Amygdala Functional Connectivity Features in Grief: A Pilot Longitudinal Study

Abstract

Objective.-Acute grief, in an important minority of older adults, can become protracted, intense, and debilitating, leading to the development of complicated grief (CG). However, the neurobiological mechanisms underlying a maladaptive grief response after an attachment loss are unknown. The current study aimed to examine the amygdala brain network features that crosssectionally explain the symptom variance and longitudinally relate to grief symptom trajectories after an attachment loss.Methods.-Baseline amygdala functional connectivity (Fc) was assessed using a seed-based resting-state functional MRI method in 35 adults who were within one-year after death of a loved one and 21 healthy comparison (HC) participants. MRI scans were obtained at baseline, and clinical assessments, including the inventory of complicated grief (ICG) were completed at weeks 0, 8, 16, and 26 (endpoint).Results.-Relative to HC participants, grief participants showed increased amygdala Fc in the posterior default mode (bilateral medial temporal lobes and left precuneus) and thalamus. Amygdala Fc in the default mode and ventral affective regions positively correlated with ICG scores at baseline. Furthermore, increased baseline amygdala functional connections with the dorsal frontal executive control and salience network regions correlated with worsening ICG scores over time. These longitudinal findings persisted after controlling for covariates, including baseline depressive and anxiety symptoms.

Abnormal Functional Connectivity of the Amygdala in Mild Cognitive Impairment Patients With Depression Symptoms Revealed by Resting-State fMRI

“…Their results showed that MCI reduced the positive amygdala FC with parieto-occipital regions, insula, and hippocampus; mild AD patients reduced the amygdala FC mainly in the medial temporal and insular regions (55). These studies show that the severity of symptoms is the result of multiple neural network changes, not necessarily parallel to a single network change (56)(57)(58). This may be one of the reasons why we did not find a correlation between the amygdala-FC and neuropsychological performance.…”

Early Adversity and Emotion Processing From Faces: A Meta-analysis on Behavioral and Neurophysiological Responses

“…There is evidence that amygdala responses to sad stimuli are higher without cognitive reappraisal and involvement of the dorsolateral prefrontal cortex (59). In addition, individuals with complicated or recent grief have elevated amygdala reactivity to sadness (60) and stronger connections between the amygdala and regions involved in autobiographic memory (61).…”

Dwelling in prolonged grief: Resting state functional connectivity during oxytocin and placebo administration

“…In a recent longitudinal study, bereaved adults who displayed greater amygdala functional connectivity with salience and executive control networks experienced worsening grief symptoms over time. Cross‐sectionally, higher prolonged grief symptoms were associated with greater amygdala functional connectivity with posterior default network regions (Chen et al, 2020 ). Further, treatment‐seeking bereaved adults who received 8 weeks of mindfulness‐based cognitive therapy showed decreased resting state functional connectivity between salience, default, and executive control networks (Huang et al, 2021 ).…”