- Researchers followed 67,688 individuals over an average of 25 years to better understand the link between dementia and symptoms of psychological distress (stress, depressed mood, fatigue and anxiety).
- The researchers found that symptoms of psychological distress were associated with an increased risk of dementia.
- A better understanding of dementia risk factors may pave the way for dementia prevention.
Several studies have looked at the association between psychological distress — an umbrella term that includes symptoms of anxiety, depression, and stress — and dementia. However, the relationship between the two is still unclear.
Now, a new study published in
The study was conducted by researchers from the Finnish Institute for Health and Welfare, the University of Helsinki and the University of Eastern Finland.
Previous studies, such as one published in 2022, concluded that individuals with depression levels that were increasingly severe, chronically high, or chronically low, compared with individuals without depression or with a reduction in depressive symptoms. were more likely to develop dementia.
Other studies have found that anxiety, significant exhaustion, and psychological stress are associated with later onset of dementia.
On the other hand, a
Since psychological distress is common in the early stages of dementia, risk-assessment studies must have a sufficiently long interval between the measurement of psychological distress and the incidence of dementia for the results to be reliable.
Studies with an elderly population and short follow-up periods fail to differentiate early (prodromal) symptoms of dementia from causal risk factors.
Another factor that studies on psychological distress and dementia take into account is the competing risk of death. According to some authors, studies should look at whether people with mental health problems have a tendency to
“We could clarify that connection using one of the largest population data sets, long follow-up and careful modeling of mortality.” [from] Other reasons,” explained Dr. Sonja Sulkawa, principal investigator for the study and postdoctoral researcher in Professor Tina Paunio’s group. medical news today,
The study included 67,688 individuals aged 25–74 who participated in the National Finrisk Study survey between 1972 and 2007.
FINRISK was a large Finnish population study on risk factors in chronic, non-communicable diseases conducted for 40 years, and its surveys included questions on symptoms of psychological distress.
Dementia and mortality data for each participant up to 31 December 2017 were obtained from the Finnish Health Register.
“Dr. Sulkawa’s report adds to new evidence that people who have mental health problems in early life have a tendency to develop dementia in later life. This opens a promising window for dementia prevention.”
– Dr. Terry E. Moffitt, Nannerl O. Professor of Psychology at Duke University Kehne and Professor of Social Development at King’s College London, who was not involved in the study
After taking into account the competing risk of death and other factors affecting dementia risk, the researchers found that symptoms of psychological distress were associated with a 17–24% increased risk of dementia in an etiological Poisson model, and 8–12% . Increased incidence of dementia in the Fine-Gray model.
“Our study suggests that symptoms of psychological distress, eg, fatigue, depressed mood and the experience of stress, are risk factors for dementia, not just prodromal symptoms of the underlying dementia disorder. [However], [w]E cannot prove causation.
– Dr. Sonja Sulkawa
Doctor. Moffitt expressed confidence in the findings of this study, noting that the results converge with a
“In 2022, my team also reported that mental health is an early factor in later dementia. We followed 1.7 million New Zealanders in national medical records for 30 years and found that an early-life mental disorder predicted a 4-fold higher risk of later-life dementia,” he said.
Like the Finland population study, the New Zealand study also controlled for competing risk of death.
Associate Professor at the Norwegian University of Science and Technology, Dr. Linda Ernstsen, who was not involved in the study, told mnt,
“The take home message from this study is that mental health issues and a sense of distress are associated with premature death and dementia. These findings highlight the need to focus on mental health at all ages and identify causes and triggers.” represent.”
In their paper, the researchers note that individuals who did not participate in the Finrisk survey or did not have access to information also had more risk factors and an increased risk of dementia and mortality, and that selective participation and non- Responsiveness can skew study results.
The researchers also acknowledged that their measure of psychological distress was not based on a validated multi-item questionnaire, but rather on several single-item measures for different symptoms of psychological distress. However, these measures are significantly correlated and show a consistent pattern of association with dementia.
In addition, the researchers acknowledged that no information was available regarding traumatic brain injury, hearing loss and reduced social interaction – three established risk factors for dementia.
Dr. Sulkawa said study participants were only asked once to report their current symptoms of psychological distress, and this leads to a lack of a “longitudinal perspective” for symptoms.
Dr. Ernstsson pointed out that information on social isolation or marital status was not included. Research has found that being married protects against dementia.
“We also know that cardiovascular disease is associated with both mental health and dementia risk, but it was only the presence of diabetes that was adjusted for in the current study,” Dr Ernstsen said.
Dr. Archana Singh-Manoux, research professor and director at the French Institute of Health and Medical Research (INSERM), who was not involved in the study, said mnt The major limitation of this study is related to the reverse causality.
In one of the models used to calculate dementia risk, when the researchers excluded individuals with less than 10 years of follow-up, a sensitivity analysis showed no significant association between psychological distress and dementia. .
“These findings suggest that the main results of the paper are caused by dementia events occurring immediately after the measure of psychological distress. This is an accurate demonstration of reverse causation, ie psychological distress in the preclinical stage of dementia ‘dementia’ rather than causing psychological distress.
– Dr. Archana Singh-Manoux
When asked about the next phase of the research, Dr. Sulkawa said mnt Larger studies and longer follow-up will be needed.
“Stress, exhaustion, and depressive symptoms are tightly associated with sleep problems, suggesting they are also risk factors for dementia. However, most epidemiological studies lack sufficiently large samples.”[s] Or longer follow-up,” she said.
“Our next step is to study sleep problems and sleep length and dementia risk using a larger Finnish cohort,” he added.