Introduction: Several of the brain regions vulnerable to increased levels of stress (i.e., hippocampus and prefrontal cortex) are also known to undergo disproportionate decline during normal aging. To date, surprisingly little research has examined the effects of stress on the brain among healthy human populations, much less in the elderly. The aim of the current study was to investigate the relationship between chronic stress and brain morphometry in regions known for their involvement in the stress response, namely the prefrontal cortex, hippocampus, and amygdala, in a sample of healthy older adults.
Method: The Perceived Stress Scale and structural magnetic resonance imaging (MRI) were collected in 28 older adult individuals aged 65 to 90 years. Gray and white matter volumes in various regions of interest in the prefrontal cortex and medial temporal lobes were calculated using semiautomated segmentation tools.
Results: Perceived stress was negatively correlated with overall prefrontal cortex (PFC) volume, specifically in overall white matter volume of the PFC. Additionally, perceived stress was negatively correlated with gray and white matter volumes in lateral regions of the PFC, specifically, in the ventrolateral and dorsolateral PFC. Perceived stress was not significantly related to medial temporal lobe volumes.
Conclusions: These findings suggest that among healthy older adults, there is a salient relationship between prefrontal cortex volumes and levels of perceived stress. This research fills a critical gap in the current literature and provides initial groundwork for future studies investigating the relationship between perceived stress and the prefrontal cortex in the context of healthy aging.
Keywords: Aging; Brain; Chronic stress; Prefrontal cortex; Stress..