Hippocampal volume in vulnerability and resilience to depression

J Affect Disord. 2016 Jan 1;189:199-202. doi: 10.1016/j.jad.2015.09.021. Epub 2015 Oct 1.

Abstract

Background: Reduced hippocampal volume has been associated with clinical depression. However, it remains unclear whether these changes are a biological vulnerability marker or a consequence of this disorder. METHODS AND RESULTS (STUDY 1): We first compared hippocampal volumes between (i) never-depressed individuals with elevated risk for depression by virtue of high neuroticism (ii) recovered depressed individuals with matched levels of neuroticism; and (iii) individuals with low neuroticism and no history of depression. We replicated the finding of reduced hippocampal volume in the recovered group; unexpectedly however, the never-depressed high-risk group showed an increase in volume. One hypothesis is that this group had a mean age above the typical onset age for depression; hence, these participants who have remained euthymic despite their personality risk might in fact possess some resilience. METHODS AND RESULTS (STUDY 2): A subsequent study was therefore carried out to compare hippocampal volume between high-neurotic vs. low-neurotic volunteers in a younger sample. No group difference was found.

Limitations: The present findings are limited by a small sample size; the cross-sectional design precluded us from makineg definitive conclusions about causal effect.

Conclusion: Our overall results suggest that reduced hippocampal volumes is a neural marker for the scar effect of depression, although this structural impairment could also be seen as a vulnerability marker for the development of future recurrent episodes. By contrast, larger hippocampal volumes could be a biological marker of resilience. These findings have clinical implications regarding treatment development for the prevention of illness onset and recurrent depressive episodes.

Keywords: Depression; Hippocampus; Neuroticism; Resilience; Risk; Vulnerability.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Anxiety Disorders / complications
  • Anxiety Disorders / pathology
  • Atrophy / pathology
  • Case-Control Studies
  • Cross-Sectional Studies
  • Depression / complications
  • Depression / pathology*
  • Female
  • Hippocampus / pathology*
  • Humans
  • Hypertrophy / pathology
  • Magnetic Resonance Imaging
  • Male
  • Middle Aged
  • Neuroimaging
  • Neuroticism
  • Resilience, Psychological*
  • Risk Factors
  • Young Adult