Mid-Life Depression Linked with Dementia Risk

Depression is not a normal part of aging, but several studies have flagged depression in later life as an early symptom of dementia.  Newer research suggests a link between a depression diagnosis in early and mid-life with an increased risk for dementia – highlighting the value of protecting mental health and seeking early treatment for depression. 

According to a recent CNN Health Mindfulness article, a new study, published in the journal JAMA Neurology, suggests that a diagnosis of depression in adulthood could more than double the risk of developing dementia in older age.  Researchers used data from more than 1.4 million Danish citizens between 1977 and 2018.  

Adjusting for education, income, cardiovascular disease, diabetes, substance use disorder and bipolar disorder, researchers found a strong connection between depression in early and mid-life and a higher risk of developing dementia in older age.  The study was limited by the lack of certain data, including genetic information from participants. 

Although the study was able to make a strong connection between depression and dementia, the factors that contribute to this link are not as clear.  Researchers suggest that depression may alter neurotransmitters, increasing the risk for dementia or that depression in earlier life could lead to lifestyle habits and changes in behaviour that contribute to a greater risk for dementia.  More research is needed to clarify the possible mechanisms driving the link between incidences of dementia in later life and earlier-life depression. 

The study also found a stronger association in men than women between depression and dementia risk, leading researchers to consider that women and men may have different factors and mechanisms that influence their risk of developing dementia.  More research is also needed to determine if the timing or duration of depression treatment could lower the risk for later-life dementia.  

The Good News

Early observational studies demonstrate that older adults who participated in therapy that addressed and minimized their symptoms of depression or anxiety had a reduced risk of developing dementia in later life.  Diagnosing and treating depression, at any age, is critical regardless of the dementia risk and patients should be screened for depression regularly by their healthcare provider.  Depression not only influences individual quality of life, but it can also take a toll on loved ones, and contribute to many other physical health problems. 

Learn more about the symptoms of depression and tips for managing depressive disorder by following this link to the Anxiety and Depression Association of America or in Canada follow this link to reach the Centre for Addiction and Mental Health.