Why are many elderly people forgetful? It may be the blues.
April 17, 2000 (Berkeley, Calif.) -- For years, Maria Cusenza's three
children didn't worry much about her. Through her 60s and early 70s, Cusenza
was a busy woman living in her own apartment in San Francisco. But in recent
years the situation has changed. Cusenza, now 80, has marked memory loss. By
afternoon, she forgets a conversation she had that morning. During the week she
forgets a weekend outing.
"We have to check on her more often, to make sure she is healthy and
safe," says Dorothy Cusenza, 57, one of Maria's two daughters. For the
first time Cusenza and her family are talking about home helpers, retirement
homes, or having Mom move in with one of her kids. As her forgetfulness
increases, she sinks farther and farther into depression.
Doctors are still trying to determine why Cusenza's memory is fading; they
say there's little they can do. But her family wonders if her depression might
be causing her memory problems rather than the other way around.
They are intrigued by new research showing that stress and depression may
cause some forms of memory loss. The research is important because it suggests
that not all memory loss is an inevitable part of aging. '"If you look at a
patient as having irreversible dementia, you won't do anything," says Sonia
Lupien, PhD, a neuroscientist at Douglas Hospital in Montreal. "If you
treat the depression, you can stop the increase of cortisol and prevent the
Studies show that prolonged depression or stress leads to elevated levels of
cortisol, a "stress" hormone produced by the adrenal glands. This in
turn appears to shrink or atrophy the hippocampus, the sea-horse shaped part of
the brain associated with many kinds of memory and learning.
"The hippocampus is an organ of the brain that is particularly
vulnerable to stress and stress hormones," says Bruce McEwen, the head of
neuroendocrinology at Rockefeller University in New York.
While cortisol levels normally fluctuate over the course of a day and night,
they often soar when a person is faced with a stressful situation, such as a
job interview or a school test. Studies have shown that this affects memory.
For example, researchers reported in the April 2000 issue of Nature
Neuroscience that people taking cortisone pills (which metabolizes to
cortisol in the body) were not as good at remembering a list of words as people
taking placebo pills.
For many people, depression appears to cause similar damage; their cortisol
levels remain slightly elevated as long as they are depressed. This moderate
but constant drip-drip of the cortisol faucet appears to wear down the
In a review of several long-term studies published in the October 1999 issue
of Reviews in the Neurosciences, Lupien concluded that this process is
particularly damaging in the elderly.