Can Depression in Midlife Increase Risk of Dementia Later?
3 min. read
Baptist Health Brain & Spine Care
For years, medical professionals have noted a correlation between depression and dementia. However, the nature of that relationship—whether depression causes brain decline or is simply an early warning sign—has remained a subject of intense debate.
A major new 25-year study has shed new light on this connection, identifying specific "minor" mood changes in midlife that may serve as early indicators of dementia risk decades later.
To help navigate these findings, G. Peter Gliebus, M.D., chief of neurology and director of Cognitive and Behavioral Neurology at Marcus Neuroscience Institute, part of Baptist Health, at Boca Raton Regional Hospital, provides his insights in a recent Baptist Health Instagram reel.
The Research: 25 Years of Data
The new study, a longitudinal analysis of data from thousands of participants over more than two decades, didn’t view depression as a single, blanket diagnosis. Instead, it deconstructed the condition into individual symptoms to see which ones were tied to cognitive decline.
"The study demonstrated that the minor changes in the mood can actually predict the future dementia risk," explains Dr. Gliebus. "Researchers followed patients for over 25 years and found that six symptoms, specific symptoms of depression, can be associated with future dementia."
The findings were striking: for adults in their mid-50s, a specific cluster of six symptoms was associated with a significantly increased risk of a dementia diagnosis later in life.
The ‘Six Symptoms’ to Watch
Interestingly, the study found that classic symptoms often associated with clinical depression—such as low mood, sleep disturbances, or suicidal thoughts—did not significantly predict dementia. Instead, the risk was tied to more subtle, personality-driven shifts.
According to Dr. Gliebus: "Those symptoms include loss of confidence, difficulty coping with problems, feeling disconnected from others, persistent nervousness, trouble concentrating, and ongoing dissatisfaction with tasks."
Let’s look closer at these six specific indicators:
- Loss of Confidence: A sudden or gradual decline in self-assurance.
- Difficulty Coping with Problems: An inability to "face up" to daily challenges or feeling overwhelmed by routine decision-making.
- Feeling Disconnected from Others: A lack of warmth or social withdrawal that can reduce "cognitive reserve."
- Persistent Nervousness: Feeling "strung-up" or experiencing a baseline level of anxiety.
- Trouble Concentrating: Problems maintaining focus or mental clarity.
- Ongoing Dissatisfaction with Tasks: A chronic feeling of being unhappy with the way you do things.
Causation vs. Correlation: A Vital Distinction
When discussing these findings, it is easy to assume that depression causes the brain to deteriorate. However, the medical community urges caution with this interpretation.
"This does not mean that depression causes dementia, but the link is still being investigated," Dr. Gliebus notes. Instead of depression acting as the "spark" for dementia, researchers believe these mood shifts may be the "smoke" from a fire already starting in the brain.
In many cases, these six symptoms are likely "prodromal"—meaning they are the very first clinical signs of neurodegeneration. Changes in the brain's chemistry and structure often begin 20 to 30 years before memory loss becomes obvious. These subtle mood shifts may simply be the first way those physical changes manifest.
Why This Matters for Midlife Health
The identification of these symptoms at age 55 provides a critical window for intervention. If these mood changes are early markers, they offer a "heads-up" to patients and doctors to focus on brain health long before traditional cognitive symptoms appear.
By recognizing these symptoms early, individuals can work with their healthcare providers to address modifiable risk factors. While individuals cannot change genetics, they can influence our "cognitive reserve" through social engagement, mental stimulation, and managing physical health factors like blood pressure and hearing loss.
Dr. Gliebus emphasizes the importance of clinical awareness: "So, the new onset depressive symptoms might actually indicate some future changes in the brain, and that needs to be evaluated."
Featured Provider
Gediminas Gliebus, MD
G. Peter Gliebus, M.D., is a board-certified neurologist, chief of neurology and director of cognitive and behavioral neurology at Marcus Neuroscience Institute, a part of Baptist Health. He is fluent in English and Lithuanian.
Dr. Gliebus has a subspecialty certification in behavioral neurology and neuropsychiatry, and specializes in the diagnosis and treatment of conditions and diseases involving the central and peripheral nervous system. His clinical interests include Alzheimer’s disease and other neurodegenerative dementias as well as cognitive problems associated with stroke and similar conditions.
Prior to joining Marcus Neuroscience Institute, Dr. Gliebus served as academic chair of the Department of Neurology at Drexel University College of Medicine, chief of neurology and director of the Alzheimer’s Disease and Cognitive Disorder Center at Crozer Keystone Healthcare System, as well as chair of neurology at Global Neurosciences Institute.
Dr. Gliebus earned his medical degree at the Faculty of Medicine of Vilnius University in Lithuania. He completed a neurology residency at Drexel University College of Medicine, serving as chief resident. He also completed a behavioral neurology and neuropsychiatry fellowship at Northwestern University Feinberg School of Medicine.
For several consecutive years, Dr. Gliebus has been recognized as a Castle Connolly Top Doctor. Physicians receiving this peer-nominated honor are best-in-class healthcare providers, embodying excellence in clinical care as well as interpersonal skills.
Through his years of experience, Dr. Gliebus has developed a comprehensive understanding of the challenges that individuals and their families face when dealing with cognitive disorders. He provides compassionate, personalized care to patients, ensuring accurate diagnosis, effective treatment plans and ongoing support throughout their journey. By staying up to date with the latest advancements in the field, he offers the most comprehensive and innovative approaches to improve the quality of life for individuals with cognitive disorders.
Dr. Gliebus is committed to advancing medical knowledge and finding innovative solutions to complex healthcare challenges. He is the principal investigator for several clinical trials related to memory disorders and dementia. During his involvement in Alzheimer's disease treatment trials, he witnessed firsthand the positive impact that a newly approved medication group had on patients and families.
Dr. Gliebus is credited with more than 60 publications and presentations, is an editorial reviewer for various national specialty journals and editor of the book entitled Progressive Cognitive Impairment and Its Neuropathologic Correlates.
As an educator, Dr. Gliebus shares his wisdom with medical students. He finds that the opportunity to teach and mentor others deepens his knowledge and empowers future generations of healthcare professionals. Dr. Gliebus is a fellow of the American Academy of Neurology and member of the Society for Behavioral and Cognitive Neurology and the Alzheimer’s Association.
He likes to be active during his free time, engaging in physical activities such as running, hiking and other sports. He enjoys exploring new destinations, tasting exotic cuisines and learning about the history and culture of the places he visits. He is also an avid reader, favoring intriguing mysteries and history books.
