Depression, hippocampal volume changes, and cognitive decline in a clinical sample of older depressed outpatients and non-depressed controls

Abstract

Objective The aim of this study was to develop and test a model of depression, hippocampal changes, and cognitive decline. Method Participants were 248 community-dwelling, depressed patients and 147 healthy, non-depressed individuals 60 years and older. Participants received a structured interview assessing current depressive symptoms and past depressive episodes, completed cognitive testing with the MMSE, and underwent structural MRI of the brain. For up to ten years, assessment of depressive symptoms and MMSE administration was repeated at least annually, and MRI was repeated every two years. Results Regression analyses demonstrated that depression diagnosis at baseline predicted decrease in right (but not left) hippocampal volume over a four-year period. Analyses using structural equation modeling demonstrated that a decrease in left and right hippocampal volume predicted decrease in MMSE score over four years. Conclusion Results provide some evidence for relationships between depression and decrease in right hippocampal volume, and between hippocampal volume and MMSE score. This would be consistent with depression as a causal factor in subsequent cognitive decline. Plausible biological mechanisms include a glucocorticoid cascade or a facilitating effect of depression on amyloid-beta plaque formation. Future studies should examine the relationship between hippocampal volume and specialized memory measures, as well as between depression diagnosis and volume of other brain structures.

Adult Neurogenesis and Psychiatric Disorders

“…Meta-analyses from numerous MRI studies have since confirmed this observation (Videbech and Ravnkilde 2004;Geuze et al 2005;McKinnon et al 2009). This same correlation holds true even for late-onset depression (Sawyer et al 2012;Sexton et al 2012). Postmortem observations have also confirmed similar reductions in hippocampal volume (Rajkowska et al 1999), but it is not yet known whether a decrease in adult neurogenesis is a contributing factor and to what extent.…”

Gender differences in the longitudinal associations of depressive symptoms and leisure-time physical activity with cognitive decline in ≥57year-old Taiwanese

“…A meta-analysis showed that patients with depression had a smaller hippocampal volume than healthy people (Videbech and Ravnkilde, 2004). A decrease in hippocampal volume predicted lower scores in cognitive tests over a four-year period (Sawyer et al, 2012). Long-term depressive symptoms may further decrease the volume of hippocampus and increase the risk of developing cognitive decline.…”

Wnt signaling in neuropsychiatric disorders: Ties with adult hippocampal neurogenesis and behavior

“…For instance, post-mortem studies and imaging techniques such as MRI have shown an associated hippocampal atrophy or loss in hippocampal volume in depressed patients (MacQueen et al, 2008; Maller et al, 2007; Malykhin et al, 2010; Neumeister et al, 2005; Sawyer et al, 2012). In one human study of depression, use of selective serotonin reuptake inhibitors (SSRIs) and tricyclic and tetracyclic antidepressants (TCAs) was correlated with an increase in overall dentate gyrus volume and also increased neural progenitor cells in the anterior hippocampus (Boldrini et al, 2009).…”