence was obtained using the subscale reward dependence of the Tridimensional Personality Questionnaire (TPQ). Basal concentrations of AEA and 2-AG were determined in serum. Analyzing the fMRI data, for AEA and 2-AG ANCOVAs were calculated using a full factorial model, with condition (reward > control, loss > control) and concentrations for AEA and 2-AG as factors. Regression analyses were conducted for AEA and 2-AG on TPQ-RD scores. A whole-brain analysis showed a significant interaction effect of AEA concentration by condition (positive vs. negative) within the putamen (x = 26, y = 16, z = -8, F13.51, TFCE_{(1, 54)} = 771.68, k = 70, P_FWE = 0.044) resulting from a positive association of basal AEA concentrations and putamen activity to rewarding stimuli, while this association was absent in the loss condition. AEA concentrations were significantly negatively correlated with TPQ reward dependence scores (r_spearman = -0.56, P = 0.001). These results show that circulating AEA may modulate brain activation during reward feedback and that the personality measure reward dependence is correlated with AEA concentrations in healthy human volunteers. Future research is needed to further characterize the nature of the lipids' influence on reward processing, the impact on reward anticipation and outcome, and on vulnerability for psychiatric disorders.

Neural basis underlying the trait of attachment anxiety and avoidance revealed by the amplitude of low-frequency fluctuations and resting-state functional connectivity

Background

Attachment theory demonstrates that early attachment experience shapes internal working models with mental representations of self and close relationships, which affects personality traits and interpersonal relationships in adulthood. Although research has focused on brain structural and functional underpinnings to disentangle attachment styles in healthy individuals, little is known about the spontaneous brain activity associated with self-reported attachment anxiety and avoidance during the resting state.

Methods

One hundred and nineteen individuals participated in the study, completing the Experience in Close Relationship scale immediately after an 8-min fMRI scanning. We used the resting-state functional magnetic resonance imaging (rs-fMRI) signal of the amplitude of low-frequency fluctuation and resting-state functional connectivity to identify attachment-related regions and networks.

Results

Consequently, attachment anxiety is closely associated with the amplitude of low-frequency fluctuations in the right posterior cingulate cortex, over-estimating emotional intensity and exaggerating outcomes. Moreover, the functional connectivity between the posterior cingulate cortex and fusiform gyrus increases detection ability for potential threat or separation information, facilitating behavior motivation. The attachment avoidance is positively correlated with the amplitude of low-frequency fluctuation in the bilateral lingual gyrus and right postcentral and negatively correlated with the bilateral orbital frontal cortex and inferior temporal gyrus. Functional connection with attachment avoidance contains critical nodes in the medial temporal lobe memory system, frontal-parietal network, social cognition, and default mode network necessary to deactivate the attachment system and inhibit attachment-related behavior.

Conclusion and implications

These findings clarify the amplitude of low-frequency fluctuation and resting-state functional connectivity neural signature of attachment style, associated with attachment strategies in attachment anxiety and attachment avoidance individuals. These findings may improve our understanding of the pathophysiology of the attachment-related disorder.

Anxious attachment is associated with heightened responsivity of a parietofrontal cortical network that monitors peri-personal space

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A parietofrontal cortical network is more active when stimuli are near the body.

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Responses of this network were positively correlated with “attachment anxiety”.

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No other types of attachment or symptoms accounted for this association.

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Connectivity strength within this network was not linked with attachment anxiety.

Background

Attachment, or affiliative bonding among conspecifics, is thought to involve neural mechanisms underlying behavioral responses to threat and reward-related social signals. However, attachment-oriented responses may also rely on basic sensorimotor processes. One sensorimotor system that may play a role in attachment is the parietofrontal cortical network that responds to stimuli that are near or approaching the body, the peripersonal space (PPS) monitoring system. We hypothesized that this network may vary in responsivity to such potentially harmful stimuli, particularly those with social salience, based on individual differences in attachment styles.

Methods

Young adults viewed images of human faces or cars that appeared to move towards or away from them, while functional magnetic resonance imaging data were collected. Correlations between each of four adult attachment styles, measured using the Relationship Questionnaire, and responses of the PPS network to approaching (versus withdrawing) stimuli were measured.

Results

A region-of-interest (ROI) analysis, focused on six cortical regions of the PPS network that showed significant responses to approaching versus withdrawing face stimuli in an independent sample (n = 80), revealed that anxious attachment style (but not the other 3 attachment styles) was significantly positively correlated with responses to faces (but not to cars) in all six ROIs (r = 0.33–0.49, p = 0.01–0.0001, n = 50).

Conclusions

These findings suggest that anxious attachment is associated with over-responsivity of a sensorimotor network involved in attending to social stimuli near the body.

Adult Attachment System Links With Brain Mu Opioid Receptor Availability In Vivo

BACKGROUND

Secure attachment is important in maintaining an individual's health and well-being. Attachment disturbances increase the risk for developing psychiatric disorders such as affective disorders. Yet, the neurobiological correlates of human attachment are poorly understood at the neurotransmitter level. We investigated whether adult attachment style is linked to functioning of the opioid and serotonergic systems in the human brain.

METHODS

We used positron emission tomography with radioligands [¹¹C]carfentanil and [¹¹C]MADAM to quantify mu opioid receptor (n = 39) and serotonin transporter (n = 37) availability in volunteers with no current psychiatric disorders. Attachment style was determined according to the Dynamic-Maturational Model of Attachment and Adaptation with the structured Adult Attachment Interview.

RESULTS

Secure attachment was associated with higher mu opioid receptor availability in the hippocampus, amygdala, thalamus, and prefrontal cortex when compared with insecure (i.e., avoidant or ambivalent groups combined) attachment. In contrast, attachment style was not associated with serotonin transporter availability.

CONCLUSIONS

Our results provide preliminary in vivo evidence that the opioid system may be involved in the neurocircuits associated with individual differences in adult attachment behavior. The results suggest that variation in mu opioid receptor availability may be linked with the individuals' social relationships and psychosocial well-being and thus contributes to risk for psychiatric morbidity.

Brain functional effects of electroconvulsive therapy during emotional processing in major depressive disorder

BACKGROUND

In treatment-resistant major depressive disorder (MDD), electroconvulsive therapy (ECT) is a treatment with high efficacy. While knowledge regarding changes in brain structure following ECT is growing, the effects of ECT on brain function during emotional processing are largely unknown.

OBJECTIVE

We investigated the effects of ECT on the activity of the anterior cingulate cortex (ACC) and amygdala during negative emotional stimuli processing and its association with clinical response.

METHODS

In this non-randomized longitudinal study, patients with MDD (n = 37) were assessed before and after treatment with ECT. Healthy controls (n = 37) were matched regarding age and gender. Functional magnetic resonance imaging (fMRI) was obtained twice, at baseline and after six weeks using a supraliminal face-matching paradigm. In order to evaluate effects of clinical response, additional post-hoc analyses were performed comparing responders to non-responders.

RESULTS

After ECT, patients with MDD showed a statistically significant increase in ACC activity during processing of negative emotional stimuli (p_FWE = .039). This effect was driven by responders (p_FWE = .023), while non-responders showed no increase. Responders also had lower pre-treatment ACC activity compared to non-responders (p_FWE = .025). No significant effects in the amygdala could be observed.

CONCLUSIONS

ECT leads to brain functional changes in the ACC, a relevant region for emotional regulation during processing of negative stimuli. Furthermore, baseline ACC activity might serve as a biomarker for treatment response. Findings are in accordance with recent studies highlighting properties of pre-treatment ACC to be associated with general antidepressive treatment response.

A neurobiological framework of separation anxiety and related phenotypes

In the DSM-5, separation anxiety disorder (SAD) is newly classified in the chapter on anxiety, renewing research efforts into its etiology. In this narrative review, we summarize the current literature on the genetic, endocrine, physiological, neural and neuropsychological underpinnings of SAD per se, SAD in the context of panic disorder, separation anxiety symptoms, and related intermediate phenotypes. SAD aggregates in families and has a heritability of ~43%. Variants in the oxytocin receptor, serotonin transporter, opioid receptor µ1, dopamine D4 receptor and translocator protein genes have all been associated with SAD. Dysregulation of the hypothalamus-pituitary-adrenal axis, dysfunctional cortico-limbic interaction and biased cognitive processing seem to constitute further neurobiological markers of separation anxiety. Hypersensitivity to carbon dioxide appears to be an endophenotype shared by SAD, panic disorder and anxiety sensitivity. The identification of biological risk markers and its multi-level integration hold great promise regarding the prediction of SAD risk, maintenance and course, and in the future may allow for the selection of indicated preventive and innovative, personalized therapeutic interventions.

Structural and functional neural correlates of vigilant and avoidant regulation style

BACKGROUND

Regulation of emotional arousal is a relevant factor for mental health. The investigation of neural underpinnings of regulation styles in healthy individuals may provide important insights regarding potential risk factors. To fill the gap of structural correlates of regulation styles and to expand previous results, we focused on the association between brain structure, neural responsiveness and vigilant/avoidant regulation style.

METHODS

In n = 302 healthy individuals regulation style was assessed with the Mainz Coping Inventory (MCI). Participants underwent structural and functional MRI during an emotion-processing paradigm. Structural MRI (voxel-based morphometry) and functional MRI were analysed in two regions of interest (amygdala and anterior cingulate cortex [ACC]).

RESULTS

Regulation styles did not show an association with brain structure after correction for gender, age, trait anxiety, depressive symptoms. During emotion processing, a vigilant regulation style was negatively associated with ACC activation.

LIMITATIONS

The cross-sectional study in a non-pathological sample is not adequate to unveil causalities or draw conclusions regarding prevention interventions.

CONCLUSION

Regulation styles are associated with specific neural activation patterns. The association of a high-vigilant regulation style and low ACC activation during emotion processing in healthy participants might be a potential risk factor.

The role of BDNF methylation and Val66 Met in amygdala reactivity during emotion processing

Epigenetic alterations of the brain-derived neurotrophic factor (BDNF) gene have been associated with psychiatric disorders in humans and with differences in amygdala BDNF mRNA levels in rodents. This human study aimed to investigate the relationship between the functional BDNF-Val⁶⁶ Met polymorphism, its surrounding DNA methylation in BDNF exon IX, amygdala reactivity to emotional faces, and personality traits. Healthy controls (HC, n = 189) underwent functional MRI during an emotional face-matching task. Harm avoidance, novelty seeking and reward dependence were measured using the Tridimensional Personality Questionnaire (TPQ). Individual BDNF methylation profiles were ascertained and associated with several BDNF single nucleotide polymorphisms surrounding the BDNF-Val⁶⁶ Met, amygdala reactivity, novelty seeking and harm avoidance. Higher BDNF methylation was associated with higher amygdala reactivity (x = 34, y = 0, z = -26, t₍₁₆₆₎ = 3.00, TFCE = 42.39, p_(FWE) = .045), whereby the BDNF-Val⁶⁶ Met genotype per se did not show any significant association with brain function. Furthermore, novelty seeking was negatively associated with BDNF methylation (r = -.19, p = .015) and amygdala reactivity (r = -.17, p = .028), while harm avoidance showed a trend for a positive association with BDNF methylation (r = .14, p = .066). The study provides first insights into the relationship among BDNF methylation, BDNF genotype, amygdala reactivity and personality traits in humans, highlighting the multidimensional relations among genetics, epigenetics, and neuronal functions. The present study suggests a possible involvement of epigenetic BDNF modifications in psychiatric disorders and related brain functions, whereby high BDNF methylation might reduce BDNF mRNA expression and upregulate amygdala reactivity.

On a continuum to anxiety disorders: Adolescents at parental risk for anxiety show smaller rostral anterior cingulate cortex and insula thickness

BACKGROUND

Having a parent with an anxiety disorder increases the risk of anxiety symptoms and anxiety disorders during the lifespan. Moreover, childhood and adolescence anxiety disorders and symptoms have been linked to a range of brain structure abnormalities. However, to date, no study has investigated brain anatomy in adolescents at high risk based on parental anxiety disorders and in adolescents with an anxiety disorder but without any treatment or therapy.

METHODS

Anatomical images from magnetic resonance imaging of 68 adolescents with anxiety disorders without any treatment (N = 20), at risk for anxiety because of their parents' anxiety disorders (N = 21), and comparison youths (N = 27), were analyzed using Freesurfer.

RESULTS

Compared to comparison group, smaller cortical thickness of the rostral anterior cingulate cortex and of the insula was observed in anxious and at-risk groups; smaller amygdala volume was observed in the anxious group only.

LIMITATIONS

The age range studied is large (10 to 17 years old). Moreover, this study is cross-sectional. Since adolescence is one of the biggest periods of cerebral reorganization, longitudinal follow-up of these youths would be necessary.

CONCLUSIONS

Smaller rostral anterior cingulate cortex and insula cortical thickness appear to be cerebral markers of the risk of developing an anxiety disorder in adolescence. The reduction of the amygdala volume seems to be linked to the onset of the disorder.

[Separation anxiety disorder in adults - a new diagnostic category]

Anxiety separation disorder (SAD) became the subject of increased attention of researchers in recent decades. DSM-5 and project of ICD-11 allow us to treat this disorder as an independent nosological unit without attachment to age. The review provides information on the prevalence, clinical manifestations and diagnosis of SAD in adults, summarizes information on the etiopathogenesis, relations to other psychiatric disorders, and highlights the lack of modern therapeutic approaches to SAD. The purpose of this review is to raise the level of knowledge about SAD and its new positioning in classification systems.

Effects of cumulative illness severity on hippocampal gray matter volume in major depression: a voxel-based morphometry study

BACKGROUND

Patients with major depression show reduced hippocampal volume compared to healthy controls. However, the contribution of patients' cumulative illness severity to hippocampal volume has rarely been investigated. It was the aim of our study to find a composite score of cumulative illness severity that is associated with hippocampal volume in depression.

METHODS

We estimated hippocampal gray matter volume using 3-tesla brain magnetic resonance imaging in 213 inpatients with acute major depression according to DSM-IV criteria (employing the SCID interview) and 213 healthy controls. Patients' cumulative illness severity was ascertained by six clinical variables via structured clinical interviews. A principal component analysis was conducted to identify components reflecting cumulative illness severity. Regression analyses and a voxel-based morphometry approach were used to investigate the influence of patients' individual component scores on hippocampal volume.

RESULTS

Principal component analysis yielded two main components of cumulative illness severity: Hospitalization and Duration of Illness. While the component Hospitalization incorporated information from the intensity of inpatient treatment, the component Duration of Illness was based on the duration and frequency of illness episodes. We could demonstrate a significant inverse association of patients' Hospitalization component scores with bilateral hippocampal gray matter volume. This relationship was not found for Duration of Illness component scores.

CONCLUSIONS

Variables associated with patients' history of psychiatric hospitalization seem to be accurate predictors of hippocampal volume in major depression and reliable estimators of patients' cumulative illness severity. Future studies should pay attention to these measures when investigating hippocampal volume changes in major depression.

Brain activity underlying negative self- and other-perception in adolescents: The role of attachment-derived self-representations

One of teenagers’ key developmental tasks is to engage in new and meaningful relationships with peers and adults outside the family context. Attachment-derived expectations about the self and others in terms of internal attachment working models have the potential to shape such social reorientation processes critically and thereby influence adolescents’ social-emotional development and social integration. Because the neural underpinnings of this developmental task remain largely unknown, we sought to investigate them by functional magnetic resonance imaging. We asked n = 44 adolescents (ages 12.01–18.84 years) to evaluate positive and negative adjectives regarding either themselves or a close other during an adapted version of the well-established self-other trait-evaluation task. As measures of attachment, we obtained scores reflecting participants’ positive versus negative attachment-derived self- and other-models by means of the Relationship Questionnaire. We controlled for possible confounding factors by also obtaining scores reflecting internalizing/externalizing problems, schizotypy, and borderline symptomatology. Our results revealed that participants with a more negative attachment-derived self-model showed increased brain activity during positive and negative adjective evaluation regarding the self, but decreased brain activity during negative adjective evaluation regarding a close other, in bilateral amygdala/parahippocampus, bilateral anterior temporal pole/anterior superior temporal gyrus, and left dorsolateral prefrontal cortex. These findings suggest that a low positivity of the self-concept characteristic for the attachment anxiety dimension may influence neural information processing, but in opposite directions when it comes to self- versus (close) other-representations. We discuss our results in the framework of attachment theory and regarding their implications especially for adolescent social-emotional development and social integration.

The Limbic System in Youth Depression: Brain Structural and Functional Alterations in Adolescent In-patients with Severe Depression

Adolescent-onset major depressive disorder (MDD) is associated with an increased risk of recurrent depressive episodes, suicidal behaviors, and psychiatric morbidity throughout the lifespan. The objective of the present study was to investigate brain structural and functional changes in adolescent patients with MDD. Furthermore, we aimed to clarify the influence of early-life stress on brain function and structure. The study investigated adolescent patients with severe MDD (n=20, mean age=16.0, range=15-18 years) and a control sample of matched healthy adolescents (n=21, mean age=16.6, range=15-18 years). Functional MRI data were obtained using a face-matching paradigm to investigate emotion processing. Structural MRI data were analyzed using voxel-based morphometry (VBM). In line with previous studies on adult MDD, adolescent patients showed elevated amygdala activity to negative and reduced amygdala activity to positive emotional stimuli. Furthermore, MDD patients showed smaller hippocampal volumes compared to healthy adolescents. Higher levels of childhood maltreatment were associated with smaller hippocampal volumes in both depressed patients and healthy controls, whereby no associations between amygdala reactivity and childhood maltreatment were found. Our results suggest that hippocampal alterations in youth MDD patients may at least partly be traced back to higher occurrence of early-life adverse experiences. Regarding the strong morphometric impact of childhood maltreatment and its distinctly elevated prevalence in MDD populations, this study provides an alternative explanation for frequently observed limbic structural abnormalities in depressed patients.

Subclinical Agoraphobia Symptoms and Regional Brain Volumes in Non-clinical Subjects: Between Compensation and Resilience?

Background: Symptoms of anxiety are present not only in panic disorder or other anxiety disorders, but are highly prevalent in the general population. Despite increasing biological research on anxiety disorders, there is little research on understanding subclinical or sub-threshold symptoms relating to anxiety in non-clinical community samples, which could give clues to factors relating to resilience or compensatory changes. Aims:This study focused on brain structural correlates of subclinical anxiety/agoraphobia symptoms from a multi-center imaging study. Methods: We obtained high-resolution structural T1 MRI scans of 409 healthy young participants and used the CAT12 toolbox for voxel-based morphometry (VBM) analysis. Subjects provided self-ratings of anxiety using the SCL-90-R, from which we used the phobia subscale, covering anxiety symptoms related to those of panic and agoraphobia spectrum. Results: We found significant (p < 0.05, FDR-corrected) correlations (mostly positive) of cortical volume with symptom severity, including the right lingual gyrus and calcarine sulcus, as well as left calcarine sulcus, superior, middle, and inferior temporal gyri. Uncorrected exploratory analysis also revealed positive correlations with GMV in orbitofrontal cortex, precuneus, and insula. Conclusions: Our findings show brain structural associations of subclinical symptoms of anxiety, which overlap with those seen in panic disorder or agoraphobia. This is consistent with a dimensional model of anxiety, which is reflected not only functionally but also on the structural level.

Effects of electroconvulsive therapy on amygdala function in major depression - a longitudinal functional magnetic resonance imaging study

BACKGROUND

Electroconvulsive therapy (ECT) is one of the most effective treatments for severe depression. However, little is known regarding brain functional processes mediating ECT effects.

METHOD

In a non-randomized prospective study, functional magnetic resonance imaging data during the automatic processing of subliminally presented emotional faces were obtained twice, about 6 weeks apart, in patients with major depressive disorder (MDD) before and after treatment with ECT (ECT, n = 24). Additionally, a control sample of MDD patients treated solely with pharmacotherapy (MED, n = 23) and a healthy control sample (HC, n = 22) were obtained.

RESULTS

Before therapy, both patient groups equally showed elevated amygdala reactivity to sad faces compared with HC. After treatment, a decrease in amygdala activity to negative stimuli was discerned in both patient samples indicating a normalization of amygdala function, suggesting mechanisms potentially unspecific for ECT. Moreover, a decrease in amygdala activity to sad faces was associated with symptomatic improvements in the ECT sample (r spearman = -0.48, p = 0.044), and by tendency also for the MED sample (r spearman = -0.38, p = 0.098). However, we did not find any significant association between pre-treatment amygdala function to emotional stimuli and individual symptom improvement, neither for the ECT sample, nor for the MED sample.

CONCLUSIONS

In sum, the present study provides first results regarding functional changes in emotion processing due to ECT treatment using a longitudinal design, thus validating and extending our knowledge gained from previous treatment studies. A limitation was that ECT patients received concurrent medication treatment.

Prefrontal brain responsiveness to negative stimuli distinguishes familial risk for major depression from acute disorder

BACKGROUND

Identifying reliable trait markers of familial risk for major depressive disorder (MDD) is a challenge in translational psychiatric research. In individuals with acute MDD, dysfunctional connectivity patterns of prefrontal areas have been shown repeatedly. However, it has been unclear in which neuronal networks functional alterations in individuals at familial risk for MDD might be present and to what extent they resemble findings previously reported in those with acute MDD.

METHODS

We investigated differences in blood oxygen level-dependent (BOLD) response of the medial orbitofrontal cortex (OFC) and dorsolateral prefrontal cortex (DLPFC) to aversive stimuli between acute MDD and familial risk for the disorder in healthy first-degree relatives of acutely depressed patients with MDD (HC-FH+), healthy age- and sex-matched controls without any family history of depression (HC-FH-), and acutely depressed patients with MDD with (MDD-FH+) and without a family history of depression (MDD-FH-) during a frequently used emotional face-matching paradigm. Analyses of task-specific network connectivity were conducted in terms of psychophysiological interactions (PPI).

RESULTS

The present analysis included a total of 100 participants: 25 HC-FH+, 25 HC-FH-, 25 MDD-FH+ and 25 MDD-FH-. Patients with MDD exhibited significantly increased activation in the medial OFC to negative stimuli irrespective of familial risk status, whereas healthy participants at familial risk and patients with MDD alike showed significant hypoactivation in the DLPFC compared with healthy participants without familial risk. The PPI analyses revealed significantly enhanced task-specific coupling between the medial OFC and differing cortical areas in individuals with acute MDD and those with familial risk for the disorder.

LIMITATIONS

The main limitation of our study is its cross-sectional design.

CONCLUSION

Whereas hypoactivation during negative emotion processing in the DLPFC appears as a common feature in both healthy high-risk individuals and acutely depressed patients, activation patterns of the medial OFC and its underlying connectivity seem to distinguish familial risk from acute disorder.

Prefrontal gray matter volume mediates genetic risks for obesity

Genetic and neuroimaging research has identified neurobiological correlates of obesity. However, evidence for an integrated model of genetic risk and brain structural alterations in the pathophysiology of obesity is still absent. Here we investigated the relationship between polygenic risk for obesity, gray matter structure and body mass index (BMI) by the use of univariate and multivariate analyses in two large, independent cohorts (n=330 and n=347). Higher BMI and higher polygenic risk for obesity were significantly associated with medial prefrontal gray matter decrease, and prefrontal gray matter was further shown to significantly mediate the effect of polygenic risk for obesity on BMI in both samples. Building on this, the successful individualized prediction of BMI by means of multivariate pattern classification algorithms trained on whole-brain imaging data and external validations in the second cohort points to potential clinical applications of this imaging trait marker.

Priming the Secure Attachment Schema Affects the Emotional Face Processing Bias in Attachment Anxiety: An fMRI Research

Our study explored how priming with a secure base schema affects the processing of emotional facial stimuli in individuals with attachment anxiety. We enrolled 42 undergraduate students between 18 and 27 years of age, and divided them into two groups: attachment anxiety and attachment secure. All participants were primed under two conditions, the secure priming using references to the partner, and neutral priming using neutral references. We performed repeated attachment security priming combined with a dual-task paradigm and functional magnetic resonance imaging. Participants’ reaction times in terms of responding to the facial stimuli were also measured. Attachment security priming can facilitate an individual’s processing of positive emotional faces; for instance, the presentation of the partner’s name was associated with stronger activities in a wide range of brain regions and faster reaction times for positive facial expressions in the subjects. The current finding of higher activity in the left-hemisphere regions for secure priming rather than neutral priming is consistent with the prediction that attachment security priming triggers the spread of the activation of a positive emotional state. However, the difference in brain activity during processing of both, positive and negative emotional facial stimuli between the two priming conditions appeared in the attachment anxiety group alone. This study indicates that the effect of attachment secure priming on the processing of emotional facial stimuli could be mediated by chronic attachment anxiety. In addition, it highlights the association between higher-order processes of the attachment system (secure attachment schema priming) and early-stage information processing system (attention), given the increased attention toward the effects of secure base schema on the processing of emotion- and attachment-related information among the insecure population. Thus, the following study has applications in providing directions for clinical treatment of mood disorders in attachment anxiety.

Annual Research Review: Childhood maltreatment, latent vulnerability and the shift to preventative psychiatry - the contribution of functional brain imaging

BACKGROUND

Childhood maltreatment is a potent predictor of poor mental health across the life span. We argue that there is a need to improve the understanding of the mechanisms that confer psychiatric vulnerability following maltreatment, if we are to progress from simply treating those with a manifest disorder, to developing effective preventative approaches that can help offset the likelihood that such disorders will emerge in the first place.

METHODS

We review extant functional neuroimaging studies of children and adolescents exposed to early neglect and/or maltreatment, including physical, sexual and emotional abuse across four neurocognitive domains: threat processing, reward processing, emotion regulation and executive control. Findings are discussed in the context of 'latent vulnerability', where alterations in neurocognitive function are considered to carry adaptive value in early adverse caregiving environments but confer long-term risk.

RESULTS

Studies on threat processing indicate heightened as well as depressed neural responsiveness in maltreated samples, particularly in the amygdala, thought to reflect threat hypervigilance and avoidance respectively. Studies on reward processing generally report blunted neural response to anticipation and receipt of rewards, particularly in the striatum, patterns associated with depressive symptomatology. Studies on emotion regulation report increased activation of the anterior cingulate cortex (ACC) during active emotion regulation, possibly reflecting greater effortful processing. Finally, studies of executive control report increased dorsal ACC activity during error monitoring and inhibition.

CONCLUSIONS

An emerging body of work indicates that altered neurocognitive functioning following maltreatment: (a) is evident even in the absence of overt psychopathology; (b) is consistent with perturbations seen in individuals presenting with psychiatric disorder; (c) can predict future psychiatric symptomatology. These findings suggest that maltreatment leads to neurocognitive alterations that embed latent vulnerability to psychiatric disorder, establishing a compelling case for identifying those children at most risk and developing mechanistically informed models of preventative intervention. Such interventions should aim to offset the likelihood of any future psychiatric disorder.

Attachment Avoidance Is Significantly Related to Attentional Preference for Infant Faces: Evidence from Eye Movement Data

Objective: To determine the influence of adult attachment orientations on infant preference. Methods: We adopted eye-tracking technology to monitor childless college women's eye movements when looking at pairs of faces, including one adult face (man or woman) and one infant face, with three different expressions (happy, sadness, and neutral). The participants (N = 150; 84% Han ethnicity) were aged 18-29 years (M = 19.22, SD = 1.72). A random intercepts multilevel linear regression analysis was used to assess the unique contribution of attachment avoidance, determined using the Experiences in Close Relationships scale, to preference for infant faces. Results: Women with higher attachment avoidance showed less infant preference, as shown by less sustained overt attentional bias to the infant face than the adult face based on fixation time and count. Conclusion: Adult attachment might be related to infant preference according to eye movement indices. Women with higher attachment avoidance may lack attentional preference for infant faces. The findings may aid the treatment and remediation of the interactions between children and mothers with insecure attachment.

TNF receptors 1 and 2 exert distinct region-specific effects on striatal and hippocampal grey matter volumes (VBM) in healthy adults

Tumour necrosis factor alpha (TNFα) has been implicated in the pathophysiology of neurodegenerative and neuropsychiatric disease, with research highlighting a role for TNFα in hippocampal and striatal regulation. TNFα signals are primarily transduced by TNF receptors 1 and 2 (TNFR1 and TNFR2), encoded by TNFRSF1A and TNFRSF1B, which exert opposing effects on cell survival (TNFR1, neurodegenerative; TNFR2, neuroprotective). We therefore sought to explore the respective roles of TNFR1 and TNFR2 in the regulation of hippocampal and striatal morphology in an imaging genetics study. Voxel-based morphometry was used to analyse the associations between TNFRSF1A (rs4149576 and rs4149577) and TNFRSF1B (rs1061624) genotypes and grey matter structure. The final samples comprised a total of 505 subjects (mean age = 33.29, SD = 11.55 years; 285 females and 220 males) for morphometric analyses of rs1061624 and rs4149576, and 493 subjects for rs4149577 (mean age = 33.20, SD = 11.56 years; 281 females and 212 males). Analyses of TNFRSF1A single nucleotide polymorphisms (SNPs) rs4149576 and rs4149577 showed highly significant genotypic associations with striatal volume but not the hippocampus. Specifically, for rs4149576, G homozygotes were associated with reduced caudate nucleus volumes relative to A homozygotes and heterozygotes, whereas for rs4149577, reduced caudate volumes were observed in C homozygotes relative to T homozygotes and heterozygotes. Analysis of the TNFRSF1B SNP rs1061624 yielded a significant association with hippocampal but not with striatal volume, whereby G homozygotes were associated with increased volumes relative to A homozygotes and heterozygotes. Our findings indicate a role for TNFR1 in regulating striatal but not hippocampal morphology, as well as a complementary role for TNFR2 in hippocampal but not in striatal morphology.

Discrimination of amygdala response predicts future separation anxiety in youth with early deprivation

BACKGROUND

Significant disruption in caregiving is associated with increased internalizing symptoms, most notably heightened separation anxiety symptoms during childhood. It is also associated with altered functional development of the amygdala, a neurobiological correlate of anxious behavior. However, much less is known about how functional alterations of amygdala predict individual differences in anxiety. Here, we probed amygdala function following institutional caregiving using very subtle social-affective stimuli (trustworthy and untrustworthy faces), which typically result in large differences in amygdala signal, and change in separation anxiety behaviors over a 2-year period. We hypothesized that the degree of differentiation of amygdala signal to trustworthy versus untrustworthy face stimuli would predict separation anxiety symptoms.

METHODS

Seventy-four youths mean (SD) age = 9.7 years (2.64) with and without previous institutional care, who were all living in families at the time of testing, participated in an fMRI task designed to examine differential amygdala response to trustworthy versus untrustworthy faces. Parents reported on their children's separation anxiety symptoms at the time of scan and again 2 years later.

RESULTS

Previous institutional care was associated with diminished amygdala signal differences and behavioral differences to the contrast of untrustworthy and trustworthy faces. Diminished differentiation of these stimuli types predicted more severe separation anxiety symptoms 2 years later. Older age at adoption was associated with diminished differentiation of amygdala responses.

CONCLUSIONS

A history of institutional care is associated with reduced differential amygdala responses to social-affective cues of trustworthiness that are typically exhibited by comparison samples. Individual differences in the degree of amygdala differential responding to these cues predict the severity of separation anxiety symptoms over a 2-year period. These findings provide a biological mechanism to explain the associations between early caregiving adversity and individual differences in internalizing symptomology during development, thereby contributing to individualized predictions of future clinical outcomes.

Adolescent neurobiological susceptibility to social context

Adolescence has been characterized as a period of heightened sensitivity to social contexts. However, adolescents vary in how their social contexts affect them. According to neurobiological susceptibility models, endogenous, biological factors confer some individuals, relative to others, with greater susceptibility to environmental influences, whereby more susceptible individuals fare the best or worst of all individuals, depending on the environment encountered (e.g., high vs. low parental warmth). Until recently, research guided by these theoretical frameworks has not incorporated direct measures of brain structure or function to index this sensitivity. Drawing on prevailing models of adolescent neurodevelopment and a growing number of neuroimaging studies on the interrelations among social contexts, the brain, and developmental outcomes, we review research that supports the idea of adolescent neurobiological susceptibility to social context for understanding why and how adolescents differ in development and well-being. We propose that adolescent development is shaped by brain-based individual differences in sensitivity to social contexts - be they positive or negative - such as those created through relationships with parents/caregivers and peers. Ultimately, we recommend that future research measure brain function and structure to operationalize susceptibility factors that moderate the influence of social contexts on developmental outcomes.

Annual Research Review: Enduring neurobiological effects of childhood abuse and neglect

BACKGROUND

Childhood maltreatment is the most important preventable cause of psychopathology accounting for about 45% of the population attributable risk for childhood onset psychiatric disorders. A key breakthrough has been the discovery that maltreatment alters trajectories of brain development.

METHODS

This review aims to synthesize neuroimaging findings in children who experienced caregiver neglect as well as from studies in children, adolescents and adults who experienced physical, sexual and emotional abuse. In doing so, we provide preliminary answers to questions regarding the importance of type and timing of exposure, gender differences, reversibility and the relationship between brain changes and psychopathology. We also discuss whether these changes represent adaptive modifications or stress-induced damage.

RESULTS

Parental verbal abuse, witnessing domestic violence and sexual abuse appear to specifically target brain regions (auditory, visual and somatosensory cortex) and pathways that process and convey the aversive experience. Maltreatment is associated with reliable morphological alterations in anterior cingulate, dorsal lateral prefrontal and orbitofrontal cortex, corpus callosum and adult hippocampus, and with enhanced amygdala response to emotional faces and diminished striatal response to anticipated rewards. Evidence is emerging that these regions and interconnecting pathways have sensitive exposure periods when they are most vulnerable.

CONCLUSIONS

Early deprivation and later abuse may have opposite effects on amygdala volume. Structural and functional abnormalities initially attributed to psychiatric illness may be a more direct consequence of abuse. Childhood maltreatment exerts a prepotent influence on brain development and has been an unrecognized confound in almost all psychiatric neuroimaging studies. These brain changes may be best understood as adaptive responses to facilitate survival and reproduction in the face of adversity. Their relationship to psychopathology is complex as they are discernible in both susceptible and resilient individuals with maltreatment histories. Mechanisms fostering resilience will need to be a primary focus of future studies.

Neurodevelopmental correlates of proneness to guilt and shame in adolescence and early adulthood

Investigating how brain development during adolescence and early adulthood underlies guilt- and shame-proneness may be important for understanding risk processes for mental disorders. The aim of this study was to investigate the neurodevelopmental correlates of interpersonal guilt- and shame-proneness in healthy adolescents and young adults using structural magnetic resonance imaging (sMRI). Sixty participants (age range: 15–25) completed sMRI and self-report measures of interpersonal guilt- and shame-proneness. Independent of interpersonal guilt, higher levels of shame-proneness were associated with thinner posterior cingulate cortex (PCC) thickness and smaller amygdala volume. Higher levels of shame-proneness were also associated with attenuated age-related reductions in thickness of lateral orbitofrontal cortex (lOFC). Our findings highlight the complexities in understanding brain–behavior relationships during the adolescent/young adult period. Results were consistent with growing evidence that accelerated cortical thinning during adolescence may be associated with superior socioemotional functioning. Further research is required to understand the implications of these findings for mental disorders characterized by higher levels of guilt and shame.

Neuroplasticity in response to cognitive behavior therapy for social anxiety disorder

Patients with anxiety disorders exhibit excessive neural reactivity in the amygdala, which can be normalized by effective treatment like cognitive behavior therapy (CBT). Mechanisms underlying the brain's adaptation to anxiolytic treatments are likely related both to structural plasticity and functional response alterations, but multimodal neuroimaging studies addressing structure-function interactions are currently missing. Here, we examined treatment-related changes in brain structure (gray matter (GM) volume) and function (blood-oxygen level dependent, BOLD response to self-referential criticism) in 26 participants with social anxiety disorder randomly assigned either to CBT or an attention bias modification control treatment. Also, 26 matched healthy controls were included. Significant time × treatment interactions were found in the amygdala with decreases both in GM volume (family-wise error (FWE) corrected P(FWE) = 0.02) and BOLD responsivity (P(FWE) = 0.01) after successful CBT. Before treatment, amygdala GM volume correlated positively with anticipatory speech anxiety (P(FWE)=0.04), and CBT-induced reduction of amygdala GM volume (pre-post) correlated positively with reduced anticipatory anxiety after treatment (P(FWE) ⩽ 0.05). In addition, we observed greater amygdala neural responsivity to self-referential criticism in socially anxious participants, as compared with controls (P(FWE) = 0.029), before but not after CBT. Further analysis indicated that diminished amygdala GM volume mediated the relationship between decreased neural responsivity and reduced social anxiety after treatment (P=0.007). Thus, our results suggest that improvement-related structural plasticity impacts neural responsiveness within the amygdala, which could be essential for achieving anxiety reduction with CBT.

Differing brain structural correlates of familial and environmental risk for major depressive disorder revealed by a combined VBM/pattern recognition approach

BACKGROUND

Neuroimaging traits of either familial or environmental risk for major depressive disorder (MDD) have been interpreted as possibly useful vulnerability markers. However, the simultaneous occurrence of familial and environmental risk might prove to be a major obstacle in the attempt of recent studies to confine the precise impact of each of these conditions on brain structure. Moreover, the exclusive use of group-level analyses does not permit prediction of individual illness risk which would be the basic requirement for the clinical application of imaging vulnerability markers. Hence, we aimed to distinguish between brain structural characteristics of familial predisposition and environmental stress by using both group- and individual-level analyses.

METHOD

We investigated grey matter alterations between 20 healthy control subjects (HC) and 20 MDD patients; 16 healthy first-degree relatives of MDD patients (FH+) and 20 healthy subjects exposed to former childhood maltreatment (CM+) by using a combined VBM/pattern recognition approach.

RESULTS

We found similar grey matter reductions in the insula and the orbitofrontal cortex in patients and FH+ subjects and in the hippocampus in patients and CM+ subjects. No direct overlap in grey matter alterations was found between FH+ and CM+ subjects. Pattern classification successfully detected subjects at risk for the disease even by strictly focusing on morphological traits of MDD.

CONCLUSIONS

Familial and environmental risk factors for MDD are associated with differing morphometric anomalies. Pattern recognition might be a promising instrument in the search for and future application of vulnerability markers for MDD.

Evidence of an IFN-γ by early life stress interaction in the regulation of amygdala reactivity to emotional stimuli

INTRODUCTION

Since numerous studies have found that exposure to early life stress leads to increased peripheral inflammation and psychiatric disease, it is thought that peripheral immune activation precedes and possibly mediates the onset of stress-associated psychiatric disease. Despite early studies, IFNγ has received little attention relative to other inflammatory cytokines in the context of the pathophysiology of affective disorders. Neuroimaging endophenotypes have emerged recently as a promising means of elucidating these types of complex relationships including the modeling of the interaction between environmental factors and genetic predisposition. Here we investigate the GxE relationship between early-life stress and genetic variants of IFNγ on emotion processing.

METHODS

To investigate the impact of the relationship between genetic variants of IFNγ (rs1861494, rs2069718, rs2430561) and early life stress on emotion processing, a sample of healthy adults (n=409) undergoing an emotional faces paradigm in an fMRI study were genotyped and analysed. Information on early life stress was obtained via Childhood Trauma Questionnaire (CTQ).

RESULTS

A positive association between early life stress and amygdala reactivity was found. Specifically, the main effect of genotype of rs1861494 on amygdala reactivity indicates a higher neural response in C allele carriers compared to T homozygotes, while we did not find main effects of rs2069718 and rs2430561. Importantly, interaction analyses revealed a specific interaction between IFNγ genotype (rs1861494) and early life stress affecting amygdala reactivity to emotional faces, resulting from a positive association between CTQ scores and amygdala reactivity in C allele carriers while this association was absent in T homozygotes.

CONCLUSIONS

Our findings indicate that firstly the genetic variant of IFNγ (rs1861494) is involved with the regulation of amygdala reactivity to emotional stimuli and secondly, that this genetic variant moderates effects of early life stress on emotion processing. These findings reiterate the importance that inflammatory genes play in the interaction with early life stress and the regulation of emotion processing.

Reward Processing in Unipolar and Bipolar Depression: A Functional MRI Study

Differentiating bipolar disorders (BD) from unipolar depression (UD) remains a major clinical challenge. The identification of neurobiological markers may help to differentiate these disorders, particularly during depressive episodes. This cross-sectional study, including 33 patients with UD, 33 patients with BD, and 34 healthy controls, is one of the first to directly compare UD and BD with respect to reward processing. A card-guessing paradigm was employed and brain activity associated with reward processing was investigated by means of fMRI. A 3 (group) × 2 (condition: reward>control, loss>control) ANOVA was conducted using the nucleus accumbens (NAcc) as ROI. Furthermore, a whole-brain approach was applied. A functional connectivity analysis was performed to characterize diagnosis-related alterations in the functional coupling between the NAcc and other brain areas. The ANOVA revealed higher activity for healthy controls (HCs) than for BD and UD in the NAcc during reward processing. Moreover, UD showed a higher functional connectivity between the NAcc and the VTA than HC. The patients groups could be differentiated in that BD showed a decreased activation, in the reward condition, of the NAcc, caudate nucleus, thalamus, putamen, insula, and prefrontal areas compared with UD. These results may help to refine the understanding of neural correlates of reward processing in both disorders, and to understand the neural underpinnings of anhedonia, a core symptom of depressive episodes.

Enhanced neural responsiveness to reward associated with obesity in the absence of food-related stimuli

BACKGROUND

Obesity has been characterized by alterations in brain structure and function associated with emotion processing and regulation. Particularly, aberrations in food-related reward processing have been frequently demonstrated in obese subjects. However, it remains unclear whether reward-associated functional aberrations in obesity are specific for food-related stimuli or represent a general deficit in reward processing, extending to other stimulus domains. Given the crucial role of rewarding effects in the development of obesity and the ongoing discussion on overlapping neurobiological traits of obesity and psychiatric disorders such as depression and substance-related disorders, this study aimed to investigate the possibility of altered reward processing in obese subjects to occur in the absence of food-related stimuli during a monetary reward condition.

METHODS

Twenty-nine healthy obese subjects (body mass index >30) and 29 healthy, age-, and sex-matched control subjects of normal weight underwent functional MRI during a frequently used card guessing paradigm. A Group × Condition (win vs. loss) ANOVA was conducted to investigate differences between obese and normal-weight subjects.

RESULTS

We found significant Group × Condition interaction effects in brain areas involved in emotion regulation and reward processing including the insula, the striatum, and the orbitofrontal cortex (OFC). This interaction was predominantly driven by a significant increase in blood oxygenation level dependent (BOLD) response in obese individuals while experiencing reward.

CONCLUSIONS

Enhanced neural activation in obesity during reward processing seems to be apparent even in the absence of food-related stimuli and, thus, might point to generalized dysfunctions in reward-related brain circuits in obese individuals.