December 24, 2025
Being depressed has been linked to an increased risk of developing Alzheimer’s disease and other forms of dementia. Now researchers have identified six specific symptoms of depression in midlife that may be particularly strong risk factors for dementia in old age.
The six depressive symptoms that should raise particular concern are:
- Losing confidence in oneself
- Not being able to face up to problems
- Not feeling warmth and affection for others
- Feeling nervous and worried all the time
- Not feeling satisfied with the ability to carry out tasks or solve problems
- Having difficulties concentrating
Focusing on these six symptoms when treating patients with depression in midlife, the researchers say, may reduce their risk of getting Alzheimer’s disease or other forms of dementia later in life, though more study is needed to better understand the links between depression and dementia.
“Our findings show that dementia risk is linked to a handful of depressive symptoms rather than depression as a whole,” said Philipp Frank, the study’s lead author and a senior research fellow in University College London’s Division of Psychiatry. “This symptom-level approach gives us a much clearer picture of who may be more vulnerable decades before dementia develops.” The results were published in The Lancet Psychiatry.
Dr. Frank continued: “Everyday symptoms that many people experience in midlife appear to carry important information about long-term brain health. Paying attention to these patterns could open new opportunities for early prevention.”
For the study, the researchers analyzed data from 5,811 middle-aged men and women who were part of the Whitehall II study, a long-running British health study that began in 1985. Participants were screened for depression during midlife, at an average age of 55, using a detailed questionnaire that covered 30 common symptoms of depression. None had dementia at the start of the study.
The researchers followed them for more than two decades. During this time, about 10 percent developed Alzheimer’s disease or another form of dementia.
The researchers found that overall, those who were classified as having depression in midlife had a 27 percent higher risk of developing dementia late in life. This increased risk, however, appeared to be driven by the six specific symptoms listed earlier. Loss of self-confidence and difficulty coping with problems, for example, were each associated with about a 50 percent increased risk of dementia.
Such symptoms, the researchers say, often lead people to become socially isolated and to withdraw from cognitively stimulating activities. Lack of social or mental stimulation, in turn, may make the brain more susceptible to the ravages of a disease like Alzheimer’s.
Other symptoms of depression in midlife, such as sleep troubles, feeling suicidal, or feeling sad, were not linked to an increased risk of dementia later in life.
The authors note that there is some limited evidence that treating depression in midlife might reduce later dementia risk, but that further research is needed to better understand the links between depression and dementia. They also caution that it’s important to note that not everyone who has depression will go on to develop dementia, and that people with dementia won’t necessarily develop depression. While the findings of this study show a correlation, they do not show cause and effect.
Symptoms of depression are many and varied and often overlap. In addition to the symptoms noted, they can include feeling sad, apathetic, guilty, worthless or hopeless for weeks to months on end; loss of interest in daily activities, especially ones that used to bring pleasure; poor appetite and weight loss, or increased appetite and excessive weight gain; feeling anxious or agitated and irritable; and focusing on non-serious physical complaints.
If you experience one or more of these symptoms, or other unusual changes in mood or behavior, consult your doctor. Medications and therapeutic counseling are available that can provide relief.
By ALZinfo.org, The Alzheimer’s Information Site. Reviewed by Eric Schmidt, Ph.D., Fisher Center for Alzheimer’s Research Foundation at The Rockefeller University.
Source: Philipp Frank, PhD; Archana Singh-Manoux, PhD; Jaana Pentti, BSc; et al: “Specific midlife depressive symptoms and long-term dementia risk: a 23-year UK prospective cohort study.” The Lancet Psychiatry, December 15, 2025
