Functional magnetic resonance imaging correlates of emotion recognition and voluntary attentional regulation in depression: A generalized psycho-physiological interaction study

Abnormal activation patterns in MT+ during visual motion perception in major depressive disorder

Objective

Previous studies have found that patients with Major Depressive Disorder (MDD) exhibit impaired visual motion perception capabilities, and multi-level abnormalities in the human middle temporal complex (MT+), a key brain area for processing visual motion information. However, the brain activity pattern of MDD patients during the perception of visual motion information is currently unclear. In order to study the effect of depression on the activity and functional connectivity (FC) of MT+ during the perception of visual motion information, we conducted a study combining task-state fMRI and psychophysical paradigm to compare MDD patients and healthy control (HC).

Methods

Duration threshold was examined through a visual motion perception psychophysical experiment. In addition, a classic block-design grating motion task was utilized for fMRI scanning of 24 MDD patients and 25 HC. The grating moved randomly in one of eight directions. We examined the neural activation under visual stimulation conditions compared to the baseline and FC.

Results

Compared to HC group, MDD patients exhibited increased duration threshold. During the task, MDD patients showed decreased beta value and percent signal change in left and right MT+. In the sample comprising MDD and HC, there was a significant negative correlation between beta value in right MT+ and duration threshold. And in MDD group, activation in MT+ were significantly correlated with retardation score. Notably, no such differences in activation were observed in primary visual cortex (V1). Furthermore, when left MT+ served as the seed region, compared to the HC, MDD group showed increased FC with right calcarine fissure and surrounding cortex and decreased FC with left precuneus.

Conclusion

Overall, the findings of this study highlight that the visual motion perception function impairment in MDD patients relates to abnormal activation patterns in MT+, and task-related activity are significantly connected to the retardation symptoms of the disease. This not only provides insights into the potential neurobiological mechanisms behind visual motion perception disorder in MDD patients from the aspect of task-related brain activity, but also supports the importance of MT+ as a candidate biomarker region for MDD.

Effect of non-invasive spinal cord stimulation in unmedicated adults with major depressive disorder: a pilot randomized controlled trial and induced current flow pattern

Converging theoretical frameworks suggest a role and a therapeutic potential for spinal interoceptive pathways in major depressive disorder (MDD). Here, we aimed to evaluate the antidepressant effects and tolerability of transcutaneous spinal direct current stimulation (tsDCS) in MDD. This was a double-blind, randomized, sham-controlled, parallel group, pilot clinical trial in unmedicated adults with moderate MDD. Twenty participants were randomly allocated (1:1 ratio) to receive "active" 2.5 mA or "sham" anodal tsDCS sessions with a thoracic (anode; T10)/right shoulder (cathode) electrode montage 3 times/week for 8 weeks. Change in depression severity (MADRS) scores (prespecified primary outcome) and secondary clinical outcomes were analyzed with ANOVA models. An E-Field model was generated using the active tsDCS parameters. Compared to sham (n = 9), the active tsDCS group (n = 10) showed a greater baseline to endpoint decrease in MADRS score with a large effect size (-14.6 ± 2.5 vs. -21.7 ± 2.3, p = 0.040, d = 0.86). Additionally, compared to sham, active tsDCS induced a greater decrease in MADRS "reported sadness" item (-1.8 ± 0.4 vs. -3.2 ± 0.4, p = 0.012), and a greater cumulative decrease in pre/post tsDCS session diastolic blood pressure change from baseline to endpoint (group difference: 7.9 ± 3.7 mmHg, p = 0.039). Statistical trends in the same direction were observed for MADRS "pessimistic thoughts" item and week-8 CGI-I scores. No group differences were observed in adverse events (AEs) and no serious AEs occurred. The current flow simulation showed electric field at strength within the neuromodulation range (max. ~0.45 V/m) reaching the thoracic spinal gray matter. The results from this pilot study suggest that tsDCS is feasible, well-tolerated, and shows therapeutic potential in MDD. This work also provides the initial framework for the cautious exploration of non-invasive spinal cord neuromodulation in the context of mental health research and therapeutics. The underlying mechanisms warrant further investigation. Clinicaltrials.gov registration: NCT03433339 URL: https://clinicaltrials.gov/ct2/show/NCT03433339 .

Functional MRI correlates of emotion regulation in major depressive disorder related to depressive disease load measured over nine years

Major Depressive Disorder (MDD) often is a recurrent and chronic disorder. We investigated the neurocognitive underpinnings of the incremental risk for poor disease course by exploring relations between enduring depression and brain functioning during regulation of negative and positive emotions using cognitive reappraisal. We used fMRI-data from the longitudinal Netherlands Study of Depression and Anxiety acquired during an emotion regulation task in 77 individuals with MDD. Task-related brain activity was related to disease load, calculated from presence and severity of depression in the preceding nine years. Additionally, we explored task related brain-connectivity. Brain functioning in individuals with MDD was further compared to 35 controls to explore overlap between load-effects and general effects related to MDD history/presence. Disease load was not associated with changes in affect or with brain activity, but with connectivity between areas essential for processing, integrating and regulating emotional information during downregulation of negative emotions. Results did not overlap with general MDD-effects. Instead, MDD was generally associated with lower parietal activity during downregulation of negative emotions. During upregulation of positive emotions, disease load was related to connectivity between limbic regions (although driven by symptomatic state), and connectivity between frontal, insular and thalamic regions was lower in MDD (vs controls). Results suggest that previous depressive load relates to brain connectivity in relevant networks during downregulation of negative emotions. These abnormalities do not overlap with disease-general abnormalities and could foster an incremental vulnerability to recurrence or chronicity of MDD. Therefore, optimizing emotion regulation is a promising therapeutic target for improving long-term MDD course.

Altered beta band spatial-temporal interactions during negative emotional processing in major depressive disorder: An MEG study

BACKGROUND

The mood-concordance bias is a key feature of major depressive disorder (MDD), but the spatiotemporal neural activity associated with emotional processing in MDD remains unclear. Understanding the dysregulated connectivity patterns during emotional processing and their relationship with clinical symptoms could provide insights into MDD neuropathology.

METHODS

We enrolled 108 MDD patients and 64 healthy controls (HCs) who performed an emotion recognition task during magnetoencephalography recording. Network-based statistics (NBS) was used to analyze whole-brain functional connectivity (FC) across different frequency ranges during distinct temporal periods. The relationship between the aberrant FC and affective symptoms was explored.

RESULTS

MDD patients exhibited decreased FC strength in the beta band (13-30 Hz) compared to HCs. During the early stage of emotional processing (0-100 ms), reduced FC was observed between the left parahippocampal gyrus and the left cuneus. In the late stage (250-400 ms), aberrant FC was primarily found in the cortex-limbic-striatum systems. Moreover, the FC strength between the right fusiform gyrus and left thalamus, and between the left calcarine fissure and left inferior temporal gyrus were negatively associated with Hamilton Depression Rating Scale (HAMD) scores.

LIMITATIONS

Medication information was not involved.

CONCLUSION

MDD patients exhibited abnormal temporal-spatial neural interactions in the beta band, ranging from early sensory to later cognitive processing stages. These aberrant interactions involve the cortex-limbic-striatum circuit. Notably, aberrant FC in may serve as a potential biomarker for assessing depression severity.

Brain Response of Major Depressive Disorder Patients to Emotionally Positive and Negative Music

Depression is characterized by poor emotion regulation that makes it difficult to escape the effects of emotional pain, but the neuromodulation behind these symptoms is still unclear. This study investigated the neural mechanism of emotional state-related responses during music stimuli in participants with major depressive disorder (MDD) compared to never-depressed (ND) controls. A novel two-level feature selection method, integrating recursive feature elimination based on support vector machine (SVM-RFE) and random forest algorithm (RF), was proposed to screen emotional recognition brain regions (ERBRs). On this basis, the differences of functional connectivity (FC) were systematically analyzed by two-sample t-test. The results demonstrate that ND participants show eight pairs of FCs with a significant difference between positive emotional music stimuli (pEMS) versus negative emotional music stimuli (nEMS) in 15 ERBRs of MDD, but the participants with MDD show one pair of significant difference in FC. The decreased number reflects the fuzzy response to positive and negative emotions in MDD, which appears to arise from obstacle to emotional cognition and regulation. Furthermore, there was no significant difference in FC between MDDs and NDs under pEMS, but a significant difference was detected between the two groups under nEMS (p < 0.01), revealing a 'bias' against the negative state in MDD. The current study may help to better comprehend the abnormal evolution from normal to depression and inform the utilization of pEMS in formal treatment for depression.

Normalization of impaired emotion inhibition in bipolar disorder mediated by cholinergic neurotransmission in the cingulate cortex

The muscarinic-cholinergic system is involved in the pathophysiology of bipolar disorder (BD), and contributes to attention and the top-down and bottom-up cognitive and affective mechanisms of emotional processing, functionally altered in BD. Emotion processing can be assessed by the ability to inhibit a response when the content of the image is emotional. Impaired regulatory capacity of cholinergic neurotransmission conferred by reduced M₂-autoreceptor availability is hypothesized to play a role in elevated salience of negative emotional distractors in euthymic BD relative to individuals with no history of mood instability. Thirty-three euthymic BD type-I (DSM-V-TR) and 50 psychiatrically-healthy controls underwent functional magnetic resonance imaging (fMRI) and an emotion-inhibition paradigm before and after intravenous cholinergic challenge using the acetylcholinesterase inhibitor, physostigmine (1 mg), or placebo. Mood, accuracy, and reaction time on either recognizing or inhibiting a response associated with an image involving emotion and regional functional activation were examined for effects of cholinergic challenge physostigmine relative to placebo, prioritizing any interaction with the diagnostic group. Analyses revealed that (1) at baseline, impaired behavioral performance was associated with lower activation in the anterior cingulate cortex in BD relative to controls during emotion processing; (2) physostigmine (vs. placebo) affected behavioral performance during the inhibition of negative emotions, without altering mood, and increased activation in the posterior cingulate cortex in BD (vs. controls); (3) In BD, lower accuracy observed during emotion inhibition of negative emotions was remediated by physostigmine and was associated with cingulate cortex overactivation. Our findings implicate abnormal regulation of cholinergic neurotransmission in the cingulate cortices in BD, which may mediate exaggerated emotional salience processing, a core feature of BD.

Avoiding monetary loss: A human habenula functional MRI ultra-high field study

A number of convergent human neuroimaging and animal studies suggest that habenula neurons fire in anticipation of non-rewarding outcomes, and suppress their firing in anticipation of rewarding outcomes. This normative function of the habenula appears disrupted in depression, and may be critical to the anti-depressant effects of ketamine. However, studying habenula functionality in humans using standard 3 T MRI is inherently limited by its small size. We employed ultra-high field (7 T) fMRI to investigate habenular activity in eighteen healthy volunteers during a Monetary Incentive Delay Task, focussing on loss avoidance, monetary loss and neutral events. We assessed neural activation in the field of view (FOV) in addition to ROI-based habenula-specific activity and generalized task-dependent functional connectivity. Whole FOV results indicated substantial neural differences between monetary loss and neutral outcomes, as well as between loss avoidance and neutral outcomes. Habenula-specific analyses showed bilateral deactivation during loss avoidance, compared to other outcomes. This first investigation into the habenula's role during loss avoidance revealed that the left habenula further differentiated between loss avoidance and monetary loss. Functional connectivity between the right habenula and the ipsilateral hippocampus and subcallosal cingulate (regions implicated in memory and depression pathophysiology) was enhanced when anticipating potential losses compared to anticipating neutral outcomes. Our findings suggest that the human habenula responds most strongly to outcomes of loss avoidance when compared to neutral and monetary losses, suggesting a role for the habenula in both reward and aversive processing. This has critical relevance to understanding the pathophysiology of habenula function in mood and other neuropsychiatric disorders, as well as the mechanism of action of habenula-targeting antidepressants such as ketamine.

Abnormal neural activities in adults and youths with major depressive disorder during emotional processing: a meta-analysis

BACKGROUND

Abnormal neural activities during emotional processing have been found in both adults and youths with major depressive disorder. However, findings were inconsistent in each group and cannot be compared to each other.

METHODS

We first identified neuroimaging experiments that revealed abnormal neural activities during emotional processing in patients with major depressive disorder published from January 1997 to January 2019. Then we conducted voxel-wise meta-analyses on adult and youth patients separately and compared the two age groups using direct meta-comparison.

RESULTS

Fifty-four studies comprising 1141 patients and 1242 healthy controls were identified. Both adult and youth patients showed abnormal neural activities in anterior cingulate cortex, insula, superior and middle temporal gyrus, and occipital cortex compared to healthy controls. However, hyperactivities in the superior and middle frontal gyrus, amygdala, and hippocampus were only observed in adult patients, while hyperactivity in the striatum was only found in youth patients compared to controls. In addition, compared with youths, adult patients exhibited significantly greater abnormal activities in insula, middle frontal gyrus, and hippocampus, and significantly lower abnormal activities in middle temporal gyrus, middle occipital gyrus, lingual gyrus, and striatum.

CONCLUSIONS

The common alterations confirmed the negative processing bias in major depressive disorder. Both adult and youth patients were suggested to have disturbed emotional perception, appraisal, and reactivity. However, adult patients might be more subject to the impaired appraisal and reactivity processes, while youth patients were more subject to the impaired perception process. These findings help us understand the progressive pathophysiology of major depressive disorder.

Fronto-limbic neuroimaging biomarkers for diagnosis and prediction of treatment responses in major depressive disorder

The neuroimaging is an important tool for understanding the biomarkers and predicting treatment responses in major depressive disorder (MDD). The potential biomarkers and prediction of treatment response in MDD will be addressed in the review article. The brain regions of cognitive control and emotion regulation, such as the frontal and limbic regions, might represent the potential targets for MDD biomarkers. The potential targets of frontal lobes might include anterior cingulate cortex (ACC), dorsolateral prefrontal cortex (DLPFC) and orbitofrontal cortex (OFC). For the limbic system, hippocampus and amygdala might be the potentially promising targets for MDD. The potential targets of fronto-limbic regions have been found in the studies of several major neuroimaging modalities, such as the magnetic resonance imaging, near-infrared spectroscopy, electroencephalography, positron emission tomography, and single-photon emission computed tomography. Additional regions, such as brainstem and midbrain, might also play a part in the MDD biomarkers. For the prediction of treatment response, the gray matter volumes, white matter tracts, functional representations and receptor bindings of ACC, DLPFC, OFC, amygdala, and hippocampus might play a role in the prediction of antidepressant responses in MDD. For the response prediction of psychotherapies, the fronto-limbic, reward regions, and insula will be the potential targets. For the repetitive transcranial magnetic stimulation, the DLPFC, ACC, limbic, and visuospatial regions might represent the predictive targets for treatment. The neuroimaging targets of MDD might be focused in the fronto-limbic regions. However, the neuroimaging targets for the prediction of treatment responses might be inconclusive and beyond the fronto-limbic regions.

Task MRI-Based Functional Brain Network of Major Depression

This chapter will focus on task magnetic resonance imaging (MRI) to understand the biological mechanisms and pathophysiology of brain in major depressive disorder (MDD), which would have minor alterations in the brain function. Therefore, the functional study, such as task MRI functional connectivity, would play a crucial role to explore the brain function in MDD. Different kinds of tasks would determine the alterations in functional connectivity in task MRI studies of MDD. The emotion-related tasks are linked with alterations in anterior cingulate cortex, insula, and default mode network. The emotional memory task is linked with amygdala-hippocampus alterations. The reward-related task would be related to the reward circuit alterations, such as fronto-straital. The cognitive-related tasks would be associated with frontal-related functional connectivity alterations, such as the dorsolateral prefrontal cortex, anterior cingulate cortex, and other frontal regions. The visuo-sensory characteristics of tasks might be associated with the parieto-occipital alterations. The frontolimbic regions might be major components of task MRI-based functional connectivity in MDD. However, different scenarios and tasks would influence the representations of results.

Amygdala: Neuroanatomical and Morphophysiological Features in Terms of Neurological and Neurodegenerative Diseases

The amygdala is one of the most discussed structures of the brain. Correlations between its level of activity, size, biochemical organization, and various pathologies are the subject of many studies, and can serve as a marker of existing or future disease. It is hypothesized that the amygdala is not just a structural unit, but includes many other regions in the brain. In this review, we present the updated neuroanatomical and physiological aspects of the amygdala, discussing its involvement in neurodegenerative and neurological diseases. The amygdala plays an important role in the processing of input signals and behavioral synthesis. Lesions in the amygdala have been shown to cause neurological disfunction of ranging severity. Abnormality in the amygdala leads to conditions such as depression, anxiety, autism, and also promotes biochemical and physiological imbalance. The amygdala collects pathological proteins, and this fact can be considered to play a big role in the progression and diagnosis of many degenerative diseases, such as Alzheimer’s disease, chronic traumatic encephalopathy, Lewy body diseases, and hippocampal sclerosis. The amygdala has shown to play a crucial role as a central communication system in the brain, therefore understanding its neuroanatomical and physiological features can open a channel for targeted therapy of neurodegenerative diseases.

Reconfiguration of Cortical Networks in MDD Uncovered by Multiscale Community Detection with fMRI

Major depressive disorder (MDD) is known to be associated with altered interactions between distributed brain regions. How these regional changes relate to the reorganization of cortical functional systems, and their modulation by antidepressant medication, is relatively unexplored. To identify changes in the community structure of cortical functional networks in MDD, we performed a multiscale community detection algorithm on resting-state functional connectivity networks of unmedicated MDD (uMDD) patients (n = 46), medicated MDD (mMDD) patients (n = 38), and healthy controls (n = 50), which yielded a spectrum of multiscale community partitions. we selected an optimal resolution level by identifying the most stable community partition for each group. uMDD and mMDD groups exhibited a similar reconfiguration of the community structure of the visual association and the default mode systems but showed different reconfiguration profiles in the frontoparietal control (FPC) subsystems. Furthermore, the central system (somatomotor/salience) and 3 frontoparietal subsystems showed strengthened connectivity with other communities in uMDD but, with the exception of 1 frontoparietal subsystem, returned to control levels in mMDD. These findings provide evidence for reconfiguration of specific cortical functional systems associated with MDD, as well as potential effects of medication in restoring disease-related network alterations, especially those of the FPC system.

Temporal dynamics of spontaneous default-mode network activity mediate the association between reappraisal and depression

Cognitive reappraisal is associated with major depressive disorder (MDD), while spontaneous activity patterns of the default mode network (DMN) is implicated in reappraisal and MDD. However, neural mechanisms subserving the close association of spontaneous reappraisal and depression are unclear. Spontaneous reappraisal, depression and resting-state functional magnetic resonance imaging (rsfMRI) were measured from 105 healthy subjects. We assessed the temporal complexity (Hurst exponent), Regional Homogeneity (ReHo) and fractional Amplitude of Low Frequency Fluctuation (fALFF) profiles of DMN, a network involved in both reappraisal and depression. Mediation effects of these standard measures on the relationship between reappraisal and depression, and the contributions of each DMN subregion, were assessed. Results indicated that Hurst exponent (H) of DMN, whether extracted by independent component analysis (ICA) or region of interest (ROI), was significantly associated with reappraisal scores. An individual with a higher reappraisal score has a lower Hurst value of DMN. Mediation analyses suggest that H of DMN partially mediates the association between reappraisal and the degree of depression, and this mediation effect arises from the contribution of medial prefrontal cortex. Neither ReHo nor fALFF showed a similar correlation or mediation effect. These findings suggest that temporal dynamics of DMN play an important role in emotion regulation and its association with depression. H of DMN may serve as a neural marker mediating the association between reappraisal and depression.

A comprehensive regional neurochemical theory in depression: a protocol for the systematic review and meta-analysis of 1H-MRS studies in major depressive disorder

BACKGROUND

Magnetic resonance spectroscopy (MRS) is a non-invasive analytical technique that investigates the presence and concentrations of brain metabolites. In the context of major depressive disorder (MDD), MRS has revealed regional biochemical changes in GABA, glutamate, and choline across different brain compartments. Technical and methodological advances in MRS data acquisition, in particular proton-based 1H-MRS, have resulted in a significant increase in the incidence of reports utilizing the technique for psychiatric disorder research and diagnosis. The most recent comprehensive meta-analysis reviewing MRS in MDD stems from 2006. Using contemporary systemic reviews and meta-analysis, the aim is to first test a neurochemical circuit-based theory of depression and then to determine if clinical scores relate to metabolite concentrations before and during treatment.

METHODS

Region-specific metabolite changes in MDD will be assessed by systematic review following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Inclusion criteria will include participant age (18 to 65), English language studies, known regions of interest, and detailed documentation of 1H-MRS procedures. Reported brain regions will be standardized according neuroanatomical expertise allowing increased power of the meta-analysis. Regions of interest will initially include the hippocampus, thalamus, prefrontal cortex, anterior and posterior cingulate gyri, parietal lobe, and basal ganglia. Exclusion criteria will include comorbid psychiatric illness and drug use. Two independent reviewers will undertake all data extraction, while a third reviewer will check for reviewer discrepancies. Statistical analysis will be performed using STATA supplemented by Metan software and SPSS.

DISCUSSION

This data will shed new light on the biochemical basis of depression in different brain regions, thereby highlighting the potential of MRS in identifying biomarkers and generating models of MDD and treatment response.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42018091494.

Abnormal changes in functional connectivity between the amygdala and frontal regions are associated with depression in Alzheimer's disease

PURPOSE

The aim of the present study was to investigate the functional connectivity (FC) of Alzheimer's disease patients with depression (D-AD) based on an amygdalar seed using resting-state functional magnetic resonance imaging (rs-fMRI).

METHODS

Twenty-one non-depressed AD (nD-AD) patients and 21 D-AD patients underwent rs-fMRI. The Hamilton Depression Rating Scale and Neuropsychiatric Inventory were used to evaluate the severity of depression. The amygdala was used as the seed for FC analysis. The FC differences between the two groups were evaluated by two-sample t tests, and the correlation of FC changes with depressive severity was analyzed by Pearson correlational analysis.

RESULTS

Compared with the nD-AD patients, D-AD patients had increased FC values between the amygdala and orbitofrontal cortex and decreased FC values among the amygdala, medial prefrontal cortex, and inferior frontal gyrus.

CONCLUSION

These data suggest that abnormal amygdala-prefrontal FC may be an important characteristic of AD patients with depression.

Emotion dysregulation and functional connectivity in children with and without a history of major depressive disorder

Recent interest has emerged in understanding the neural mechanisms by which deficits in emotion regulation (ER) early in development may relate to later depression. Corticolimbic alterations reported in emotion dysregulation and depression may be one possible link. We examined the relationships between emotion dysregulation in school age, corticolimbic resting-state functional connectivity (rs-FC) in preadolescence, and depressive symptoms in adolescence. Participants were 143 children from a longitudinal preschool onset depression study who completed the Children Sadness Management Scale (CSMS; measuring ER), Child Depression Inventory (CDI-C; measuring depressive symptoms), and two resting-state MRI scans. Rs-FC between four primary regions of interest (ROIs; bilateral dorsolateral prefrontal cortex [dlPFC] and amygdala) and six target ROIs thought to contribute to ER were examined. Findings showed that ER in school age did not predict depressive symptoms in adolescence, but did predict preadolescent increases in dlPFC-insula and dlPFC-ventromedial PFC rs-FC across diagnosis, as well as increased dlPFC-dorsal anterior cingulate cortex (dACC) rs-FC in children with a history of depression. Of these profiles, only dlPFC-dACC rs-FC in preadolescence predicted depressive symptoms in adolescence. However, dlPFC-dACC connectivity did not mediate the relationship between ER in school age and depressive symptoms in adolescence. Despite the absence of a direct relationship between ER and depressive symptoms and no significant rs-FC mediation, the rs-FC profiles predicted by ER are consistent with the hypothesis that emotion dysregulation is associated with abnormalities in top-down control functions. The extent to which these relationships might confer greater risk for later depression, however, remains unclear.

Epigenetic Changes of FKBP5 as a Link Connecting Genetic and Environmental Risk Factors with Structural and Functional Brain Changes in Major Depression

The gene for the glucocorticoid receptor regulator FK506 binding protein 5 (FKBP5) plays a role for risk, response to treatment, and changes in brain areas in major depressive disorder (MDD). Chronic stress is associated with lower methylation of FKBP5. Our aim was to investigate whether methylation of FKBP5 reflected exposure to childhood adversity in MDD and controls and whether it was associated with structure and function of emotional processing regions. FKBP5 intron 7 GR response element region methylation and rs1360780 allelic status were assessed from whole blood in 56 MDD adults and 50 controls. Using magnetic resonance imaging, we assessed gray matter concentration of selected areas and their function during valence recognition of emotional images. Childhood adversity was investigated using the Childhood Trauma Questionnaire. In MDD patients carrying the high-risk T allele of rs1360780, lower methylation of FKBP5 was predicted by childhood adversity (F=4.95, p=0.04). In all participants, lower FKBP5 intron methylation levels were associated with reduced gray matter concentration in the inferior frontal orbital gyrus bilaterally (Wald chi-square=11.93, p_FDR<0.01) and, in MDD, with its bilaterally higher activation during valence recognition (Wald chi-square=5.58, p=0.02). Activation of this region, regardless of side, was found to be lower in MDD compared to controls (Wald chi-square=3.88, p=0.049) and to be inversely correlated with depression severity (Wald chi-square=4.65, p=0.03). Our findings support the hypothesis that, in genetically predisposed individuals carrying a high-risk variant of the gene, childhood maltreatment might induce demethylation of FKBP5. This is in turn associated with structural and functional changes in the inferior frontal orbital gyrus, a relevant area for the clinical symptoms of MDD.