Functional disconnectivity of the hippocampal network and neural correlates of memory impairment in treatment-resistant depression

Ge, Ruiyang; Brown, Jennifer; Gregory, Elizabeth; McLellan, Emily; Downar, Jonathan; Blumberger, Daniel M.; Daskalakis, Zafiris J.; Lam, Raymond W.; Vila‐Rodriguez, Fidel

doi:10.1016/j.jad.2019.04.096

Cited by 41 publications

(16 citation statements)

References 93 publications

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“…In the group of globally impaired patients, however, up to 42% of patients were nonresistant. A possible explanation is that alterations of memory and executive function are more specifically related to treatment resistance (Pimontel et al, 2016;Rao et al, 2019), as observed in C2, in consistence with previous evidence of hippocampus and prefrontal cortex alterations in treatment-resistant depression (Ge et al, 2019). Thus, a global alteration of cognitive function may be reflecting a different phenotype, in which the main characteristic would be cognitive impairment and not exclusively linked to treatment resistancethis may not be unreasonable as the majority of antidepressant treatments do not target cognitive symptoms.…”

Section: Discussionsupporting

confidence: 76%

Dealing with heterogeneity of cognitive dysfunction in acute depression: a clustering approach

et al. 2020

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Background Heterogeneity in cognitive functioning among major depressive disorder (MDD) patients could have been the reason for the small-to-moderate differences reported so far when it is compared to other psychiatric conditions or to healthy controls. Additionally, most of these studies did not take into account clinical and sociodemographic characteristics that could have played a relevant role in cognitive variability. This study aims to identify empirical clusters based on cognitive, clinical and sociodemographic variables in a sample of acute MDD patients. Methods In a sample of 174 patients with an acute depressive episode, a two-step clustering analysis was applied considering potentially relevant cognitive, clinical and sociodemographic variables as indicators for grouping. Results Treatment resistance was the most important factor for clustering, closely followed by cognitive performance. Three empirical subgroups were obtained: cluster 1 was characterized by a sample of non-resistant patients with preserved cognitive functioning (n = 68, 39%); cluster 2 was formed by treatment-resistant patients with selective cognitive deficits (n = 66, 38%) and cluster 3 consisted of resistant (n = 23, 58%) and non-resistant (n = 17, 42%) acute patients with significant deficits in all neurocognitive domains (n = 40, 23%). Conclusions The findings provide evidence upon the existence of cognitive heterogeneity across patients in an acute depressive episode. Therefore, assessing cognition becomes an evident necessity for all patients diagnosed with MDD, and although treatment resistant is associated with greater cognitive dysfunction, non-resistant patients can also show significant cognitive deficits. By targeting not only mood but also cognition, patients are more likely to achieve full recovery and prevent new relapses.

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Section: Discussionsupporting

confidence: 76%

Dealing with heterogeneity of cognitive dysfunction in acute depression: a clustering approach

et al. 2020

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“…Slice timing correction and image realignment to correct head motion were followed. The head motion criteria, that is, head motion <3 mm translation or <3° rotation in any direction, were employed, referring to previous studies (32–34), and all subjects met these criteria. Individual structural images were segmented after co-registered to functional images.…”

Section: Methodsmentioning

confidence: 99%

Inconsistency in Abnormal Functional Connectivity Across Datasets of ADHD-200 in Children With Attention Deficit Hyperactivity Disorder

Zhou

Fang

Lan³

et al. 2019

Front. Psychiatry

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Many studies have shown abnormal functional connectivity in children with attention deficit hyperactivity disorder (ADHD) by using resting-state functional magnetic resonance imaging (rs-fMRI). However, few studies illustrated that to what extent these findings were consistent across different datasets. The present study aimed to assess the consistency of abnormal functional connectivity in children with ADHD across the four datasets from a public-assess rs-fMRI ADHD cohort, namely, ADHD-200. We employed the identical analysis process of previous studies and examined a few factors, including connectivity with the seed regions of the bilateral dorsal anterior cingulate cortex, bilateral inferior frontal gyrus, and bilateral middle frontal gyrus; connectivity between default mode network and executive control network; stringent and lenient statistical thresholds; and the ADHD subtypes. Our results revealed a high inconsistency of abnormal seed-based connectivity in children with ADHD across all datasets, even across three datasets from the same research site. This inconsistency could also be observed with a lenient statistical threshold. Besides, each dataset did not show abnormal connectivity between default mode network and executive control network for ADHD, albeit this abnormal connectivity between networks was intensively reported in previous studies. Importantly, the ADHD combined subtype showed greater consistency than did the inattention subtype. These findings provided methodological insights into the studies on spontaneous brain activity of ADHD, and the ADHD subtypes deserve more attention in future studies.

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“…Sambataro et al ( 2018 ) explored subregional impairment in MDD group and defined subregions by clusters where treatment effect scores correlated with local cortical volume. Ge et al ( 2019 ) explored subregions both in MDD group and health group, and compared parcel size differences between corresponding subregions of two groups. These research studies contributed to a fine‐grained understanding of pathophysiology mechanisms exactly.…”

Section: Introductionmentioning

confidence: 99%

Functional impairment‐based segmentation of anterior cingulate cortex in depression and its relationship with treatment effects

Zhang

Shao

Wang

et al. 2021

Human Brain Mapping

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In major depressive disorder (MDD), the anterior cingulate cortex (ACC) is widely related to depression impairment and antidepressant treatment response. The multiplicity of ACC subdivisions calls for a fine-grained investigation of their functional impairment and recovery profiles. We recorded resting state fMRI signals from 59 MDD patients twice before and after 12-week antidepressant treatment, as well as 59 healthy controls (HCs). With functional connectivity (FC) between each ACC voxel and four regions of interests (bilateral dorsolateral prefrontal cortex [DLPFC] and amygdalae), subdivisions with variable impairment were identified based on groups' dissimilarity values between MDD patients before treatment and HC. The ACC was subdivided into three impairment subdivisions named as MedialACC, Dis-talACC, and LateralACC according to their dominant locations. Furthermore, the impairment pattern and the recovery pattern were measured based on group statistical analyses. DistalACC impaired more on its FC with left DLPFC, whereas Lat-eralACC showed more serious impairment on its FC with bilateral amygdalae. After treatment, FCs between DistalACC and left DLPFC, and between LateralACC and right amygdala were normalized while impaired FC between LateralACC and left amygdala kept dysfunctional. Subsequently, FC between DistalACC and left DLPFC might contribute to clinical outcome prediction. Our approach could provide an insight into how the ACC was impaired in depression and partly restored after antidepressant treatment, from the perspective of the interaction between ACC subregions and critical frontal and subcortical regions.

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Functional disconnectivity of the hippocampal network and neural correlates of memory impairment in treatment-resistant depression

Cited by 41 publications

References 93 publications

Dealing with heterogeneity of cognitive dysfunction in acute depression: a clustering approach

Dealing with heterogeneity of cognitive dysfunction in acute depression: a clustering approach

Inconsistency in Abnormal Functional Connectivity Across Datasets of ADHD-200 in Children With Attention Deficit Hyperactivity Disorder

Functional impairment‐based segmentation of anterior cingulate cortex in depression and its relationship with treatment effects

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