Research has demonstrated that severe early-life adversity is linked to measurable markers of accelerated brain ageing and can amplify neurodegenerative processes later in life.
Stressful or traumatic experiences in childhood have been shown to negatively impact an individual’s health as an adult.
Those affected face an increased risk of illness and often suffer from depression, anxiety disorders, and cardiovascular or metabolic diseases. Until now, little has been known about whether such experiences could contribute to the development of neurodegenerative diseases.
“Stress and trauma during childhood, such as abuse, neglect, domestic violence, substance abuse or criminality in the family, or the loss of a parent – in fact, these experiences affect a considerable number of individuals in our society,” said professor Christine Heim, principal study investigator and director of the Institute of Medical Psychology at Charité – Universitätsmedizin Berlin.
“Around 30 per cent to 40 per cent of the population report highly stressful or traumatic childhood experiences. Such experiences can leave molecular and neurobiological traces and influence the endocrine and immune systems, which can contribute to lifelong elevated risk of developing various diseases.”
In their investigation, Heim’s research team sought to determine whether these adverse early-life experiences have a long-term impact on brain ageing and contribute to neurodegenerative processes.
The study, conducted in close collaboration with the Department of Neurology at Charité, examined 179 female participants between 30 and 60 years old.
Women have a higher risk of developing neurodegenerative diseases, so the researchers decided to focus their attention on this high-risk group.
“We started by conducting clinical interviews to ascertain the degree to which the participants had highly stressful or troubling experiences in childhood – before the onset of puberty,” says Lara Fleck, a doctoral candidate at the Institute of Medical Psychology at Charité and the paper’s lead author.
“We also examined blood samples from the participants with high-precision technologies, looking for biomarkers that indicate specific neuroinflammatory processes and nerve cell damage.”
The researchers used magnetic resonance imaging to record the size of participants’ brains and the cavities filled with cerebrospinal fluid. They also measured participants’ cognitive function using a standardised, internationally recognised assessment.
“The participants were required to complete different computer-based tasks. For our study, we selected three specific tests that can detect early signs of dementia with high precision,” said Fleck.
The researchers analyded the collected data with the help of statistical models. They accounted for socioeconomic factors and psychiatric symptoms such as depression, which can also play a role in the development of neurodegenerative diseases, to avoid confounding of the effects of early-life stress reported in the study.
Early-life stress contributes to intensified brain ageing
The results across all three levels of investigation were conclusive: women who experienced significant stress or trauma in childhood had higher levels of biomarkers of neuroinflammation and neurodegeneration in their blood, had a lower brain volume and displayed more cognitive problems.
“Our study’s results demonstrate a very clear link between early-life experiences of psychosocial or socio-emotional stress and accelerated brain ageing in women. It appears that stressful experiences early in life indeed increase the risk of developing neurodegenerative disorders,” added Heim.
“Further investigation is now required to shed light on the underlying mechanisms, so that suitable treatments can be devised to interrupt disease pathways in a targeted manner and at an early stage.”
“We need to gain a deeper understanding regarding risk factors that play a role in the development of neurodegenerative diseases, especially given the marked increase in conditions such as Alzheimer’s,” says professor Matthias Endres, director of the Department of Neurology at Charité.
“Our findings shed light on previously unknown connections – which makes them all the more important.”
However, not everyone who experiences childhood trauma goes on to develop dementia. Many individuals demonstrate remarkable resilience, allowing them to withstand severe crises without suffering long-term harm.
Targeted means of fostering resilience following stressful early-life experiences is a key topic for future studies, the researchers say.