Stressful childhood experiences accelerate brain ageing

Severe stress and trauma 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. Researchers at Charité – Universitätsmedizin Berlin have demonstrated that severe early-life adversity is linked to measurable markers of accelerated brain ageing and amplifies neurodegenerative processes later in life. The study, which focuses on women, is published in the Annals of Neurology.

Prof Christine Heim, the study’s principal investigator said around 30% to 40% of the population report highly stressful or traumatic childhood experiences – including abuse, neglect, domestic violence, substance abuse or criminality in the family, or the loss of a parent. ‘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,’ she said.

Prof Heim’s research team 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 (MRI) to record the size of participants’ brains and the cavities filled with cerebrospinal fluid. They also measured participants’ cognitive function using a standardised, internationally recognized 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,’ explains Fleck.

The researchers analyzed 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.

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 aging in women. It appears that stressful experiences early in life indeed increase the risk of developing neurodegenerative disorders,’ adds Prof. 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.’
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.

In future research, Prof. Heim and her team hope to examine whether similar correlations exist among men. ‘The research results we’ve produced to date relate solely to women,’ says Prof. Heim. ‘They do not allow us to conclude, however, that women with stressful early-life experiences are at greater risk than men.’