Summary: Depressive symptoms and memory decline in older adults are closely linked, with each influencing the other. Using 16 years of data from 8,268 adults, researchers found that depression can precede memory decline and that poor memory can lead to increased depressive symptoms.
This bidirectional relationship suggests that treating one condition can help alleviate the other. The results highlight the importance of monitoring and intervening for depression and memory problems in older adults.
Highlights:
- Depressive symptoms may precede and predict memory decline in older adults.
- Poor memory can lead to increased depressive symptoms over time.
- Interventions targeting depression can help slow memory decline and vice versa.
Source: UCL
Depressive symptoms are linked to later memory decline in older people, while poorer memory is also linked to later increases in depressive symptoms, according to a new study led by UCL and Faculty researchers of Medicine of Brighton and Sussex.
The study, published in Open JAMA Networkexamined 16 years of longitudinal data from 8,268 adults in England with a mean age of 64 years.
The researchers concluded that depression and memory were closely linked, with the two appearing to influence each other.
Lead author Dr Dorina Cadar, from UCL’s Department of Behavioral and Health Sciences and Brighton and Sussex Medical School, said: “Depression and poor memory are known to commonly occur together in older adults, but which comes first is unclear.
“Our study shows that the relationship between depression and poor memory goes both ways, with depressive symptoms preceding memory decline and memory decline being linked to later depressive symptoms.
“It also suggests that interventions aimed at reducing depressive symptoms could help slow memory decline.”
Lead author Jiamin Yin, a UCL graduate and now a PhD student at the University of Rochester, New York, said: “These findings highlight the importance of monitoring memory changes in older people with increasing depressive symptoms. to identify memory loss early and prevent further worsening of depressive function.
“Conversely, it is also essential to address depressive symptoms in people with memory decline to protect them from developing depression and memory dysfunction. »
The research team suggested that depression might affect memory due to depression-related brain changes. These include neurochemical imbalances (e.g. lower levels of serotonin and dopamine), structural changes in regions involved in memory processing, and disruptions in the brain’s ability to reorganize and form new connections.
The team said memory problems could also result from psychological factors such as rumination, that is, repetitive thinking or dwelling on negative feelings.
On the other hand, people experiencing memory loss or difficulty retaining new information may experience frustration, loss of confidence, and feelings of incompetence, which are common triggers for depressive episodes.
Memory problems can also disrupt daily functioning and social interactions, leading to social isolation that can trigger depressive symptoms.
Dr Cadar added: “Depression can cause changes in brain structures, such as the hippocampus, which is essential for memory formation and retrieval. Chronic stress and high cortisol levels associated with depression can damage neurons in these areas.
“However, a better understanding of the mechanisms linking memory decline and depression is crucial for developing targeted interventions aimed at improving mood and slowing cognitive decline in people with depression and memory impairment. »
For this study, researchers looked at data from the English Longitudinal Study of Aging (ELSA), in which a nationally representative population sample in England answers a wide range of questions every two years.
People who started with higher depressive symptoms were more likely to experience a faster decline in memory later, while those who started with lower memory were more likely to experience a later increase in depressive symptoms.
Additionally, participants who experienced a greater increase in their depressive symptoms over the course of the study were more likely to have a greater memory decline at the same time, and vice versa – those who had a greater memory decline pronounced were more likely to have a greater increase in their depressive symptoms. depressive symptoms.
The same trend was not found for verbal fluency. Although less verbal fluency was linked to more depressive symptoms at the start of the study, changes in one did not predict later changes in the other.
The researchers took into account a range of factors that may have affected the results, such as physical activity and life-limiting illnesses. As an observational study, the researchers noted, it could not establish causality.
Funding: The study and its authors received support from the National Institute on Aging, the Economic and Social Research Council (ESRC), the National Institute for Health and Research (NIHR), Alzheimer’s Society UK and Alzheimer’s Research UK.
About this research news on depression and cognitive decline
Author: Mark Greaves
Source: UCL
Contact: Mark Greaves – UCL
Picture: Image is credited to Neuroscience News
Original research: Free access.
“Bidirectional relationship between depressive symptoms and cognitive function over time” by Dorina Cadar et al. Open JAMA Network
Abstract
Bidirectional relationship between depressive symptoms and cognitive function over time
Importance
Cognitive decline and depressive symptoms often coexist in older adults and share several mechanisms. Despite the fact that cognitive dysfunction has been associated with increased depressive symptoms, the direction of this association remains unclear.
Objective
To examine whether there is a bidirectional association between depressive symptoms and cognitive function in English adults aged 50 years or older across a 16-year follow-up period.
Design, setting and participants
This cohort study included a nationally representative sample of community-dwelling English adults aged 50 years or older. The current analysis included 8,268 eligible participants with relevant data.
These participants were examined every two years from 2002 and 2003 until 2018 and 2019, resulting in a follow-up period of up to 16 years. Data was analyzed from July to November 2023.
Main results and measures
Bivariate dual change score models were used to estimate multivariable associations between depressive symptoms and cognitive function, which were used interchangeably as exposures and outcomes. Cognitive measures include tests of memory and verbal fluency, while the Center for Epidemiologic Studies Depression Scale assessed depressive symptoms.
Results
The study population, consisting of 8,268 participants, had a mean (SD) age of 64 (10) years at study baseline, and 4,517 participants (55%) were female. Higher depressive symptoms were cross-sectionally associated with poorer memory (β intercept, −0.018; standard error (SE), 0.004; P.< 0.001) and verbal fluency (intercept β, −0.009; SE, 0.004; P.= 0.02) at the start of the study.
A more pronounced linear change in depressive symptoms was associated with accelerated memory change (intercept β, −0.253; SE, 0.079; P.= 0.001), and a linear change in memory was associated with an acceleration of depressive symptoms over time (intercept β, 0.016; SE, 0.006; P.= 0.005). This bidirectional change was not observed with verbal fluency.
Conclusions and relevance
In this study, greater depressive symptoms were associated with poorer memory at baseline and greater memory changes over time. A progressive linear change in depressive symptoms contributed to accelerated memory loss and vice versa, suggesting that psychological mood and memory performance are intrinsically associated.