Summary: Researchers linked midlife stress and childhood trauma to an increased risk of Alzheimer’s disease and neuroinflammation. Analyzing 1,290 volunteers, researchers found that stressful life events, especially during midlife, correlate with higher levels of β-amyloid protein, crucial in Alzheimer’s development, and that childhood stress is associated with later life neuroinflammation.
Interestingly, the study also uncovered sex-specific effects, with stress leading to amyloid protein accumulation in men and brain atrophy in women. These findings suggest stress’s profound and potentially varied impact on brain health, emphasizing the need for further investigation into its role in neurodegenerative diseases.
Key Facts:
- Stressful life events during midlife and childhood are significantly linked to an increased risk of Alzheimer’s disease and neuroinflammation, respectively.
- The study highlights sex differences in stress’s impact, with men showing higher amyloid buildup and women experiencing greater brain atrophy as a result of stress.
- Individuals with a history of psychiatric disease may be more vulnerable to the adverse effects of stress on brain health, showing higher levels of Alzheimer’s-related proteins and neuroinflammation.
Source: ISGLOBAL
Stressful experiences in midlife or during childhood may be associated with a higher risk of developing Alzheimer’s disease and neuroinflammation, respectively.
This is one of the conclusions of a study published in Annals of Neurology and led by the Barcelona Institute for Global Health (ISGlobal), a centre supported by the “la Caixa” Foundation, in collaboration with the Barcelonaβeta Brain Research Center (BBRC), research centre of the Pasqual Maragall Foundation.
Stressful Life Events are those in which objective external threats activate behavioural and psychological responses on us, for example, death of a loved one, unemployment or illness. Mounting evidence suggests that stress could be associated with an increased risk of dementia and cognitive decline.
The purpose of this research was to assess whether the accumulation of stressful life events throughout life could influence the development of Alzheimer’s-related pathologies in older ages.
To do so, the research team counted on 1,290 volunteers from the ALFA cohort in Barcelona, also supported by the ”la Caixa” Foundation, all of them cognitively unimpaired at the time of the study, but with a direct family history of Alzheimer’s disease.
Participants went through interviews to assess the number of Stressful Life Events. Lumbar punctures and magnetic resonance imaging (MRI) were performed to test different biomarkers related to Alzheimer’s disease.
Midlife as a vulnerable period
The statistical analyses revealed that the accumulation of stressful events during midlife was associated with higher levels of β-amyloid (Aβ) protein, a key player in the development of Alzheimer’s disease.
“We know midlife is a period when Alzheimer’s disease pathologies start to build up. It is possible that these years represent a vulnerable period where experiencing psychological stress may have a long-lasting impact on brain health”, says Eleni Palpatzis, ISGlobal researcher and first author of the study.
Childhood stress and neuroinflammation
The research team also found that higher levels of stressful experiences in childhood were associated with higher risk of developing neuroinflammation in older ages.
Inflammation has been recognized as a key molecular response in neurodegenerative diseases and these results are in line with emerging evidence suggesting childhood trauma to be linked with increased adulthood inflammation.
Sex differences on the impact of stressors
Accumulation of stressful life events over the course of life was associated with higher levels of β-amyloid (Aβ) protein only in men. In women, however, the researchers observed that more stressful experiences over the course of life were associated with lower volumes of grey matter, implying that stress may have sex-specific effects.
“Our results suggest that the mechanisms through which life stressors affect brain health in men and women are different: amyloid protein accumulation in men and brain atrophy in women”, says Eider Arenaza-Urquijo, ISGlobal researcher and last author of the study.
Stronger effects in people with psychiatric history
Lastly, the authors found that stressful life events in people with a history of psychiatric disease were associated with higher levels of Aβ and tau proteins, neuroinflammation and with lower grey matter volume, suggesting that this population could be more susceptible to the effects of stressful life events, for example, due to impaired stress-coping abilities which could make them more vulnerable.
“Our study reinforces the idea that stress could play a significant role in the development of Alzheimer’s disease and provides initial evidence regarding the mechanisms behind this effect, but additional research is needed to replicate and validate our initial findings”, says Eider Arenaza-Urquijo.
About this mental health and Alzheimer’s disease research news
Author: Pau Rubio
Source: ISGLOBAL
Contact: Pau Rubio – ISGLOBAL
Image: The image is credited to Neuroscience News
Original Research: Open access.
“Lifetime Stressful Events Associated with Alzheimer’s Pathologies, Neuroinflammation and Brain Structure in a Risk Enriched Cohort” by Eider Arenaza-Urquijo et al. Annals of Neurology
Abstract
Lifetime Stressful Events Associated with Alzheimer’s Pathologies, Neuroinflammation and Brain Structure in a Risk Enriched Cohort
Objective
Along with the known effects of stress on brain structure and inflammatory processes, increasing evidence suggest a role of chronic stress in the pathogenesis of Alzheimer’s disease (AD). We investigated the association of accumulated stressful life events (SLEs) with AD pathologies, neuroinflammation, and gray matter (GM) volume among cognitively unimpaired (CU) individuals at heightened risk of AD.
Methods
This cross-sectional cohort study included 1,290 CU participants (aged 48–77) from the ALFA cohort with SLE, lumbar puncture (n = 393), and/or structural magnetic resonance imaging (n = 1,234) assessments. Using multiple regression analyses, we examined the associations of total SLEs with cerebrospinal fluid (1) phosphorylated (p)-tau181 and Aβ1–42/1–40 ratio, (2) interleukin 6 (IL-6), and (3) GM volumes voxel-wise. Further, we performed stratified and interaction analyses with sex, history of psychiatric disease, and evaluated SLEs during specific life periods.
Results
Within the whole sample, only childhood and midlife SLEs, but not total SLEs, were associated with AD pathophysiology and neuroinflammation. Among those with a history of psychiatric disease SLEs were associated with higher p-tau181 and IL-6. Participants with history of psychiatric disease and men, showed lower Aβ1–42/1–40 with higher SLEs. Participants with history of psychiatric disease and women showed reduced GM volumes in somatic regions and prefrontal and limbic regions, respectively.
Interpretation
We did not find evidence supporting the association of total SLEs with AD, neuroinflammation, and atrophy pathways. Instead, the associations appear to be contingent on events occurring during early and midlife, sex and history of psychiatric disease.
