Stressful events and the risk of Alzheimer’s disease

The objective of a new investigation has been to evaluate whether the accumulation of stressful life events throughout life can influence the development of pathologies related to Alzheimer’s disease in later stages.

Stressful life events are those in which objective external threats activate behavioral and psychological responses in us, for example, the death of a loved one, unemployment or illness. There is growing evidence that stress may be associated with an increased risk of dementia and cognitive decline.

The new study is the work of specialists from the Barcelona Institute for Global Health (ISGlobal), a center promoted by the “la Caixa” Foundation, in collaboration with the BBRC (Barcelonaβeta Brain Research Center), a research center of the Pasqual Maragall Foundation.

The research team included 1,290 volunteers from the ALFA cohort of Barcelona, ​​also supported by the “la Caixa” Foundation, all of them without cognitive impairment at the time of the study, but with a direct family history of Alzheimer’s disease.

Participants underwent interviews to assess the number of stressful life events. Likewise, lumbar punctures and magnetic resonance imaging were performed to analyze different biomarkers related to Alzheimer’s disease.

Statistical analyzes revealed that the accumulation of stressful events during midlife was associated with higher levels of β-amyloid protein (Aβ), a key factor in the development of Alzheimer’s disease.

“We know that middle age is a period in which pathologies related to Alzheimer’s disease begin to accumulate. It is possible that these years represent a vulnerable period in which experiencing psychological stress can have a 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 a higher risk of developing neuroinflammation at older ages. Inflammation has been recognized as a key molecular response in neurodegenerative diseases and these results are in line with emerging evidence suggesting that childhood trauma is linked to increased inflammation in adulthood.

Stressful life events are those in which objective external threats activate behavioral and psychological responses in us, for example, the death of a loved one or a severe illness. (Image: Amazings/NCYT)

Sex differences in the impact of stressors

The accumulation of stressful life events throughout life was associated with higher levels of β-amyloid (Aβ) protein only in men. In women, however, the researchers observed that a greater number of stressful experiences throughout life was associated with lower gray matter volumes, implying that stress may have sex-specific effects.

“Our results suggest that the mechanisms through which life stressors affect the brain health of men and women are different: amyloid protein accumulation in men and brain atrophy in women,” says Eider Arenaza-Urquijo. , researcher at ISGlobal and co-author of the study.

Stronger effects in people with a psychiatric history

Finally, the research team found that stressful life events in people with a history of psychiatric illness were associated with higher levels of Aβ and tau proteins, neuroinflammation, and with lower gray matter volume, suggesting that this population may be more susceptible to the effects of stressful life events, for example due to a reduced ability to cope with stress which could make them more vulnerable.

“Our study reinforces the idea that stress could play an important role in the development of Alzheimer’s disease and provides initial evidence on the mechanisms underlying this effect, but additional research is needed to replicate and validate our initial findings,” says Eider Arenaza-Urquijo.

The study is titled “Lifetime Stressful Events Associated with Alzheimer’s Pathologies, Neuroinflammation and Brain Structure in a Risk Enriched Cohort.” And it has been published in the academic journal Annals of Neurology. (Source: ISGlobal)