Healthy older Americans who are depressed may have a higher risk for developing coronary heart disease (CHD) and dying from all causes, according to the results of this six-year study.

Researchers followed close to 4,500 older people (age 65 or older), who did not have cardiovascular disease when they entered the study. The average age for men participating in the study was 73 years and for women 72 years. At the beginning of the study, each participant completed a standard questionnaire used to determine depression in older individuals. They also completed the same questionnaire each year for the next six years, or until they experienced a cardiac event. (A cardiac event was defined as angina, a myocardial infarction (MI), angioplasty, bypass surgery, or death.)

A "cumulative" average depression score was calculated for each participant - i.e. the total of their depression scores up to the time they had a cardiac event. The researchers first calculated an "unadjusted risk." Then they calculated a risk that took age, sex and other CHD risk factors into consideration.

There was a significant increase in the risk of developing CHD as participants depression score increased. Each 5-point increase was associated with a 16% increase in the risk of CHD and a 29% increased risk of death from all causes. After the scores were adjusted for age, sex, and other risk factors, every 5-point increase was associated with a 15% increase in the risk for CHD and a 16% increase in the risk of death.

There was also an increase in risk between those with the highest and those with the lowest depression scores at baseline. Individuals with the highest average depression scores had a 40% greater risk of CHD and a 60% greater risk of dying than those with the lowest scores.

By letting their physicians know that they feel depressed and by seeking treatment for depression, older Americans can lower their risk for developing CHD. Below, you can get an idea of the sort of symptoms that can put one at increased risk; it's a summary of the depression scale used in this study (the Center for Epidemiological Studies' Depression Scale):

Using the scale below, indicate the number that best describes how often you felt or behaved this way during the past week.

1. I was bothered by things that don't usually bother me
2. I had trouble keeping my mind on what I was doing
3. I felt that everything I did was an effort
4. I felt depressed
5. I felt hopeful about the future (this score is reversed, i.e. it's subtracted from the total)
6. I felt fearful
7. My sleep was restless
8. I was happy (this score is reversed, i.e. it's subtracted from the total)
9. I felt lonely
10. I could not get going

The 4-point scale is as follows:

• 0 = Rarely or none of the time (less than 1 day)
• 1 = Some or a little of the time (1 to 2 days)
• 2 = A moderate amount of the time (3 to 4 days)
• 3 = Most of the time

A score of 8 or more indicates someone 'at risk of clinical depression'.