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Alzheimer's Disease and other Dementias

The Depression/Dementia Connection

Editor’s note: Depression can be devastating for the sufferer and his or her loved ones, but when paired with dementia, it can be especially heartbreaking. Here, from the experts at Generations Healthcare, a network of skilled nursing, memory care and rehabilitation facilities in California, is an explanation of the link between depression and dementia, and how to manage it:

Dementia is a group of conditions that impairs the brain, affecting over47.5 million sufferers worldwide and 3 million U.S. cases per year. With sudden memory loss, language changes, memory disorders, personality changes, and impaired reasoning all seemingly effects of the disease, dementia is impossible to ignore as a cultural phenomenon.

What the media hasn’t covered at length is the increasing data pointing to links between depression and dementia. New studies and evidence are exposing a strong link between depression, dementia and Alzheimer’s. (Although the terms “Alzheimer’s” and “dementia” are often used interchangeably, they are different conditions.) The key to predicting and preventing dementia, the baby boomers’ most feared disease, may be staring back at us in the form of America’s most common mental illness, depression.

Signs of depression may be an early indication that dementia is developing in the brain before the telltale signs of memory loss appear. High levels of depression prior to a dementia diagnosis have been linked to more drastic decreases in thinking and memory skills later on. Researchers from Erasmus Medical Center in the Netherlands found that elderly people who developed increasingly worse depressive symptoms were more likely to develop dementia.

Researchers examined 3,325 people, aged 55 and older, as part of a population study dating back to 1990. Their goal was to examine the tentative link between depression and dementia. They found that 21% of people whose depressive symptoms increased over time were eventually diagnosed with dementia. By comparison, only 10% of people with “low symptoms of depression” developed dementia.

High levels of depression prior to a dementia diagnosis were linked to a more drastic decrease in thinking and memory skills later. Depressive symptoms that gradually increase over time appear to be a strong predictor of dementia later in life. Inflammation in the brain is seen in episodes of depression and cognitive decline. Inflammation may be the key to understanding this link.

Another study, published in the journal Neurology, found that people with more symptoms of depression suffer a more rapid decline in thinking and memory skills as they age. The study involved over 1,700 people who had no cognitive or memory problems. Participants were screened every year for symptoms of depression, such as loneliness and lack of appetite, and took tests on their thinking and memory skills for an average period of eight years.

About half of the participants developed mild problems with memory and thinking abilities that often appear as a precursor to Alzheimer’s disease. Depression accounted for about 4.4 percent of the difference in mental decline that could not be attributed to dementia-related damage found in the brain, the researchers found.

Alzheimer’s, a disease that causes 60% to 80% of cases of dementia, also has a strong link to depression. A startling 40 percent of Alzheimer’s patients suffer from severe depression, according to the Alzheimer’s Association. These mood and behavioral changes often precede memory problems in people with Alzheimer’s.

Studies have also shown that 90 percent of people with Alzheimer’s experience behavioral or psychological symptoms such as depression, anxiety and agitation. Studies suggests that these changes begin before people have diagnosable dementia. The people who developed dementia during the study also developed behavior and mood symptoms like appetite changes, irritability, general apathy and depression sooner than the people who did not develop dementia.

This data was backed up by a 2015 study in Neurology. Researchers found that for people who develop Alzheimer’s disease, depression and other “noncognitive” changes occurred before any of the typical memory and thinking problems associated with the disease were witnessed.

Three Types of Depression/Dementia Sufferers

There are three general groups of people who suffer from both depression and dementia:

  1. People who have battled lifelong depression. Lifelong sufferers are more likely to experience dementia.
  2. People who develop depression after memory loss and dementia. These people may experience depression as a reaction to these changes in their lives.
  3. People who develop depression, anxiety or a change in behavior, like being short-fused, agitated or aggressive, and then a short while after develop dementia.

By understanding how depression and dementia interact together, some day doctor’s may be able to identify elderly patients’ risks for dementia.

Though the link between depression and dementia is strong, science has not found causation from depression or dementia. This means, by treating depression, you’re not necessarily lowering the risks of dementia in patients. Regardless, treating geriatric depression is a major step towards reducing the complications of aging.

Just like the common tropes of exercise and healthy eating tell you, taking proactive steps is key to reducing the symptoms of depression. If you’re depressed, you may not want to pursue hobbies or see friends, but we know isolation and disconnection only make depression worse. The more engaged you are— socially, mentally, and physically—the better you’ll feel . Do your best to see people in person on a daily basis. Your mood will thank you!

Remember, it’s never too late to build new friendships. Start by joining a senior center, a book club, or another group of people with similar interests. Try new activities like Tai Chi, photography or crafting. Staying engaged is crucial to your health. It may just be your key to preventing dementia.

This article is reprinted courtesy of Generations Healthcare, a network of skilled nursing, memory care and rehabilitation facilities in California. Click here to visit their website.