- Researchers followed 67,688 people for an average of 25 years to better understand the link between dementia symptoms and psychological distress (stress, depressed mood, exhaustion and tension).
- Symptoms of psychological distress are linked to increased risk of dementia, researchers have found.
- A better understanding of dementia risk factors may pave the way for dementia prevention.
Several studies have looked at the link between psychological distress, an umbrella term that includes symptoms of anxiety, depression, and stress, and dementia. However, the link between the two remains unclear.
Now, an article published in
The study was carried out by researchers from the Finnish Institute of Health and Welfare, the University of Helsinki and the University of Eastern Finland.
Previous research, such as one published in 2022, concluded that people with increasingly severe, chronically high or chronically low levels of depression were less likely to develop dementia than those without depression or with reduced depressive symptoms. more likely.
Other studies have found that anxiety, vital energy and psychological stress are associated with later-onset dementia.
On the other hand, a
Because psychological distress is common in the early stages of dementia, risk determination studies must have a sufficiently long gap between measures of psychological distress and dementia incidence for the results to be considered reliable.
Studies in older populations and short follow-up periods have failed to distinguish early (prodromal) symptoms of dementia from causal risk factors.
Another factor to keep in mind in research on psychological distress and dementia is the competing risk of death.According to some authors, research should take into account whether people with mental health problems tend
“We can clarify this link using one of the largest population datasets, long-term follow-up and careful death modeling [from] other reasons,” the study’s principal investigator and postdoctoral researcher in Professor Tiina Paunio’s group, Dr Sonja Sulkava, told medical news today.
The study included 67,688 people aged 25-74 who participated in the National FINRISK Research Survey between 1972 and 2007.
FINRISK, a 40-year-old large Finnish population study of risk factors for chronic noncommunicable diseases, included questions about symptoms of psychological distress.
Dementia and mortality data for each participant up to 31 December 2017 were obtained from the Finnish Health Register.
“Dr. Sulkava’s report adds to new evidence that people with mental health problems in early life tend to develop dementia later in life. This opens a promising window into dementia prevention.”
— Dr. Terrie E. Moffitt, Nannerl O. Keohane Professor of Psychology at Duke University and Professor of Social Development at King’s College London, who was not involved in the study
Taking into account competing risks of death and other factors influencing dementia risk, the researchers found that symptoms of psychological distress were associated with a 17-24% increased risk of dementia and 8-12% increased dementia risk in a Poisson model of etiology. Increased incidence of dementia in the Fine-Gray model.
“Our research suggests that symptoms of psychological distress, such as exhaustion, depressed mood and stressful experiences, are risk factors for dementia, not just prodromal symptoms of underlying dementia. [However], [w]e Failure to prove causation. “
— Dr. Sonja Sulkava
Dr. Moffitt expressed confidence in the study’s results, noting that the results were consistent with those
“In 2022, my team also reports that mental health is an early factor in later-stage dementia. We followed 1.7 million New Zealanders in national medical records for 30 years and found that early-life mental disorders predicted a 4-fold higher risk of later-life dementia ,”He said,
Like the Finnish population study, the New Zealand study controlled for competing risks of death.
Dr Linda Ernstsen, an associate professor at NTNU who was not involved in the study, told montreal:
“The key message from this study is that mental health problems and distress are associated with premature death and dementia. These findings point to the need to focus on mental health at all ages and identify causes and triggers.”
In their paper, the researchers noted that individuals who did not participate in the FINRISK survey or had missing information also had more risk factors and a higher risk of dementia and death, and that this selective participation and non-response could distort the findings.
The researchers also acknowledged that their measure of psychological distress was not based on a validated multi-item questionnaire, but rather on multiple single-item measures of different symptoms of psychological distress. However, these measures were significantly correlated and showed a consistent pattern of association with dementia.
In addition, the researchers acknowledged that there was no available information on traumatic brain injury, hearing impairment and low social contact — three established risk factors for dementia.
Dr Surkawa added that study participants were only asked once to report their current symptoms of psychological distress, leading to a lack of a “longitudinal perspective” on symptoms.
Information on social isolation or marital status was not included, Dr. Ernstsen noted. Getting married can protect against dementia, study finds.
“We also know that cardiovascular disease is associated with mental health and dementia risk, but this was only adjusted for the presence of diabetes in this study,” added Dr. Ernstsen.
Dr Archana Singh-Manoux, research professor and director of the French Institute for Health and Medical Research (INSERM), who was not involved in the study, told montreal The main limitation of this study has to do with reverse causality.
In one of the models used to calculate dementia risk, a sensitivity analysis showed no significant association between psychological distress and dementia when the researchers excluded individuals who had been followed for less than 10 years.
“These findings suggest that the main results of the paper were due to dementia events that occurred shortly after psychological stress was measured. This is a perfect demonstration of reverse causality, i.e. psychological distress in the preclinical stages of dementia, rather than ‘causing’ dementia psychological distress.”
— Dr. Archana Singh-Manoux
When asked about next steps in research, Dr. Sulkava told montreal Larger studies with longer follow-up are needed.
“Stress, exhaustion, and depressive symptoms are strongly associated with sleep problems, which are also considered risk factors for dementia. However, most epidemiological studies lack sufficiently large samples[s] or long-term follow-up,” she said.
“Our next step is to study sleep problems, sleep duration and dementia risk using a large Finnish cohort,” she added.