Healthcare (Commonwealth Union) – A new study led by researchers at University College London has found that certain depressive symptoms experienced during midlife are linked to a higher risk of developing dementia more than 20 years later. Rather than depression as a general condition, the research highlights the importance of specific emotional and cognitive experiences in shaping long-term brain health.
While depression in midlife has long been viewed as a risk factor for dementia in older age, findings published in The Lancet Psychiatry suggest this connection is not uniform. Instead, the increased risk appears to be driven by a small set of particular symptoms, including a loss of self-confidence, difficulty coping with problems, reduced feelings of warmth or affection toward others, persistent nervousness or tension, dissatisfaction with how tasks are completed, and problems with concentration.
According to the researchers, identifying and addressing these six symptoms in people experiencing depression during midlife could potentially help lower their chances of developing dementia later on. However, they emphasise that further studies are needed to better understand how and why these symptoms influence long-term cognitive decline.
Dr Philipp Frank from UCL’s Division of Psychiatry, the study’s lead author, indicated that the results point to a more precise way of assessing dementia risk. He noted that focusing on individual depressive symptoms, rather than depression as a single broad diagnosis, offers clearer insight into who may be more vulnerable many years before dementia symptoms emerge.
Dr Frank further indicated that symptoms faced by many people daily that they experience in midlife appear to have significant information in regards to long-term brain health. He indicated that focusing on these patterns could create a new pathway for early prevention.
The study examined information from 5,811 adults in midlife who were part of the Whitehall II study, a long-running UK research project launched in 1985 with funding from the Medical Research Council and Wellcome.
Symptoms of depression were measured between 1997 and 1999, at a time when all participants were free of dementia and aged between 45 and 69, with an average age of 55. A survey assessing 30 commonly reported depressive symptoms was used. Researchers then followed participants’ health outcomes for the next 25 years using national health records, tracking dementia diagnoses through to 2023. Over the course of the follow-up, 10.1% of the group went on to develop dementia. The lengthy observation period enabled the team to explore links between early-life symptoms and dementia risk long before typical signs of neurodegeneration appear.
Results showed that individuals who met the criteria for depression in midlife—defined as reporting at least five symptoms—had a 27% higher likelihood of developing dementia later in life. However, this elevated risk was fully explained by six particular symptoms among participants younger than 60. Notably, reduced self-confidence and an inability to deal with problems were each linked to about a 50% higher risk of dementia.
The authors explain that signs such as reduced self-belief, struggling to deal with challenges, and trouble focusing may result in people withdrawing socially and engaging less in mentally stimulating activities. Both factors are known to support cognitive reserve — the brain’s capacity to withstand injury or illness and continue normal thinking and functioning even when physical changes occur.
By comparison, other features of depression, such as sleep disturbances, thoughts of suicide, or persistently low mood, were not found to have a significant long-term link with the development of dementia.
Professor Mika Kivimäki (UCL Faculty of Brain Sciences), who leads the Whitehall II study and co-authored the paper, says “Depression doesn’t have a single shape — symptoms vary widely and often overlap with anxiety. We found that these nuanced patterns can reveal who is at higher risk of developing neurological disorders. This brings us closer to more personalised and effective mental health treatments.”
