Research
over the past two decades has shown that depression and heart
disease are common companions and, what is worse, each can
lead to the other. It appears now that depression is an important
risk factor for heart disease along with high blood cholesterol
and high blood pressure. A study conducted in Baltimore, Maryland
found that of 1,551 people who were free of heart disease,
those who had a history of depression were four times more
likely than those who did not to suffer a heart attack in
the next 14 years. In addition, researchers in Montreal, Canada
found that heart patients who were depressed were four times
as likely to die in the next six months as those who were
not depressed.
Depression may make it harder to take the medications needed
and to carry out the treatment for heart disease. Depression
also may result in chronically elevated levels of stress hormones,
such as cortisol and adrenaline, and the activation of the
sympathetic nervous system (part of the "fight or flight"
response), which can have deleterious effects on the heart.
The first studies of heart disease and depression found that
people with heart disease were more likely to suffer from
depression than otherwise healthy people. While about 1 in
20 American adults experience major depression in a given
year, the number goes to about one in three for people who
have survived a heart attack. Furthermore, other researchers
have found that most heart patients with depression do not
receive appropriate treatment. Cardiologists and primary care
physicians tend to miss the diagnosis of depression; and even
when they do recognize it, they often do not treat it adequately.
The public health impact of depression and heart disease,
both separately and together, is enormous. Depression is the
estimated leading cause of disability worldwide, and heart
disease is by far the leading cause of death in the United
States. Approximately one in three Americans will die of some
form of heart disease.
Studies indicate that depression can appear after heart disease
and/or heart disease surgery. In one investigation, nearly
half of the patients studied one week after cardiopulmonary
bypass surgery experienced serious cognitive problems, which
may contribute to clinical depression in some individuals.
There are also multiple studies indicating that heart disease
can follow depression. Psychological distress may cause rapid
heartbeat, high blood pressure, and faster blood clotting.
It can also lead to elevated insulin and cholesterol levels.
These risk factors, with obesity, form a constellation of
symptoms and often serve as a predictor of and a response
to heart disease. People with depression may feel slowed down
and still have high levels of stress hormones. This can increase
the work of the heart. As high levels of stress hormones are
signaling a "fight or flight" reaction, the body's
metabolism is diverted away from the type of tissue repair
needed in heart disease.
Regardless of cause, the combination of depression and heart
disease is associated with increased sickness and death, making
effective treatment of depression imperative.
Pharmacological and cognitive-behavioral therapy treatments
for depression are relatively well developed and play an important
role in reducing the adverse impact of depression. With the
advent of the selective serotonin reuptake inhibitors to treat
depression, more medically ill patients can be treated without
the complicating cardiovascular side effects of the previous
drugs available.
Exercise is another potential
pathway to reducing both depression and risk of heart disease.
A recent study found that participation in an exercise training
program was comparable to treatment with an antidepressant
medication (a selective serotonin reuptake inhibitor) for
improving depressive symptoms in older adults diagnosed with
major depression. Exercise, of course, is a major protective
factor against heart disease as
well.
(Source: National Institute of Mental Health)
See “Depression” for
more on depression risk and symptoms.
See Mental Health for more
mental health articles.
