NOVEMBER / DECEMBER 2003
AROUND HARVARD
This article originally appeared in the September 2003 Harvard Health Letter and is provided courtesy of Harvard Health Publications.
Depression in old age
Most people, surveys show, become happier, or at least
more serene, as they grow older. But that does not mean depressive symptoms
and clinical depression necessarily become less common. They persist and
recur, complicating all the ills of later life. The symptoms are similar
in old age and in youth: fatigue; appetite loss; insomnia; difficulty concentrating;
loss of interest in life or the ability to enjoy it; feelings of emptiness,
guilt, sadness, and hopelessness; wishing for death; and thinking of suicide.
The treatments, too, are similar. But there are some variations and complications
that require special attention.
At any given time about 15% of people over 65 have significant depressive symptoms,
and about 3% — the same proportion as in youth — are suffering
from major depression. Another 2% have dysthymia, a form of depression with
less severe but longer-lasting symptoms. More women than men are depressed
at all ages, but later in life the ratio comes closer to 50–50.
To the common risk factors for depression in youth — heredity, chronic
and acute stress, drug and alcohol abuse, lack of material support or emotional
sustenance from others — old age often adds physical disability, chronic
medical illness, cognitive decline, and bereavement, especially the death of
a wife, husband, or life partner. People caring for a family member with chronic
illness — particularly a dementing disorder — also have a high
rate of depressive symptoms and clinical depression.
Depression, mortality, and physical illness
Even more in old age than in youth, depression is a killer. Suicide is one
of the reasons. In men the rate of suicide rises with age; white men over 50,
10% of the American population, make up 30% of suicides. A psychological autopsy
(see Harvard Mental Health Letter, May 2003) of 80 people who committed suicide
at an average age of 68 found that 50% of them had a known history of major
depression.
Depression and physical illness can also be a deadly combination. Depression — or
at least depressive symptoms — are common in response to serious illness
of any kind. Some diseases, including multiple sclerosis, hypothyroidism, lupus,
hepatitis, AIDS, vitamin deficiencies, and anemia, may produce depression in
a more direct biological sense. Drugs that can cause depressive symptoms include
antihistamines, anti-anxiety drugs, blood pressure medications, steroids, and
antibiotics. A careful medical history and physical examination are important
before diagnosing depression at any age, but especially in the elderly.
| Resources Depression and Bipolar Support Alliance 800-826-3632 (toll free) www.dbsalliance.org National Family Caregivers Association 800-896-3650 (toll free) www.nfcacares.org National Institute of Mental Health 301-443-4513 (toll free) www.nimh.nih.gov |
Equally important, depression itself raises the risk of physical disability,
physical illness, and death from physical illness. People with major depression
often fail to get the medical care they need because of isolation, passivity,
and pessimism. They complain more of pain and spend more time in bed than
people with heart disease or arthritis. Depression raises the risk of death
after a heart attack or stroke five times (see Harvard Mental Health Letter,
April 2003), possibly because it triggers the release of stress hormones,
causes heart rhythm disturbances, increases blood clotting, or weakens the
immune system. In one study, depression raised the death rate in a nursing
home by 50% over several years, independent of a resident’s physical
health at the beginning of the study.
| Depression and dementia One aspect of late-life depression that creates some confusion is its relationship with cognitive impairment and dementia. Distinguishing between depression and the early stages of dementia can be difficult because they often have symptoms in common — especially irritability, inability to concentrate or feel pleasure, loss of interest in life, and lack of energy and initiative. The cognitive deficits that sometimes appear in older depressed patients have inspired the concept of pseudodementia — depression masquerading as dementia. With care, though, it is often possible to make the distinction. People suffering from dementia are more likely to show signs of disorientation and loss of short-term memory. They are less likely to feel sadness and guilt or complain about pain, insomnia, and poor appetite. Researchers have become more interested in the close association between depression and true dementia. One study has found that about a third of Alzheimer’s patients develop symptoms of major depression, especially in the early stages of their decline. Late-life depression is more common in people with a family history of dementia, which suggests either that the disorders are genetically related or that depression is often an early sign of dementia. Older people with even a few depressive symptoms are at much higher than average risk for cognitive decline. And major depression has been linked to an increased risk for dementia occurring as much as 25 years later. Some studies have found a correlation between lifetime depression and the size of the hippocampus, the brain region that consolidates memories and is the first to deteriorate in Alzheimer’s disease. Depression may damage the hippocampus by stimulating stress hormones — the same way it is thought to damage the heart. In some cases, depression and dementia are apparently signs of a single underlying process. Many researchers believe that a condition called vascular depression appears as an early stage of vascular (multi-infarct) dementia, which results from tiny strokes that destroy patches of brain tissue. Something similar could be happening when depression accompanies Alzheimer’s disease. Both depression and dementia could arise from the disruption of circuits linking the prefrontal cortex — the seat of planning, initiative, and judgment — with the hippocampus and other lower brain regions. The standard treatments for depression will usually benefit people with both depression and dementia. Selective serotonin reuptake inhibitors are safe when taken along with the anticholinesterase drugs prescribed to slow the progress of Alzheimer’s disease. One study combined psychotherapy for people with Alzheimer’s disease (emphasizing a review of happy times in their lives) and problem-solving training for relatives who were caring for them. Depression improved in both patients and caregivers. |
Drug treatment
Older people are often left out of controlled trials for the treatment of depression,
especially if they are cognitively impaired or have serious medical problems.
There is little controlled research on the treatment of dysthymia and minor
depression (a milder form of major depression), which may be especially common
in old age.
Still, enough evidence is available to convince experts that antidepressant
drugs work equally well early and late in life. But older people usually absorb
and eliminate drugs more slowly and are more sensitive to side effects. And
they are often taking several medications, which raises the risk of dangerous
interactions. For all these reasons, the rule in prescribing drugs for the
elderly is to start at a low dose and raise it only gradually.
The preferred drugs, because of their relatively mild side effects and low
overdose risk, are the selective serotonin reuptake inhibitors (SSRIs), for
example sertraline (Zoloft) and citalopram (Celexa). The most common side effects
are nausea, insomnia, nervousness, agitation, tremors, headache, and sexual
problems. By inhibiting certain liver enzymes, SSRIs can raise blood levels
of anti-anxiety drugs, antipsychotic drugs, and drugs that control heart rhythm
(see Harvard Mental Health Letter, October and November 2000).
As many as 40% of older people taking antidepressants quit or repeatedly miss
doses because of side effects, memory problems, or difficulty keeping track
of complicated drug regimens. The best way to ensure that they continue to
take their drugs is maintaining a good relationship with a physician. Involving
a family member may also help.
Electroconvulsive therapy is effective for adults of any age and can be as
safe as or safer than medications. It is used especially in cases of psychotic
or life-threatening depression — patients who are delusional, suicidal,
or refusing to eat and drink.
Psychotherapy
Meta-analyses of many studies show that psychotherapy in all its standard forms
can be helpful for older people, especially if they are under severe stress,
lack social support, or will not or cannot take medications regularly. The
Division of Clinical Psychology of the American Psychological Association has
described cognitive behavioral, psychodynamic, and interpersonal therapies
as “probably efficacious” for late-life depression. As in younger
people, the combination of drugs and psychotherapy is probably better than
either treatment alone. In one study, 1,800 depressed people over age 60 were
followed for a year. Half of them worked with specially trained nurses or psychologists
and were allowed to switch between psychotherapy, drug treatment, or a combination
of the two as needed. The other half received standard care, usually consisting
of antidepressant drugs and monitoring. After a year, the first group had considerably
fewer serious symptoms of depression.
The outlook
Many questions remain for research. Various combinations of drugs and psychotherapy
have not been tested. More needs to be learned about how medical illness and
physical disability complicate the treatment of depression in old age. Many
experts believe that in judging the results of treatment, we need to pay more
attention to functional disability and illness, rather than just the standard
depressive symptoms.
Given the human and economic costs of late-life depression, it is most important
that we ensure patients a better chance of getting help. Mental health and
medical services should be better coordinated to reduce the burden of depression
and physical illness and their mutual effects. Physicians and the elderly need
to be better educated to recognize depression and take action. And everyone
needs to understand that depression can be as serious a health problem as any
of the more widely acknowledged diseases of old age.
References Karel MJ, et al. Assessing
and Treating Late-Life Depression: A Casebook and Resource
Guide. Basic Books, 2002. |
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