|
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. In a study conducted in Baltimore, it was found that of 1,551 people who were free of heart disease those who were depressed were four times more likely to have a heart attack in the next 14 years than those who were not. Researchers in Montreal 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 may also 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 showed that people with heart disease were more depressed than healthy people. While about one in six people have an episode of major depression, the number goes to one in two for people with heart disease. Furthermore, other researchers have found that most heart patients are not treated for depression. Doctors tend to miss the diagnosis of depression and even when they treat it they often treat it with sedatives which may make the depression worse.
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 of 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 patients.
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. Depressed individuals may feel slowed down and still have high levels of stress hormones. This can increase the work of the heart. When patients are caught in 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. Ongoing research is investigating whether these treatments also reduce the associated risk of a second heart attack. Furthermore, preventive interventions based on cognitive-behavior theories of depression also merit attention as approaches for avoiding adverse outcomes associated with both disorders. These interventions may help promote adherence and behavior change that may increase the impact of available pharmacological and beha vioral approaches to both diseases.
Exercise is another potential pathway to reducing both depression and heart disease. Exercise is related to fewer depressive symptoms in observational studies and appears to be as efficacious as psychotherapy in patients with mild depression. Exercise, of course, is a major protective factor against heart disease as well.
more on heart disease and depression
co-occurrence index
next: Co-Occurrence of Depression With Stroke
|
