DEPRESSION MUST BE CONSIDERED A RISK FACTOR FOR HEART DISEASE

In the May 27^th 2009 issue of the Journal of the American Medical Association on the Patient Page eight risk factors for heart disease are listed. They are as follows:

• Smoking
• High Blood Pressure
  
• A high level of low-density lipoprotein (LDL; bad cholesterol) especially when associated with a low level of high-density lipoprotein (HDL; good cholesterol)
• High levels of triglycerides (another form of fat found in the bloodstream that can contribute to heart disease)
• Diabetes

• Overweight (body mass index [BMI] greater than 25) or obesity (BMI greater than 30)

• Excessive alcohol use

• Family history of premature death (before age 65) from heart disease.

In my opinion a crucial risk factor was omitted and an opportunity was missed to educate the public about an important approach to limiting heart d isease and maybe even preventing death from this killer. There is ample evidence based research for listing depression as a risk factor for heart disease.

POSSIBLE MECHANISMS

Depression  and Blood Clotting

There is also a pretty good idea as to the physiological mechanisms which connect depression and heart disease. For example, when the platelets in the body are activated a thrombus or clot is formed which can lead to a coronary artery heart blockage and hence a heart attack. Studies have compared this clotting phenomenon in a healthy population without heart disease using both a depressed and a non-depressed group. There was an increase in the clotting activity of the depressed over the non-depressed group.

Depression  and Heart Variability

Another mechanism concerns the HRV or heart rate variability .When the heart is stressed physically or emotionally it has the ability to speed up and slow down depending on the degree of stress. This can be monitored by a 24 hour/day device which can be worn by a person who can keep track of their events. After a heart attack if there is a decreased HRV meaning the heart has lost some ability to respond to stress that has been shown to predict potentially fatal heart rhythms. There is also evidence that has shown depressed mood, whether one has cardiac disease or not, is associated with reduced HRV.

Depression and the Inflammatory Process

In addition, depression has been shown to be characterized by an increase in markers of the inflammatory process, particularly substances known as Interleukin -6 and C-reactive protein (CRP). Both of these factors have also been implicated in bringing about Coronary Artery Disease. However, depressed individuals even without heart disease have elevated levels of these substances. Depression leads to the body producing increased cortisol (the stress hormone) which may produce these inflammatory markers. However most recent research published this month  suggests that there is a genetic link to the production of CRP which may not be connected to heart disease, making these connections less significant.

DEPRESSION AND DEATH FROM HEART DISEASE

Pre-existing depression prior to the development of heart disease is associated with a poor outcome in patients who subsequently develop heart disease and need a coronary artery bypass graft. Not only are such people more likely to die but they are more likely to have prolonged pain and are less likely to return routine activities. There are similar findings in people who have had congestive heart failure. In addition, if there were two people in the intensive care unit after a heart attack with the same degree of damage and one was depressed and the other was not , the depressed person would have a four times greater chance of dying in the next six months than the non depressed patient.

RELATIONSHIP BETWEEN DEPRESSION AND OTHER RISK FACTORS

The connection between depression and heart disease can stand on its own. However, even if you just look at the risk factors listed at the beginning of this piece which were given in the JAMA article mentioned above, we will find a linkage to many psychological factors including depression. In addition, depression is usually co-morbid meaning it co-exists with most other psychological symptoms. Depression also can limit a persons ability to cooperate with treatment, especially with diet and exercise which are often a major component of the recommendations which are made to the person with cardiac risk factors. I will briefly review some of the connections to these risk factors.

Smoking - Often engaged in during times of distress including depression. May become part of an obsessive behavior pattern. Leads to addiction to nicotine. Failure to succeed in cessation often leads to depression which causes a vicious cycle

High Blood Pressure- Psychological stress such as severe anxiety, but also depression, can cause elevated blood pressure especially in individuals predisposed to hypertension.

Diet Related Factors (Inability to control proper levels of various types of cholesterol and triglycerides as well as objective obesity)- People with depression often overeat, although individuals with severe depression often have diminished appetite. Obesity can complicate the treatment of hypertension and diabetes.

Diabetes – The issues of diet are intertwined with diabetes and thus with depression. In one study of 6000 people with varying degrees of depression but no diabetes at the start of the study, it was found that 6 % developed diabetes over the next 20 years. Those with high degrees of depression were more than 2 times more likely to develop diabetes. That group was also more likely to be less active, more likely to smoke and more likely to be obese.

Excessive Alcohol Use- Depression and excessive alcohol reinforce each other in many ways. The pain of depression can lead to self medication with alcohol in an attempt to relieve such feelings. Alcohol is a depressant to the central nervous system which can intensify pre-existing depressive tendencies. In addition the despair and difficulty in breaking alcoholic dependency can precipitate severe depression.

( image from: link to freedigitalimages.com )

Family History of Premature Death (before age 65) from heart disease-When a person knows that they have a family history which makes them more likely to have a serious illness such as heart disease at a young age, they often feel as though they are a “walking time bomb”. As they come closer to the age of the expected illness, despair and depression may very well become prominent. George Engel described the Nemesis Complex in this regard related to the dates of heart attacks of his father and then his identical twin

As depression brings about any of the above risk behaviors or exacerbates them, so is the individual more likely develop heart disease and symptoms.

PREVENTION OF HEART DISEASE BY TREATMENT OF DEPRESSION

Good health care would dictate behavior to eliminate any risk factor for heart disease and if possible do whatever you can to modify it. Since I contend that depression is one of these risk factors, treatment of depression is indicated when it exists or when there are precursors of depression such as major emotional conflicts. The type of treatment would obviously depend on the individual and might be psychopharmacology, some form of psychotherapy or a combination of these forms of treatment. In the days when tri-cyclic antidepressants (such as Elavil and others) were essentially the main form of psychopharmacology for depression there was the added problem that these medications had significant cardiac side effects. That is not the case with most of the medications used today for depression. In fact there has been some evidence that treatment with the SSRI (Prozac, Zoloft and others) type of medications will normalize the platelet and Heart Rate Variability problems discussed above There is a great deal of experience in treatment of depression in people with existing heart disease without deleterious effects. One of the research projects which demonstrated this is the SADHEART Study. There continues to be ongoing interest and research in this area.

Psychotherapy and medication may also be helpful in treating the other risk factors mentioned which could lead to diminished heart disease.

Finally, remember that depression is a condition that not only is a risk factor for heart disease and other medical illnesses but it is widespread and can be a devastating illness itself. The lifetime prevalence of depression in the general US population is 17.1 %. It is even higher in women (21%). According to the National Institute of Mental Health a suicide occurred every 18 minutes in the United States in the year 2000. It is estimated that at least 90% of completed suicides have diagnosable mental illness, usually a mood disorder. Treatment for depression does work and it can be life saving in more ways than one.

Related Links- Dr. Blumenfield interviews Dr. Lawrence Wulsin about Heart Disease & Depression on “Shrink Pod”