Patterns of reduced cortical thickness in late-life depression and relationship to psychotherapeutic response

Unraveling the causal relationships between depression and brain structural imaging phenotypes: A bidirectional Mendelian Randomization study

BACKGROUND

Previous studies have revealed structural brain abnormalities in individuals with depression, but the causal relationship between depression and brain structure remains unclear.

METHODS

A genetic correlation analysis was conducted using summary statistics from the largest genome-wide association studies for depression (N = 674,452) and 1,265 brain structural imaging-derived phenotypes (IDPs, N = 33,224). Subsequently, a bidirectional two-sample Mendelian Randomization (MR) approach was employed to explore the causal relationships between depression and the IDPs that showed genetic correlations with depression. The main MR results were obtained using the inverse variance weighted (IVW) method, and other MR methods were further employed to ensure the reliability of the findings.

RESULTS

Ninety structural IDPs were identified as being genetically correlated with depression and were included in the MR analyses. The IVW MR results indicated that reductions in the volume of several brain regions, including the bilateral subcallosal cortex, right medial orbitofrontal cortex, and right middle-posterior part of the cingulate cortex, were causally linked to an increased risk of depression. Additionally, decreases in surface area of the right middle temporal visual area, right middle temporal cortex, right inferior temporal cortex, and right middle-posterior part of the cingulate cortex were causally associated with a heightened risk of depression. Validation and sensitivity analyses supported the robustness of these findings. However, no evidence was found for a causal effect of depression on structural IDPs.

CONCLUSIONS

Our findings reveal the causal influence of specific brain structures on depression, providing evidence to consider brain structural changes in the etiology and treatment of depression.

Effects of electroconvulsive therapy on cortical thickness in depression: a systematic review

OBJECTIVE

Electroconvulsive therapy (ECT) is one of the most studied and validated available treatments for severe or treatment-resistant depression. However, little is known about the neural mechanisms underlying ECT. This systematic review aims to critically review all structural magnetic resonance imaging studies investigating longitudinal cortical thickness (CT) changes after ECT in patients with unipolar or bipolar depression.

METHODS

We performed a search on PubMed, Medline, and Embase to identify all available studies published before April 20, 2023. A total of 10 studies were included.

RESULTS

The investigations showed widespread increases in CT after ECT in depressed patients, involving mainly the temporal, insular, and frontal regions. In five studies, CT increases in a non-overlapping set of brain areas correlated with the clinical efficacy of ECT. The small sample size, heterogeneity in terms of populations, comorbidities, and ECT protocols, and the lack of a control group in some investigations limit the generalisability of the results.

CONCLUSIONS

Our findings support the idea that ECT can increase CT in patients with unipolar and bipolar depression. It remains unclear whether these changes are related to the clinical response. Future larger studies with longer follow-up are warranted to thoroughly address the potential role of CT as a biomarker of clinical response after ECT.

Grey matter volume predicts improvement in geriatric depression in response to Tai Chi compared to Health Education

OBJECTIVES

Geriatric depression (GD) is associated with cognitive impairment and brain atrophy. Tai-Chi-Chih (TCC) is a promising adjunct treatment to antidepressants. We previously found beneficial effects of TCC on resting state connectivity in GD. We now tested the effect of TCC on gray matter volume (GMV) change and the association between baseline GMV and clinical outcome.

PARTICIPANTS

Forty-nine participants with GD (>=60 y) underwent antidepressant treatment (38 women).

INTERVENTION

Participants completed 3 months of TCC (N = 26) or health and wellness education control (HEW; N = 23).

MEASUREMENTS

Depression and anxiety symptoms and MRI scans were acquired at baseline and 3-month follow-up. General linear models (GLMs) tested group-by-time interactions on clinical scores. Freesurfer 6.0 was used to process T1-weighted images and to perform voxel-wise whole-brain GLMs of group on symmetrized percent GMV change, and on the baseline GMV and symptom change association, controlling for baseline symptom severity. Age and sex served as covariates in all models.

RESULTS

There were no group differences in baseline demographics or clinical scores, symptom change from baseline to follow-up, or treatment-related GMV change. However, whole-brain analysis revealed that lower baseline GMV in several clusters in the TCC, but not the HEW group, was associated with larger improvements in anxiety. This was similar for right precuneus GMV and depressive symptoms.

CONCLUSIONS

While we observed no effect on GMV due to the interventions, baseline regional GMV predicted symptom improvements with TCC but not HEW. Longer trials are needed to investigate the long-term effects of TCC on clinical symptoms and neuroplasticity.

Regional gray matter volume correlates with anxiety, apathy, and resilience in geriatric depression

OBJECTIVES

Geriatric depression (GD) is associated with significant medical comorbidity, cognitive impairment, brain atrophy, premature mortality, and suboptimal treatment response. While apathy and anxiety are common comorbidities, resilience is a protective factor. Understanding the relationships between brain morphometry, depression, and resilience in GD could inform clinical treatment. Only few studies have addressed gray matter volume (GMV) associations with mood and resilience.

PARTICIPANTS

Forty-nine adults aged >60 years (38 women) with major depressive disorder undergoing concurrent antidepressant treatment participated in the study.

MEASUREMENTS

Anatomical T1-weighted scans, apathy, anxiety, and resilience data were collected. Freesurfer 6.0 was used to preprocess T1-weighted images and qdec to perform voxel-wise whole-brain analyses. Partial Spearman correlations controlling for age and sex tested the associations between clinical scores, and general linear models identified clusters of associations between GMV and clinical scores, with age and sex as covariates. Cluster correction and Monte-Carlo simulations were applied (corrected alpha = 0.05).

RESULTS

Greater depression severity was associated with greater anxiety (r = 0.53, p = 0.0001), lower resilience (r = -0.33, p = 0.03), and greater apathy (r = 0.39, p = 0.01). Greater GMV in widespread, partially overlapping clusters across the brain was associated with reduced anxiety and apathy, as well as increased resilience.

CONCLUSION

Our results suggest that greater GMV in extended brain regions is a potential marker for resilience in GD, while GMV in more focal and overlapping regions may be markers for depression and anxiety. Interventions focused on improving symptoms in GD may seek to examine their effects on these brain regions.

Lower Dorsal Lateral Prefrontal Cortex Functional Connectivity in Late-Life Depression With Suicidal Ideation

OBJECTIVE

The dorsal lateral prefrontal cortex (DLPFC) has been identified as a neuromodulation target for alleviating suicidal ideation. Dysfunctional DLPFC has been implicated in suicidality in depression. This study aimed to investigate the functional connectivity (FC) of the DLPFC in late-life depression (LLD) with suicidal ideation.

METHODS

Resting-state functional magnetic resonance imaging (fMRI) data from 32 LLD patients with suicidal ideation (LLD-S), 41 LLD patients without suicidal ideation (LLD-NS), and 54 healthy older adults (HOA) were analyzed using DLPFC seed-based FC analyses. Group differences in FC were examined, and machine learning was applied to explore the potential of DLPFC-FC for classifying LLD-S from LLD-NS.

RESULTS

Abnormal DLPFC-FC patterns were observed in LLD-S, characterized by lower connectivity with the angular gyrus, precuneus, and superior frontal gyrus compared to LLD-NS and healthy controls. A classification model based on the identified DLPFC-FC achieved an accuracy of 75%.

CONCLUSION

The lower FC of DLPFC networks may contribute to the neurobiological mechanism of suicidal ideation in late-life depression. These findings may facilitate suicide prevention for LLD by providing potential neuroimaging markers and network-based neuromodulation targets. However, further confirmation with larger sample sizes and experimental designs is warranted.

The heterogeneity of late-life depression and its pathobiology: a brain network dysfunction disorder

Depression is frequent in older individuals and is often associated with cognitive impairment and increasing risk of subsequent dementia. Late-life depression (LLD) has a negative impact on quality of life, yet the underlying pathobiology is still poorly understood. It is characterized by considerable heterogeneity in clinical manifestation, genetics, brain morphology, and function. Although its diagnosis is based on standard criteria, due to overlap with other age-related pathologies, the relationship between depression and dementia and the relevant structural and functional cerebral lesions are still controversial. LLD has been related to a variety of pathogenic mechanisms associated with the underlying age-related neurodegenerative and cerebrovascular processes. In addition to biochemical abnormalities, involving serotonergic and GABAergic systems, widespread disturbances of cortico-limbic, cortico-subcortical, and other essential brain networks, with disruption in the topological organization of mood- and cognition-related or other global connections are involved. Most recent lesion mapping has identified an altered network architecture with "depressive circuits" and "resilience tracts", thus confirming that depression is a brain network dysfunction disorder. Further pathogenic mechanisms including neuroinflammation, neuroimmune dysregulation, oxidative stress, neurotrophic and other pathogenic factors, such as β-amyloid (and tau) deposition are in discussion. Antidepressant therapies induce various changes in brain structure and function. Better insights into the complex pathobiology of LLD and new biomarkers will allow earlier and better diagnosis of this frequent and disabling psychopathological disorder, and further elucidation of its complex pathobiological basis is warranted in order to provide better prevention and treatment of depression in older individuals.

Multimodal Neural Evidence on the Corticostriatal Underpinning of Suicidality in Late-Life Depression

BACKGROUND

Suicidality involves thoughts (ideations and plans) and actions related to self-inflicted death. To improve management and prevention of suicidality, it is essential to understand the key neural mechanisms underlying suicidal thoughts and actions. Following empirically informed neural framework, we hypothesized that suicidal thoughts would be primarily characterized by alterations in the default mode network indicating disrupted self-related processing, whereas suicidal actions would be characterized by changes in the lateral prefrontal corticostriatal circuitries implicating compromised action control.

METHODS

We analyzed the gray matter volume and resting-state functional connectivity of 113 individuals with late-life depression, including 45 nonsuicidal patients, 33 with suicidal thoughts but no action, and 35 with past suicidal action. Between-group analyses revealed key neural features associated with suicidality. The functional directionality of the identified resting-state functional connectivity was examined using dynamic causal modeling to further elucidate its mechanistic nature. Post hoc classification analysis examined the contribution of the neural measures to suicide classification.

RESULTS

As expected, reduced gray matter volumes in the default mode network and lateral prefrontal regions characterized patients with suicidal thoughts and those with past suicidal actions compared with nonsuicidal patients. Furthermore, region-of-interest analyses revealed that the directionality and strength of the ventrolateral prefrontal cortex-caudate resting-state functional connectivity were related to suicidal thoughts and actions. The neural features significantly improved classification of suicidal thoughts and actions over that based on clinical and suicide questionnaire variables.

CONCLUSIONS

Gray matter reductions in the default mode network and lateral prefrontal regions and the ventrolateral prefrontal cortex-caudate connectivity alterations characterized suicidal thoughts and actions in patients with late-life depression.

Auditory Verb Generation Performance Patterns Dissociate Variants of Primary Progressive Aphasia

Primary progressive aphasia (PPA) is a clinical syndrome in which patients progressively lose speech and language abilities. Three variants are recognized: logopenic (lvPPA), associated with phonology and/or short-term verbal memory deficits accompanied by left temporo-parietal atrophy; semantic (svPPA), associated with semantic deficits and anterior temporal lobe (ATL) atrophy; non-fluent (nfvPPA) associated with grammar and/or speech-motor deficits and inferior frontal gyrus (IFG) atrophy. Here, we set out to investigate whether the three variants of PPA can be dissociated based on error patterns in a single language task. We recruited 21 lvPPA, 28 svPPA, and 24 nfvPPA patients, together with 31 healthy controls, and analyzed their performance on an auditory noun-to-verb generation task, which requires auditory analysis of the input, access to and selection of relevant lexical and semantic knowledge, as well as preparation and execution of speech. Task accuracy differed across the three variants and controls, with lvPPA and nfvPPA having the lowest and highest accuracy, respectively. Critically, machine learning analysis of the different error types yielded above-chance classification of patients into their corresponding group. An analysis of the error types revealed clear variant-specific effects: lvPPA patients produced the highest percentage of "not-a-verb" responses and the highest number of semantically related nouns (production of baseball instead of throw to noun ball); in contrast, svPPA patients produced the highest percentage of "unrelated verb" responses and the highest number of light verbs (production of take instead of throw to noun ball). Taken together, our findings indicate that error patterns in an auditory verb generation task are associated with the breakdown of different neurocognitive mechanisms across PPA variants. Specifically, they corroborate the link between temporo-parietal regions with lexical processing, as well as ATL with semantic processes. These findings illustrate how the analysis of pattern of responses can help PPA phenotyping and heighten diagnostic sensitivity, while providing insights on the neural correlates of different components of language.

Differences in electric field strength between clinical and non-clinical populations induced by prefrontal tDCS: A cross-diagnostic, individual MRI-based modeling study

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MDD and SCZ showed lower prefrontal tDCS-induced e-field strengths compared to HC.

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Average e-field strengths did not significantly differ between MDD and SCZ patients.

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Inter-individual variability of e-field intensities and distribution was prominent.

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Inter-rater variability emphasizes the importance of standardized positioning.

Introduction

Prefrontal cortex (PFC) regions are promising targets for therapeutic applications of non-invasive brain stimulation, e.g. transcranial direct current stimulation (tDCS), which has been proposed as a novel intervention for major depressive disorder (MDD) and negative symptoms of schizophrenia (SCZ). However, the effects of tDCS vary inter-individually, and dose–response relationships have not been established. Stimulation parameters are often tested in healthy subjects and transferred to clinical populations. The current study investigates the variability of individual MRI-based electric fields (e-fields) of standard bifrontal tDCS across individual subjects and diagnoses.

Method

The study included 74 subjects, i.e. 25 patients with MDD, 24 patients with SCZ, and 25 healthy controls (HC). Individual e-fields of a common tDCS protocol (i.e. 2 mA stimulation intensity, bifrontal anode-F3/cathode-F4 montage) were modeled by two investigators using SimNIBS (2.0.1) based on structural MRI scans.

Result

On a whole-brain level, the average e-field strength was significantly reduced in MDD and SCZ compared to HC, but MDD and SCZ did not differ significantly. Regions of interest (ROI) analysis for PFC subregions showed reduced e-fields in Sallet areas 8B and 9 for MDD and SCZ compared to HC, whereas there was again no difference between MDD and SCZ. Within groups, we generally observed high inter-individual variability of e-field intensities at a higher percentile of voxels.

Conclusion

MRI-based e-field modeling revealed significant differences in e-field strengths between clinical and non-clinical populations in addition to a general inter-individual variability. These findings support the notion that dose–response relationships for tDCS cannot be simply transferred from healthy to clinical cohorts and need to be individually established for clinical groups. In this respect, MRI-based e-field modeling may serve as a proxy for individualized dosing.

Imaging correlates of depression in progressive supranuclear palsy

Depression is highly common in Progressive Supranuclear Palsy (PSP) and is a meaningful determinant of quality of life. However, neurobiological and neuroimaging correlates of this neuropsychiatric disturbance in PSP patients are still unknown. In this study, we aimed to investigate the topographical distribution of morphometric changes associated with depression in PSP patients using cortical thickness. Forty patients with PSP were evaluated at baseline with clinical rating scales and MRI scans. Based on the response to the 15-item Geriatric Depression Scale we identified 21 PSP patients with depression (GDS-15 score ≥ 5) and 19 PSP patients without depression (GDS-15 score < 5). In vertex-wise analysis, comparison of cortical thickness between PSP patients with and without depression was performed using a general linear model. PSP patients with depressions showed reduced cortical thickness in temporo-parieto-occipital areas, more pronounced in the right hemisphere. These findings propose neurobiological conceptualizations of depression in PSP as being associated with a multiregional pattern of morphometric grey matter reduction.

Age-dependent brain morphometry in Major Depressive disorder

BACKGROUND

Major depressive disorder (MDD) is a complex disorder that affects nearly 264 million people worldwide. Structural brain abnormalities in multiple neuroanatomical networks have been implicated in the etiology of MDD, but the degree to which MDD affects brain structure during early to late adulthood is unclear.

METHODS

We examined morphometry of brain regions commonly implicated in MDD, including the amygdala, hippocampus, anterior cingulate gyrus, lateral orbitofrontal gyrus, subgenual cortex, and insular cortex subregions, from early to late adulthood. Harmonized measures for gray matter (GM) volume and cortical thickness of each region were estimated cross-sectionally for 305 healthy controls (CTLs) and 247 individuals with MDD (MDDs), collated from four research cohorts. We modeled the nonlinear associations of age with GM volume and cortical thickness using generalized additive modeling and tested for age-dependent group differences.

RESULTS

Overall, all investigated regions exhibited smaller GM volume and thinner cortical measures with increasing age. Compared to age matched CTLs, MDDs had thicker cortices and greater GM volume from early adulthood until early middle age (average 35 years), but thinner cortices and smaller GM volume during and after middle age in the lateral orbital gyrus and all insular subregions. Deviations of the MDD and CTL models for both GM volume and cortical thickness in these regions started as early as age 18.

CONCLUSIONS

The analyses revealed that brain morphometry differences between MDDs and CTLs are dependent on age and brain region. The significant age-by-group interactions in the lateral orbital frontal gyrus and insular subregions make these regions potential targets for future longitudinal studies of MDD.

Cortical thickness predicts remission of depression with antidepressants in patients with late-life depression and cognitive impairment

BACKGROUND

Depression (DEP) and cognitive impairment (CI) share etiological risk factors, anatomical underpinnings, and interact to produce deleterious treatment outcomes. Both DEP and CI exhibit altered patterns of cortical thickness which may impact the course of antidepressant treatment, though inconsistencies in directionality and affected brain regions have been reported. In this study, we examined the relationship between cortical thickness and treatment outcome in older adults with comorbid DEP-CI.

METHODS

55 patients with DEP-CI received baseline MRI scans as part of a larger clinical trial at NYSPI/Columbia University Medical Center and Duke University Medical Center. Mood was assessed using the Hamilton Depression Rating Scale. Patients received open antidepressant treatment for 8 weeks followed by another 8 weeks of the same medication or switch to another antidepressant for a total of 16 weeks. Cortical thickness was extracted using an automated brain segmentation program (FreeSurfer). Vertex-wise analyses evaluated the relationship between cortical thickness and treatment outcome.

RESULTS

Remitters exhibited diffuse clusters of greater cortical thickness and reduced cortical thickness compared to non-remitters. Thicker baseline middle frontal gyrus most consistently predicted greater likelihood and faster rate of remission. White matter hyperintensities and hippocampal volume were not associated with antidepressant treatment outcome.

LIMITATIONS

MRI was conducted at baseline only and sample size was small.

DISCUSSION

Cortical thickness predicts treatment remission and magnitude of early improvement. Results indicate that individuals with DEP-CI exhibit unique patterns of structural abnormalities compared to their depressed peers without CI that have consequences for their recovery with antidepressant treatment.

Orbito-frontal thinning together with a somatoform dissociation might be the fingerprint of PNES

OBJECTIVE

To investigate neuroanatomical changes in patients with psychogenic nonepileptic seizures (PNES) compared to major depressive disorder (MDD) and healthy controls.

METHODS

Forty-two drug-naïve PNES subjects and 25 patients with MDD, matched for demographic characteristics and level of depression (as measured by Beck Depression Inventory-II, BDI-II), were consecutively recruited. Patients performed an extensive neuropsychiatric assessment including: Hamilton Anxiety Rating Scale, Traumatic Experience Checklist, Dissociative Experiences Scale, Toronto Alexithymia Scale and Somatoform Dissociation Questionnaire (SDQ-20). All patients, together with 78 healthy matched controls, underwent 3T brain MRI followed by surface-based morphometry.

RESULTS

Cortical thickness analysis revealed significant cortical thinning in bilateral medial orbitofrontal cortex (OFC) and left rostral anterior cingulate cortex (ACC) in patients with MDD compared to subjects with PNES and controls. Interestingly, increased thickness of the right pars triangularis was found in PNES subjects compared to controls. PNES showed higher scores in SDQ-20 (p < 0.001) compared to MDD, which was corroborated by neuroimaging data, where somatoform dissociation scores correlated with morphological changes in the left medial OFC.

CONCLUSION

Our results show selective cortical thinning over the medial OFC in patients with PNES compared to wider regions of thinning in patients with MDD. Somatoform dissociation was the only psychopathological assessment significantly different in PNES and MDD.

Cortical Thickness and Hippocampal Volume in Vascular and Non-vascular Depressed Patients

Background: Reduced cortical thickness and hippocampal volume are prevalent markers of late life depression as well as mild cognitive impairment (MCI) but are conspicuously absent in the vascular depression (VD) literature. The present study aimed to determine differences in cortical thickness and hippocampal volume between VD and non-VD patients. Methods: Participants were enrolled in an 8-week open treatment antidepressant trial. Forty-one depressed individuals aged 50 and older underwent brain magnetic resonance imaging at baseline and were classified as VD or non-VD. Cortical thickness values for the left and right entorhinal, parahippocampal, and precuneal cortices, as well as left and right hippocampal volume, were linearly regressed on VD status to determine mean differences between VD and non-VD. Covariates included site, age, sex, and mean thickness or intracranial volume. Results: No statistical differences were found between VD and non-VD patients in cortical thickness of the bilateral precuneal, entorhinal, or parahippocampal cortices, or hippocampal volume (p > 0.001). Conclusions: The absence of statistical differences in gray matter between VD and non-VD patients raises several diagnostic, etiological, and developmental possibilities, namely that VD may not be connected with other late-life psychiatric illnesses such as MCI or dementia and that vascular disease may not be a common etiological risk factor for depression and dementia. Larger datasets, prospective longitudinal studies, and cognitively intact controls are needed to further address these types of questions.

Effects of polygenic risk for major mental disorders and cross-disorder on cortical complexity

BACKGROUND

MRI-derived cortical folding measures are an indicator of largely genetically driven early developmental processes. However, the effects of genetic risk for major mental disorders on early brain development are not well understood.

METHODS

We extracted cortical complexity values from structural MRI data of 580 healthy participants using the CAT12 toolbox. Polygenic risk scores (PRS) for schizophrenia, bipolar disorder, major depression, and cross-disorder (incorporating cumulative genetic risk for depression, schizophrenia, bipolar disorder, autism spectrum disorder, and attention-deficit hyperactivity disorder) were computed and used in separate general linear models with cortical complexity as the regressand. In brain regions that showed a significant association between polygenic risk for mental disorders and cortical complexity, volume of interest (VOI)/region of interest (ROI) analyses were conducted to investigate additional changes in their volume and cortical thickness.

RESULTS

The PRS for depression was associated with cortical complexity in the right orbitofrontal cortex (right hemisphere: p = 0.006). A subsequent VOI/ROI analysis showed no association between polygenic risk for depression and either grey matter volume or cortical thickness. We found no associations between cortical complexity and polygenic risk for either schizophrenia, bipolar disorder or psychiatric cross-disorder when correcting for multiple testing.

CONCLUSIONS

Changes in cortical complexity associated with polygenic risk for depression might facilitate well-established volume changes in orbitofrontal cortices in depression. Despite the absence of psychopathology, changed cortical complexity that parallels polygenic risk for depression might also change reward systems, which are also structurally affected in patients with depressive syndrome.

Neural substrates for late-life depression: A selective review of structural neuroimaging studies

Recent neuroimaging studies have characterized the pathophysiology of late-life depression (LLD) as a dysfunction of the brain networks involved in the regulation of emotion, motivational behavior, cognitive control, executive function, and self-referential thinking. In this article, we reviewed LLD-associated structural neuroimaging markers such as white matter hyperintensity (WMH), white matter integrity measured by diffusion tensor imaging, cortical and subcortical volumes, and cortical thickness, which may provide a structural basis for brain network dysfunction in LLD. LLD was associated with greater severity or volumes of deep, periventricular, or overall WMH and with decreased white matter integrity in the brain regions belonging to the fronto-striatal-limbic circuits and reduced white matter tract integrity which connects these circuits, such as the cingulum, corpus callosum, or uncinate fasciculus. Decreased volumes or cortical thickness in the prefrontal cortex, orbitofrontal cortex, anterior and posterior cingulate cortex, several temporal and parietal regions, hippocampus, amygdala, striatum, thalamus, and the insula were associated with LLD. These structural neuroimaging findings were also associated with cognitive dysfunction, which is a prominent clinical feature in LLD. Several structural neuroimaging markers including the WMH burden, white matter integrity, and cortical and subcortical volumes predicted antidepressant response in LLD. These structural neuroimaging findings support the hypothesis that disruption of the brain networks involved in emotion regulation and cognitive processing by impaired structural connectivity is strongly associated with the pathophysiology of LLD.

A performance-based measure of emotion response control: A preliminary MRI study

Identifying performance-based assessments of emotion regulation is needed for the study of myriad mood and neurological disorders. Color and form responses on the Rorschach Inkblot Method are valid measures of emotion response control, but have not been studied in relation to known neural correlations of emotion regulation. A discrepancy of color (CF + C) greater than form (FC) responses suggests low cognitive control over emotional responses. This preliminary report explores the discrepancy between form-color responses as a correlate of regional cortical thickness. A sample of community-dwelling adults were administered the Rorschach Inkblot Method and participated in a structural MRI scan. Greater middle frontal cortex thickness was associated with a positive discrepancy score [(CF + C) - FC], indicating less emotion response control (r_s  = 0.48, p < 0.05); a moderate, non-significant correlation was also observed with insula cortex (r_s  = 0.42, p = 0.07).The results provide evidence in support of the Rorschach Inkblot Method as a valid behavioral measure of emotion response control. More specifically, these results support the use of color-related variables included in contemporary evidence-based Rorschach methods. The results are discussed with implications for the study of emotion regulation in mood disorders and sensitivity analyses based on the observed effect sizes are reported to inform future study planning.

Depression Severity, but Not Cognitive Impairment or Frailty, is Associated with Disability in Late-Life Depression

OBJECTIVES

Assess the relationship of cognitive impairment to disability, accounting for depression severity and frailty, among older adults with late-life depression (LLD).

METHODS

Data were analyzed from 78 community-dwelling older adults with LLD and without dementia (age M = 71.9; SD = 6.1). Cognitive functioning was assessed using a comprehensive neuropsychological battery. Depression severity was measured using the 17-item Hamilton Depression Rating Scale (HDRS; cutoff ≥15). Frailty was assessed using several motor tests. The World Health Organization Disability Assessment Schedule (WHO-DAS) measured disability status. A linear regression analysis was performed to identify relationships of cognition, frailty and depression severity with disability.

RESULTS

The average number of impaired cognitive tests was 2.0 (SD = 1.9), with 28.2% of participants showing no impaired scores. On average participants reported depression severity of 17.3 (SD = 3.6), and disability total score of 15.1 (SD = 6.9). The regression model accounted for 25.1% of the variance in disability, with only depression severity significantly predicting disability status. Burden of cognitive impairment and frailty were not predictive of disability in this sample.

CONCLUSIONS

In this sample, only depression severity was associated with increased disability.

CLINICAL IMPLICATIONS

These findings have implications for intervention in LLD, as depression severity may represent a more modifiable risk factor for disability.

Cortical thickness increases with levomilnacipran treatment in a pilot randomised double-blind placebo-controlled trial in late-life depression

BACKGROUND

Late-life depression (LLD) is associated with significant medical comorbidity, cognitive impairment, and suboptimal treatment response compared to depression experienced earlier in life. Levomilnacipran (LVM) is a novel antidepressant the effects of which on neuroplasticity have not yet been investigated. We investigated the effect of LVM on cortical thickness in a pilot randomised placebo-controlled trial in LLD.

METHODS

Twenty-nine adults (≥ 60 years) with major depression (48.3% female; mean age = 71.5 ± 5.8 years; mean education = 16.0 ± 1.7 years) were randomised to either LVM or placebo for 12 weeks. T1-weighted images were acquired at baseline and 12 weeks. Thirteen subjects (six LVM and seven placebo) completed the study. Group differences in cortical thickness change across the study period were evaluated, with age and total intracranial volume included as covariates.

RESULTS

Dropout rates did not differ significantly between groups. The LVM group had significantly more side effects, but no serious adverse events were reported. Lower LVM dose (≤ 40 mg) was better tolerated than higher doses (80-120 mg). Additionally, the LVM group showed a larger increase in cortical thickness in the right postcentral gyrus (primary somatosensory), supramarginal gyrus (sensory association region), and lateral occipital cortex (visual cortex) compared to the placebo group and greater reductions in the left insula.

CONCLUSIONS

LVM may be less tolerable by older adults with depression and the effects on cortical thickness across sensory and sensory association regions may be related to the experience of side effects. Larger studies are necessary to evaluate treatment efficacy, tolerability, and neural effects of LVM in LLD.

Increases in orbitofrontal cortex thickness following antidepressant treatment are associated with changes in resting state autonomic function in adolescents with major depression - Preliminary findings from a pilot study

In adults with major depressive disorder (MDD), effective treatment has been associated with increases in both heart rate variability (HRV) and cortical thickness. However, the impact of treatment on these indices has not yet been examined in adolescents. Cortical thickness and HRV were measured in twelve adolescents with MDD before and after 8 weeks of treatment with a selective serotonin reuptake inhibitor (SSRI). We examined treatment-related changes in depression symptoms, HRV, heart rate (HR), and cortical thickness, and analyzed correlations among these change indices. At follow-up, patients showed significantly decreased depression severity, increased HRV and increased thickness of the left medial orbitofrontal cortex (OFC). Clinical improvement was associated with increased HRV and decreased HR. Increased HRV was associated with increased cortical thickness of left lateral OFC and superior frontal cortex. Due to the small sample size, results represent preliminary findings that need replication. Further, in the absence of a placebo arm, we cannot confirm that the observed effects are due solely to medication. These preliminary findings suggest that SSRI treatment in adolescents impacts both cortical thickness and autonomic functioning. Confirmation of these findings would support OFC thickness and HRV as neurobiological mediators of treatment outcome.

Development and evaluation of a multimodal marker of major depressive disorder

This study aimed to identify biomarkers of major depressive disorder (MDD), by relating neuroimage-derived measures to binary (MDD/control), ordinal (severe MDD/mild MDD/control), or continuous (depression severity) outcomes. To address MDD heterogeneity, factors (severity of psychic depression, motivation, anxiety, psychosis, and sleep disturbance) were also used as outcomes. A multisite, multimodal imaging (diffusion MRI [dMRI] and structural MRI [sMRI]) cohort (52 controls and 147 MDD patients) and several modeling techniques-penalized logistic regression, random forest, and support vector machine (SVM)-were used. An additional cohort (25 controls and 83 MDD patients) was used for validation. The optimally performing classifier (SVM) had a 26.0% misclassification rate (binary), 52.2 ± 1.69% accuracy (ordinal) and r = .36 correlation coefficient (p < .001, continuous). Using SVM, R² values for prediction of any MDD factors were <10%. Binary classification in the external data set resulted in 87.95% sensitivity and 32.00% specificity. Though observed classification rates are too low for clinical utility, four image-based features contributed to accuracy across all models and analyses-two dMRI-based measures (average fractional anisotropy in the right cuneus and left insula) and two sMRI-based measures (asymmetry in the volume of the pars triangularis and the cerebellum) and may serve as a priori regions for future analyses. The poor accuracy of classification and predictive results found here reflects current equivocal findings and sheds light on challenges of using these modalities for MDD biomarker identification. Further, this study suggests a paradigm (e.g., multiple classifier evaluation with external validation) for future studies to avoid nongeneralizable results.

The relationship of impulsivity and cortical thickness in depressed and non-depressed adolescents

Major Depressive Disorder (MDD) is recognized to be heterogeneous in terms of brain structure abnormality findings across studies, which might reflect previously unstudied traits that confer variability to neuroimaging measurements. The purpose of this study was to examine the relationships between different types of trait impulsivity and MDD diagnosis on adolescent brain structure. We predicted that adolescents with depression who were high on trait impulsivity would have more abnormal cortical structure than depressed patients or non-MDD who were low on impulsivity. We recruited 58 subjects, including 29 adolescents (ages 12-19) with a primary DSM-IV diagnosis of MDD and a history of suicide attempt and 29 demographically-matched healthy control participants. Our GLM-based analyses sought to describe differences in the linear relationships between cortical thickness and impulsivity trait levels. As hypothesized, we found significant moderation effects in rostral middle frontal gyrus and right paracentral lobule cortical thickness for different subscales of the Barratt Impulsiveness Scale. However, although these brain-behavior relationships differed between diagnostic study groups, they were not simple additive effects as we had predicted. For the middle frontal gyrus, non-MDD participants showed a strong positive association between cortical thickness and BIS-11 Motor scores, while MDD-diagnosed participants showed a negative association. For Non-Planning Impulsiveness, paracentral lobule cortical thickness was observed with greater impulsivity in MDD, but no association was found for controls. In conclusion, the findings confirm that dimensions of impulsivity have discrete neural correlates, and show that relationships between impulsivity and brain structure are expressed differently in adolescents with MDD compared to non-MDD.

Cortical Thickness and Depressive Symptoms in Cognitively Normal Individuals: The Mayo Clinic Study of Aging

Altered cortical thickness has been observed in aging and various neurodegenerative disorders. Furthermore, reduced hippocampal volume has been reported in late-life depression. Even mild depressive symptoms are common in the elderly. However, little is known about the structural MRI measures of depressive symptoms in normal cognitive aging. Thus we sought to examine the association between depressive symptoms with cortical thickness and hippocampal volume as measured by brain MRI among community-dwelling participants. We conducted a cross-sectional study derived from the ongoing population-based Mayo Clinic Study of Aging, involving cognitively normal participants (N = 1,507) aged≥70 years. We observed that depressive symptoms were associated with lower global cortical thickness and lower thickness in specific prefrontal and temporal cortical regions, labeled by FreeSurfer software, version 5.3. As expected, the strength of correlation was very small, given that participants were community-dwelling with only mild depressive symptoms. We did not observe associations between hippocampal volume and depressive symptoms. These findings may provide insight into the structural correlates of mild depressive symptoms in elderly participants.

Predictive Neuroimaging Markers of Psychotherapy Response: A Systematic Review

INTRODUCTION

Predictive neuroimaging markers of treatment response are increasingly sought in order to inform the treatment of major depressive and anxiety disorders. We review the existing literature regarding candidate predictive neuroimaging markers of psychotherapy response and assess their potential clinical utility.

METHODS

We searched Embase, PsycINFO, and PubMed up to October 2014 for studies correlating pretreatment neuroimaging parameters with psychotherapy response in major depressive and anxiety disorders. Our search yielded 40 eligible studies.

RESULTS

The anterior cingulate cortex, amygdala, and anterior insula emerged as potential markers in major depressive disorder and some anxiety disorders. Results across studies displayed a large degree of variability, however, and to date the findings have not been systematically validated in independent clinical cohorts and have not been shown capable of distinguishing between medication and psychotherapy responders. Also limited is the examination of how neuroimaging compares or might add to other prognostic clinical variables.

CONCLUSION

While the extant data suggest avenues of further investigation, we are still far from being able to use these markers clinically. Future studies need to focus on longitudinal testing of potential markers, determining their prescriptive value and examining how they might be integrated with clinical factors.

A population study of Norwegian psychiatric patients referred for clinical brain scanning

BACKGROUND

Patients with psychiatric conditions are often referred for a brain scan during the course of their diagnostic workup.

AIMS

The aim of our study is to determine frequency and type of organic brain pathology, the relationship to age, gender and psychiatric diagnosis.

METHOD

We investigated magnetic resonance imaging and computed tomography brain scans from consecutively referred patients over a 10-year period (January 2002-December 2011). The reasons for referral, estimated psychiatric diagnosis, and the pathology discovered for each patient were registered.

RESULTS

A total of 34% of patients demonstrated organic brain pathology, of which 32.8% were considered clinically relevant. This represents a higher frequency of relevant pathology than reported in healthy subjects. Age (P < 0.001) and diagnosis (P = 0.016) were the most important determinants for frequency of pathological findings.

CONCLUSIONS

Brain imaging in clinical psychiatry resulted in approximately 30% positive findings mainly associated with increasing pathologies with age, but also with diagnosis.

DECLARATION OF INTEREST

Both T.O.D. and M.K.B. have received honorary from Novartis for scientific lectures about multiple sclerosis. M.K.B. also received honoraria from Biogen for scientific lectures. The other authors have no conflicts of interest.

Perceived stress is associated with increased rostral middle frontal gyrus cortical thickness: a family-based and discordant-sibling investigation

Elevated stress perception and depression commonly co-occur, suggesting that they share a common neurobiology. Cortical thickness of the rostral middle frontal gyrus (RMFG), a region critical for executive function, has been associated with depression- and stress-related phenotypes. Here, we examined whether RMFG cortical thickness is associated with these phenotypes in a large family-based community sample. RMFG cortical thickness was estimated using FreeSurfer among participants (n = 879) who completed the ongoing Human Connectome Project. Depression-related phenotypes (i.e. sadness, positive affect) and perceived stress were assessed via self-report. After accounting for sex, age, ethnicity, average whole-brain cortical thickness, twin status and familial structure, RMFG thickness was positively associated with perceived stress and sadness and negatively associated with positive affect at small effect sizes (accounting for 0.2-2.4% of variance; p-fdr: 0.0051-0.1900). Perceived stress was uniquely associated with RMFG thickness after accounting for depression-related phenotypes. Further, among siblings discordant for perceived stress, those reporting higher perceived stress had increased RMFG thickness (P = 4 × 10^-7 ). Lastly, RMFG thickness, perceived stress, depressive symptoms, and positive affect were all significantly heritable, with evidence of shared genetic and environmental contributions between self-report measures. Stress perception and depression share common genetic, environmental, and neural correlates. Variability in RMFG cortical thickness may play a role in stress-related depression, although effects may be small in magnitude. Prospective studies are required to examine whether variability in RMFG thickness may function as a risk factor for stress exposure and/or perception, and/or arises as a consequence of these phenotypes.

Cortical Atrophy is Associated with Accelerated Cognitive Decline in Mild Cognitive Impairment with Subsyndromal Depression

OBJECTIVES

To investigate the association between cognitive decline and cortical atrophy in individuals with mild cognitive impairment (MCI) and chronic subsyndromal symptoms of depression (SSD) over a 4-year period.

DESIGN

Prospective cohort study.

SETTING

Multicenter, clinic-based.

PARTICIPANTS

Within the Alzheimer's Disease Neuroimaging Initiative repository, the Neuropsychiatric Inventory was used to identify individuals with MCI and stable endorsement (SSD group N = 32) or no endorsement (non-SSD group N = 69) of depressive symptoms across time points.

MEASUREMENTS

Repeated measures of cognitive outcomes, cortical atrophy, and their associations were evaluated with mixed effects models adjusting for age, education, sex, and APOE genotype.

RESULTS

The SSD group demonstrated accelerated decline on measures of global cognition (Alzheimer Disease Assessment Scale; df = 421, t = 2.242, p = 0.025), memory (Wechsler Memory Scale-Revised Logical Memory II; df = 244, t = -2.525, p = 0.011), information processing speed (Trail Making Test Parts A [df = 421, t = 2.376, p = 0.018] and B [df = 421, t = 2.533, p = 0.012]), and semantic fluency (Category Fluency; df = 424, t = -2.418, p = 0.016), as well as accelerated frontal lobe (df = 341, t = -2.648, p = 0.008) and anterior cingulate (df = 341, t = -3.786, p < 0.001) atrophy. No group differences were observed for rate of decline on measures of attention, learning, and confrontation naming or for rate of atrophy in any other regions. Accelerated frontal lobe and anterior cingulate atrophy was associated with cognitive decline on measures of global cognition, information processing speed, and semantic fluency (all p < 0.05), but not memory.

CONCLUSIONS

Individuals with chronic SSD may represent an MCI subgroup that is highly vulnerable to accelerated cognitive decline, an effect that may be governed by frontal lobe and anterior cingulate atrophy.

Cortical abnormalities in adults and adolescents with major depression based on brain scans from 20 cohorts worldwide in the ENIGMA Major Depressive Disorder Working Group

The neuro-anatomical substrates of major depressive disorder (MDD) are still not well understood, despite many neuroimaging studies over the past few decades. Here we present the largest ever worldwide study by the ENIGMA (Enhancing Neuro Imaging Genetics through Meta-Analysis) Major Depressive Disorder Working Group on cortical structural alterations in MDD. Structural T1-weighted brain magnetic resonance imaging (MRI) scans from 2148 MDD patients and 7957 healthy controls were analysed with harmonized protocols at 20 sites around the world. To detect consistent effects of MDD and its modulators on cortical thickness and surface area estimates derived from MRI, statistical effects from sites were meta-analysed separately for adults and adolescents. Adults with MDD had thinner cortical gray matter than controls in the orbitofrontal cortex (OFC), anterior and posterior cingulate, insula and temporal lobes (Cohen's d effect sizes: -0.10 to -0.14). These effects were most pronounced in first episode and adult-onset patients (>21 years). Compared to matched controls, adolescents with MDD had lower total surface area (but no differences in cortical thickness) and regional reductions in frontal regions (medial OFC and superior frontal gyrus) and primary and higher-order visual, somatosensory and motor areas (d: -0.26 to -0.57). The strongest effects were found in recurrent adolescent patients. This highly powered global effort to identify consistent brain abnormalities showed widespread cortical alterations in MDD patients as compared to controls and suggests that MDD may impact brain structure in a highly dynamic way, with different patterns of alterations at different stages of life.

Epigenetic and Neural Circuitry Landscape of Psychotherapeutic Interventions

The science behind psychotherapy has garnered considerable interest, as objective measures are being developed to map the patient's subjective change over the course of treatment. Prenatal and early life influences have a lasting impact on how genes are expressed and the manner in which neural circuits are consolidated. Transgenerationally transmitted epigenetic markers as well as templates of enhanced thought flexibility versus evasion can be passed down from parent to child. This influences gene expression/repression (impacting neuroplasticity) and kindling of neurocircuitry which can perpetuate maladaptive cognitive processing seen in a number of psychiatric conditions. Importantly, genetic factors and the compounding effects of early life adversity do not inexorably lead to certain fated outcomes. The concepts of vulnerability and resilience are becoming more integrated into the framework of "differential susceptibility," speaking to how corrective environmental factors may promote epigenetic change and reconfigure neural templates, allowing for symptomatic improvement. Psychotherapy is one such factor, and this review will focus on our current knowledge of its epigenetic and neurocircuitry impact.

Effects of cigarette smoking on cortical thickness in major depressive disorder

Findings of surface-based morphometry studies in major depressive disorder (MDD) are still inconsistent. Given that cigarette smoking is highly prevalent in MDD and has documented negative effects on the brain, it is possible that some of the inconsistencies may be partly explained by cigarette use. The aim of the current study was to examine the influence of cigarette smoking on brain structure in MDD. 50 MDD patients (25 smokers and 25 non-smokers) and 22 age, education, gender and BMI matched non-smoker healthy controls underwent structural magnetic resonance imaging. Thickness and area of the cortex were measured using surface-based morphometry implemented with Freesurfer (v5.3.0). The non-smoker MDD patients had significantly increased cortical thickness, including in the left temporal cortex (p < 0.001), right insular cortex (p = 0.033) and left pre- and postcentral gyrus (p = 0.045), compared to healthy controls. We also found decreased cortical thickness in MDD patients who smoked compared to non-smoking patients in regions that overlapped with the regions found to be increased in non-smoking patients in comparison to controls. Non-smoker MDD patients had increased surface area in the right lateral occipital cortex (p = 0.009). We did not find any region where cortical thickness or surface area significantly differed between controls and either smoker MDD patients or all MDD patients. The findings of the current study suggest that cigarette smoking is associated with cortical thinning in regions found to be increased in patients with MDD. However, these results should be considered preliminary due to methodological limitations.

Clinical neuroimaging markers of response to treatment in mood disorders

Mood disorders (MD) are important and frequent psychiatric illness. The management of patients affected by these conditions represents an important factor of disability as well as a significant social and economic burden. The "in-vivo" studies can help researchers to understand the first developmental events of the pathology and to identify the molecular and non-molecular targets of therapies. However, they have strong limitations due to the fact that human brain circuitry can not be reproduced in animal models. In addition, these neural pathways are difficult to be selectively studied with the modern imaging (such as Magnetic Resonance and Positron Emitted Tomography/Computed Tomography) and non-imaging (such as electroencephalography, magnetoencephalography, transcranial magnetic stimulation and evoked potentials) methods. In comparison with other methods, the "in-vivo" imaging investigations have higher temporal and spatial resolution compared to the "in-vivo" non-imaging techniques. All these factors make difficult to fully understand the aetiology and pathophysiology of these disorders, and consequently hinder the analysis of the effects of pharmacological and non-pharmacological therapies, which have been demonstrated effective in clinical settings. In this review, we will focus our attention on the current state of the art of imaging in the assessment of treatment efficacy in MD. We will analyse briefly the actual classification of MD; then we will focus on the "in vivo" imaging methods used in research and clinical activity, the current knowledge about the neural models at the base of MD. Finally the last part of the review will focus on the analysis of the main markers of response to treatment.

GABA+ levels in postmenopausal women with mild-to-moderate depression: A preliminary study

BACKGROUND

It is increasingly being recognized that alterations of the GABAergic system are implicated in the pathophysiology of depression. This study aimed to explore in vivo gamma-aminobutyric acid (GABA) levels in the anterior cingulate cortex/medial prefrontal cortex (ACC/mPFC) and posterior-cingulate cortex (PCC) of postmenopausal women with depression using magnetic resonance spectroscopy (H-MRS).

METHODS

Nineteen postmenopausal women with depression and thirteen healthy controls were enrolled in the study. All subjects underwent H-MRS of the ACC/mPFC and PCC using the "MEGA Point Resolved Spectroscopy Sequence" (MEGA-PRESS) technique. The severity of depression was assessed by 17-item Hamilton Depression Scale (HAMD). Quantification of MRS data was performed using Gannet program. Differences of GABA+ levels from patients and controls were tested using one-way analysis of variance. Spearman correlation coefficients were used to evaluate the linear associations between GABA+ levels and HAMD scores, as well as estrogen levels.

RESULTS

Significantly lower GABA+ levels were detected in the ACC/mPFC of postmenopausal women with depression compared to healthy controls (P = 0.002). No significant correlations were found between 17-HAMD/14-HAMA and GABA+ levels, either in ACC/mPFC (P = 0.486; r = 0.170/P = 0.814; r = -0.058) or PCC (P = 0.887; r = 0.035/ P = 0.987; r = -0.004) in the patients; there is also no significant correlation between GABA+ levels and estrogen levels in patients group (ACC/mPFC: P = 0.629, r = -0.018; PCC: P = 0.861, r = 0.043).

CONCLUSION

Significantly lower GABA+ levels were found in the ACC/mPFC of postmenopausal women with depression, suggesting that the dysfunction of the GABAergic system may also be involved in the pathogenesis of depression in postmenopausal women.

Essential brain structural alterations in major depressive disorder: A voxel-wise meta-analysis on first episode, medication-naive patients

BACKGROUND

Because brain morphological abnormalities in major depressive disorder (MDD) may be modulated by medication and episodes, previous meta-analyses of voxel-based morphometry (VBM) studies therefore have been biased for including medicated patients or medication-free patients who had ever received drugs, as well as patients with different episodes. We sought to identify the essential morphological features without the interference of medication and episodes in MDD.

METHODS

Seed-based d Mapping was applied to analyze the gray matter differences between all first episode (FE), medication-naive MDD patients and healthy controls. Subgroup meta-analyses and meta-regression were used to explore the effects of methodology, demographics and clinical characteristics.

RESULTS

We identified 10 studies comprising 329 FE, medication-naive MDD patients and 340 healthy controls. Gray matter volumes were increased in the bilateral thalamus, cuneus, left paracentral lobule and medial superior frontal gyrus, and decreased in the right dorsolateral superior frontal gyrus, left insula and middle frontal gyrus in patients. Decreased volume in the right inferior temporal gyrus was only observed in patients with short illness duration and studies with threshold corrections. Moreover, there were different results between 3.0T MRI and 1.5T MRI studies. Meta-regression analyses revealed that mean age and the percentage of female patients were not significantly correlated with gray matter changes.

LIMITATIONS

There are heterogeneities in demographics, clinical features and analyzing methods of selected studies.

CONCLUSIONS

The present meta-analysis revealed that structural abnormalities in the fronto-limbic networks are the essential characteristics in MDD and could contribute to the high risk of suicide in patients.

Brain structural connectivity in late-life major depressive disorder

Disrupted brain connectivity might explain both the pathogenesis and consequences of late-life major depressive disorder (LLD). However, it remains difficult to ascertain whether and how specific circuits are affected. We reviewed literature regarding brain connectivity in LLD, and we specifically focused on the role of structural pathology. LLD is associated with greater levels of cerebrovascular disease, and greater levels of cerebrovascular disease are associated with both depression development and treatment responsiveness. Cerebrovascular disease is most often measured as white matter hyperintensity (WMH) burden, and histopathology studies suggest WMH reflect myelin damage and fluid accumulation (among other underlying pathology). WMHs appear as confluent caps around the ventricles (periventricular), as well as isolated lesions in the deep white matter. The underlying tissue damage and implications for brain connectivity may differ by WMH location or severity. WMHs are associated with lower white matter microstructural integrity (measured with diffusion tensor imaging) and altered brain function (measured with functional MRI). LLD is also associated with lower white matter microstructural integrity and grey matter loss which may also alter the network properties and function of the brain. Damage to brain structure reflected by WMH, reduced white matter microstructural integrity, and atrophy may affect brain function, and are therefore likely pathophysiological mechanisms of LLD. Additional research is needed to fully characterize the developmental course and pathology underlying these imaging markers, and to understand how structural damage explains LLD's various clinical manifestations.

The influence of 5-HTTLPR and Val66Met polymorphisms on cortical thickness and volume in limbic and paralimbic regions in depression: a preliminary study

BACKGROUND

Structural brain abnormalities have been investigated in multi-genetic and complex disorders such as major depressive disorder (MDD). Among the various candidate genes implicated in MDD, the brain-derived neurotrophic factor (BDNF) Val66Met polymorphism and 5-HT transporter gene linked polymorphism (5-HTTLPR) have garnered the most attention due to their putative roles in neural plasticity and antidepressant response. However, relatively few studies have assessed the influence of these polymorphysims on cortical thickness or brain volume in para-limbic and limbic regions in MDD, which was the aim of this study.

METHODS

Forty-three adults with MDD and 15 healthy controls (HC) underwent structural magnetic resonance imaging (MRI). Cortical thickness was assessed in frontal, cingulate and temporal regions. Volumetric measures were carried out in the thalamus, caudate, putamen, pallidum, hippocampus and amygdala. Participants were genotyped to determine their 5-HTTLPR (tri-allelic) and Val66Met polymorphisms.

RESULTS

In the combined sample (MDD + HC), smaller right pallidum volumes were found in LA/S (LA/S & LA/LG) heterozygotes compared to S/S (S/S, LG/S & LG/LG) homozygotes, though the effect was modest. In the MDD group, larger left thalamus and putamen volumes were observed in LA/LA homozygotes. No Val66Met or 5-HTTLPR genotype effects existed on cortical thickness and no main effects of the Val66Met polymorphism were observed.

CONCLUSION

Our preliminary results suggest that the 5-HTTLPR polymorphism is associated with morphometric changes in regions known to play an important role in emotional and reward processing in depression. A larger sample size is required to replicate these findings and to potentially reveal subtle morphometric changes.

Cortical thickness and emotion processing in young adults with mild to moderate depression: a preliminary study

BACKGROUND

Major depressive disorder (MDD) is a multifaceted illness involving cognitive, emotional, and structural brain changes; illness onset typically occurs in adolescence or young adulthood. Cortical thickness modulations may underlie, or accompany, functional brain activity changes in the prefrontal cortex (PFC) during emotional processing that tend to be observed in MDD.

METHODS

Thirteen unmedicated young adults with mild to moderate MDD, aged 18-24, completed a facial expression Go/No Go task and underwent a magnetic resonance imaging (MRI) scan to assess cortical thickness. Cortical thickness and performance on the Go/No Go task was also assessed in age-matched healthy comparison subjects (HCs; N = 14).

RESULTS

Participants with depression had thicker left pars opercularis cortices than HCs. They also exhibited impaired response inhibition to neutral faces when responding only to sad faces, and a faster response time overall.

CONCLUSIONS

Though our sample size is limited, this pilot study nevertheless provides evidence for cortical thickening in left frontal brain regions in a non-severely depressed, young adult group compared to healthy controls. There was also evidence of disturbances in emotion processing in this group.

Chronic Depressive Symptomatology in Mild Cognitive Impairment Is Associated with Frontal Atrophy Rate which Hastens Conversion to Alzheimer Dementia

OBJECTIVE

Investigate the association of chronic depressive symptomatology (chrDS) with cortical atrophy rates and conversion to Alzheimer dementia (AD) over 3 years in mild cognitive impairment (MCI).

METHODS

In a multicenter, clinic-based study, MCI elderly participants were selected from the Alzheimer's Disease Neuroimaging Initiative repository, based on availability of both serial structural magnetic resonance imaging and chrDS endorsed on three depression-related items from the Neuropsychiatric Inventory Questionnaire (chrDS N = 32 or no depressive symptoms N = 62) throughout follow-up. Clinical and laboratory investigations were performed every 6 months during the first 2 years and yearly thereafter (median follow-up: 3 years; interquartile range: 1.5-4.0 years). Cortical atrophy rates in 16 predefined frontotemporoparietal regions affected in major depression and AD and the rate of incident AD at follow-up.

RESULTS

ChrDS in a single domain amnestic MCI sample were associated with accelerated cortical atrophy in the frontal lobe and anterior cingulate but not with atrophy rates in temporomedial or other AD-affected regions. During follow-up, 38 participants (42.7%) developed AD. Participants with chrDS had 60% shorter conversion time to AD than those without depressive symptoms. This association remained significant in survival models adjusted for temporomedial atrophy rates and showed the same trend in models adjusted for frontal cortical atrophy rate, which all increased the risk of AD.

CONCLUSION

Our results suggest that chrDS associated with progressive atrophy of frontal regions may represent an additional risk factor for conversion to dementia in MCI as opposite to representing typical prodromal AD symptomatology.

Neuroanatomical correlates of late-life depression and associated cognitive changes

We compared cortical thickness between patients with late-life depression (LLD) and healthy controls and between patients with early-onset (EOD) and late-onset (LOD) depression. We also tested age effects on cortical thickness in LLD and controls and if cortical thickness and hippocampal volumes were associated with cognitive performance in LLD. Three-dimensional T1-weighted magnetic resonance images were obtained in 49 LLD and 49 matched hospital controls and processed using FreeSurfer. General linear model analysis was used as a statistical approach. LLD group had thinning in the left parahippocampal, fusiform, and inferior-parietal cortex compared with controls. Age correlated with cortical thinning in controls but not in LLD. Women in the LOD groups had extensive cortical thinning in the lateral prefrontal cortex bilaterally compared with EOD women. Absence of statistically significant changes observed in men should however be treated with caution because of the low number of men in the study. Mini-Mental Status Examination score correlated with lateral prefrontal cortical thickness bilaterally and hippocampal volume in the total group of LLD and in LOD but not EOD. LLD is associated with cortical thinning, which is associated with age at depression onset, gender, and level of cognitive functioning.

Surface vulnerability of cerebral cortex to major depressive disorder

Major depressive disorder (MDD) is accompanied by atypical brain structure. This study first presents the alterations in the cortical surface of patients with MDD using multidimensional structural patterns that reflect different neurodevelopment. Sixteen first-episode, untreated patients with MDD and 16 matched healthy controls underwent a magnetic resonance imaging (MRI) scan. The cortical maps of thickness, surface area, and gyrification were examined using the surface-based morphometry (SBM) approach. Increase of cortical thickness was observed in the right posterior cingulate region and the parietal cortex involving the bilateral inferior, left superior parietal and right paracentral regions, while decreased thickness was noted in the parietal cortex including bilateral pars opercularis and left precentral region, as well as the left rostral-middle frontal regions in patients with MDD. Likewise, increased or decreased surface area was found in five sub-regions of the cingulate gyrus, parietal and frontal cortices (e.g., bilateral inferior parietal and superior frontal regions). In addition, MDD patients exhibited a significant hypergyrification in the right precentral and supramarginal region. This integrated structural assessment of cortical surface suggests that MDD patients have cortical alterations of the frontal, parietal and cingulate regions, indicating a vulnerability to MDD during earlier neurodevelopmental process.

Cognitive Behavioral Therapies in older adults with depression and cognitive deficits: a systematic review

OBJECTIVES

The objective of this study is to investigate the effectiveness of cognitive behavioral therapies (CBTs) in improving depressive symptoms, disability, and cognition in older adults with depression and cognitive deficits.

DESIGN

It was performed a systematic search for articles published between 1994 and February 2014 in the MEDLINE/Pubmed, PsycINFO, and SCIELO. The studies should have provided information about benefits after CBTs to older adults with depression and cognitive deficits.

RESULTS

Cognitive behavioral therapy focused on problem solving is the main approach studied, having better effectiveness than supportive therapy in randomized clinical trials. Significant improvements in mood and disability were consistent, although evidence of changes in cognitive measures is controversial, less studied, and limited. Nevertheless, improvements in executive functions, processing speed, and changes in patients' perspectives of problem solving skills, such as generating alternatives and decision-making, were described. Also, it would be necessary that future studies more often evaluate cognitive status of depressed elders, as well as cognitive changes after psychotherapy. It should be emphasized that there is a lack of studies in this field, and more approaches in CBTs need to be investigated to this population.

CONCLUSION

Older adults with depression and cognitive deficits can benefit from CBTs. Improvements in mood and disability are more consistent than changes in cognition, which are little studied after CBTs. It is necessary more studies in the field, as well as, to investigate more approaches in CBTs to older adults with depression and cognitive deficits.

Increased involvement of the parahippocampal gyri in a sad mood predicts future depressive symptoms

Behavioral studies suggest a relationship between autobiographical memory, rumination and depression. The objective of this study was to determine whether remitted depressed patients show alterations in connectivity of the posterior cingulate cortex (PCC, a node in the default mode network) with the parahippocampal gyri (PHG, a region associated with autobiographical memory) while intensively recalling negative memories and whether this is related to daily life symptoms and to the further course of depression. Sad mood was induced with keywords of personal negative life events in participants with remitted depression (n = 29) and matched healthy controls (n = 29) during functional magnetic resonance imaging. Additionally, daily life assessments of mood and rumination and a 6-month follow-up were conducted. Remitted depressed participants showed greater connectivity than healthy controls of the PCC with the PHG, which was even stronger in patients with more previous episodes. Furthermore, patients with increased PCC-PHG connectivity showed a sadder mood and more rumination in daily life and a worsening of rumination and depression scores during follow-up. A relationship of negative autobiographical memory processing, rumination, sad mood and depression on a neural level seems likely. The identified increased connectivity probably indicates a 'scar' of recurrent depression and may represent a prognostic factor for future depression.

Structural brain changes associated with depressive symptoms in the elderly with Alzheimer's disease

OBJECTIVE

To examine neuroanatomical changes associated with depressive symptoms in Alzheimer's disease (AD) and the relationship between brain structure and cerebrospinal fluid (CSF) AD biomarkers in depressed and non-depressed patients.

METHODS

Two independent cohorts were used in this study. The first cohort (KI) was collected from the Memory Clinic at Karolinska University Hospital and consisted of 41 AD patients. The second cohort was selected and downloaded from the Alzheimer's Disease Neuroimaging Initiative database (ADNI) and consisted of 148 patient. Patients underwent medical, neuropsychological assessment, laboratory analyses of CSF, including β amyloid 1-42 (Aβ 42), total τ (t-τ), phosphorylated τ 181 (p-τ) and brain MRI examination. In the KI cohort, depression was assessed using the Cornell Scale for Depression in Dementia, and in the ADNI cohort the Geriatric Depression Scale was applied. 3D T1-weighted MRI images were processed using automated steps for segmentation and surface reconstruction implemented in Freesurfer. General linear model analysis was used as a statistical approach.

RESULTS

Cortical thinning in AD patients with depressive symptoms compared with those without was observed in the left parietal and temporal brain regions in both cohorts. Negative correlation between cortical thickness and t-τ was greater in depressed compared with non-depressed AD patients in precuneus and parahippocampal cortex.

CONCLUSIONS

Our findings suggest that depressive symptoms in AD patients are associated with cortical thinning in temporal and parietal regions. In addition, our findings suggest that τ protein pathology in these areas may contribute to the development of depressive symptoms in AD.

Frontal-insula gray matter deficits in first-episode medication-naïve patients with major depressive disorder

OBJECTIVE

This study is designed to investigate the gray matter volume (GMV) deficits in patients with first-episode medication-naïve major depressive disorder (MDD).

METHODS

We enrolled 38 patients with first-episode medication-naïve MDD and 27 controls in this project. Voxel-based morphometry was used to compare GMV differences between two groups. Besides, the relationship between GMV of patients and the severity of clinical symptoms was estimated to confirm the role of GMV deficits in clinical symptoms. The correlation between total GMV and illness duration was also performed to elucidate the impacts of untreated duration on the GMV.

RESULTS

We found that first-episode medication-naïve MDD patients had significant GMV deficits in bilateral superior frontal gyri, left middle frontal gyrus, left medial frontal gyrus and left insula. The GMV of patient group was negatively correlated with the severity of clinical symptoms and the illness duration.

CONCLUSION

A pattern of GMV deficits in fronto-insula might represent the biomarker for first-episode medication-naïve MDD.

Altered local activity and functional connectivity of the anterior cingulate cortex in elderly individuals with subthreshold depression

The anterior cingulate cortex (ACC) is recognized as a key structure in the pathogenesis of depression. This study aimed to investigate the resting-state regional activity and functional connectivity of the ACC in a community sample of elderly individuals with subthreshold depression (StD). We employed resting-state functional magnetic resonance imaging to acquire data from 19 elderly subjects with StD and 18 normal controls. We used a regional amplitude of low-frequency fluctuation (ALFF) analysis and a correlation-based functional connectivity (FC) approach to explore changes in local activity and remote connectivity of the ACC in StD. Compared to controls, the StD group demonstrated increased ALFF in the anterior portion of the dorsal ACC (adACC). The adACC also displayed increased FC with the dorsolateral prefrontal cortex and supplementary motor area and decreased FC with several subcortical regions. The FC levels of the adACC displayed a trending correlation with self-reported depressive symptoms. This study is the first to reveal the ACC changes in resting-state activity and connectivity in the elderly with StD, suggesting that altered ALFF/FC of the adACC is an important feature of StD.

A preliminary study of the influence of age of onset and childhood trauma on cortical thickness in major depressive disorder

BACKGROUND

Major depressive disorder (MDD) neural underpinnings may differ based on onset age and childhood trauma. We assessed cortical thickness in patients who differed in age of MDD onset and examined trauma history influence.

METHODS

Adults with MDD (N=36) and controls (HC; N=18) underwent magnetic resonance imaging. Twenty patients had MDD onset<24 years of age (pediatric onset) and 16 had onset>25 years of age (adult onset). The MDD group was also subdivided into those with (N=12) and without (N=19) physical and/or sexual abuse as assessed by the Childhood Trauma Questionnaire (CTQ). Cortical thickness was analyzed with FreeSurfer software.

RESULTS

Thicker frontal pole and a tendency for thinner transverse temporal cortices existed in MDD. The former was driven by the pediatric onset group and abuse history (independently), particularly in the right frontal pole. Inverse correlations existed between CTQ scores and frontal pole cortex thickness. A similar inverse relation existed with left inferior and right superior parietal cortex thickness. The superior temporal cortex tended to be thinner in pediatric versus adult onset groups with childhood abuse.

CONCLUSIONS

This preliminary work suggests neural differences between pediatric and adult MDD onset. Trauma history also contributes to cytoarchitectural modulation. Thickened frontal pole cortices as a compensatory mechanism in MDD warrant evaluation.

Neuroimaging for psychotherapy research: current trends

OBJECTIVE

This article reviews neuroimaging studies that inform psychotherapy research. An introduction to neuroimaging methods is provided as background for the increasingly sophisticated breadth of methods and findings appearing in psychotherapy research.

METHOD

We compiled and assessed a comprehensive list of neuroimaging studies of psychotherapy outcome, along with selected examples of other types of studies that also are relevant to psychotherapy research. We emphasized magnetic resonance imaging (MRI) since it is the dominant neuroimaging modality in psychological research.

RESULTS

We summarize findings from neuroimaging studies of psychotherapy outcome, including treatment for depression, obsessive compulsive disorder (OCD), and schizophrenia.

CONCLUSIONS

The increasing use of neuroimaging methods in the study of psychotherapy continues to refine our understanding of both outcome and process. We suggest possible directions for future neuroimaging studies in psychotherapy research.