People with Depression or Anxiety May Develop Alzheimer’s at Younger Ages

March 9, 2021

Depression and anxiety are tied to earlier onset of Alzheimer’s disease, according to a new report. The study found that people with depression who go on to develop Alzheimer’s do so about two years earlier than those without depression. Those with anxiety who develop Alzheimer’s are given a diagnosis about three years earlier, on average, than those without anxiety.

The findings underscore the importance of screening for mental health disorders like depression and anxiety among older men and women, and raise interesting questions about the interplay of mental health problems with Alzheimer’s disease.

For the study, researchers screened 1,500 people with Alzheimer’s disease who were seen at the University of California, San Francisco, Memory and Aging Center. They looked to see who had a history of psychiatric disorders, including depression, anxiety, bipolar disorder, schizophrenia and post-traumatic stress disorder (PTSD).

Depression was by far the most common psychiatric diagnosis in the group — some 43 percent of the group had a history of depression. Anxiety was also common, affecting almost a third of participants. Bipolar disorder, PTSD and schizophrenia were far less common, affecting 1 percent or less of the group.

The researchers found that among those who develop Alzheimer’s disease, those with depression or anxiety start experiencing memory and thinking problems two to three years earlier than those without these conditions. Those with both conditions developed Alzheimer’s almost three-and-a-half years earlier than those who had no psychiatric conditions. And those who had three or more psychiatric diagnoses developed Alzheimer’s more than seven years earlier than those who had none.

“More research is needed to understand the impact of psychiatric disorders such as depression and anxiety on the development of Alzheimer’s disease, and whether treatment and management of depression and anxiety could help prevent or delay the onset of dementia for people who are susceptible to it,” said study author Dr. Zachary A. Miller, of the University of California, San Francisco.

“Certainly this isn’t to say that people with depression and anxiety will necessarily develop Alzheimer’s disease,” Dr. Miller added. “But people with these conditions might consider discussing ways to promote long-term brain health with their health care providers.”

The findings, to be presented at the American Academy of Neurology’s annual meeting, are preliminary. But they raise interesting questions about the interplay between mental health and Alzheimer’s disease.

Earlier studies have found that symptoms of depression and anxiety are linked to an increased risk of Alzheimer’s disease. But it is important to mention that it is unknown whether these conditions might be a cause or an effect of the disease. Along those lines, it is also well established that keeping a brain engaged through activities such as social interactions, staying physically active and novel pursuits is very beneficial to cognitive health. Depression and chronic anxiety are clearly not favoring these type of activities.

Researchers speculate that in some people, Alzheimer’s could be a long process that begins many years before the actual onset of memory loss, possibly showing up as symptoms of depression or anxiety in the early stages of the disease. Alternatively, it is also possible that depression and anxiety — and the chronic distress these conditions bring — may in some way weaken the brain, making it more vulnerable to the ravages of Alzheimer’s and other forms of dementia.

Certainly, developing memory problems, or getting a diagnosis of Alzheimer’s or another form of dementia, is a stressful event that might lead to symptoms of depression or anxiety, at least in the short term. If you experience unusual changes in mood or behavior, consult your physician. Medications and therapeutic counseling are available that can provide relief.

By ALZinfo.org, The Alzheimer’s Information Site. Reviewed by Marc Flajolet, Ph.D., Fisher Center for Alzheimer’s Research Foundation at The Rockefeller University. 

Source: Emily Eijansantos, Isabel Allen, Jessica Deleon, et al: “History of Psychiatric Disease Inversely Correlates with Age of Onset in Alzheimer’s Disease.” To be presented at the American Academy of Neurology’s 73rd annual meeting, April 17 to 22, 2021


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