Psychosocial factors and hippocampal subfields: The Medea-7T study

Abstract

Specific subfields within the hippocampus have shown vulnerability to chronic stress, highlighting the importance of looking regionally within the hippocampus to understand the role of psychosocial factors in the development of neurodegenerative diseases. A systematic review on psychosocial factors and hippocampal subfield volumes was performed and showed inconsistent results, highlighting the need for future studies to explore this relationship. The current study aimed to explore the association of psychosocial factors with hippocampal (subfield) volumes, using high-field 7T MRI. Data were from the Memory Depression and Aging (Medea)-7T study, which included 333 participants without dementia. Hippocampal subfields were automatically segmented from T2-weighted images using ASHS software. Generalized linear models accounting for correlated outcomes were used to assess the association between subfields (i.e., entorhinal cortex, subiculum, Cornu Ammonis [CA]1, CA2, CA3, dentate gyrus, and tail) and each psychosocial factor (i.e., depressive symptoms, anxiety symptoms, childhood maltreatment, recent stressful life events, and social support), adjusted for age, sex, and intracranial volume. Neither depression nor anxiety was associated with specific hippocampal (subfield) volumes. A trend for lower total hippocampal volume was found in those reporting childhood maltreatment, and a trend for higher total hippocampal volume was found in those who experienced a recent stressful life event. Among subfields, low social support was associated with lower volume in the CA3 (B = -0.43, 95% CI: -0.72; -0.15). This study suggests possible differential effects among hippocampal (subfield) volumes and psychosocial factors.

Keywords: MRI; anxiety; depression; early life adversity; hippocampus; psychosocial.

FIGURE 1

3D segmentation of hippocampal subfields using ASHS on a random participant for visualization, alongside an axial view of a template brain MRI. CA, Cornu ammonis; DG, dentate gyrus; SUB, subiculum; Tail, hippocampal tail; ERC, entorhinal cortex. For segmentation display, please see https://www.nitrc.org/projects/ashs

FIGURE 2

Age‐, sex‐, and intracranial volume‐adjusted means (z‐transformed) for each hippocampal subfield and total hippocampal volume per psychosocial factor. One‐sided standard error bars are shown. p values <.05 are indicated with two asterisks (**), and p values <.001 are indicated with three asterisks (***). CA, Cornu ammonis; DG, dentage gyrus; ERC, entorhinal cortex, HV, hippocampal volume; SUB, subiculum.