CHICAGO (American Medical Association) -- Many common illnesses are independently associated with an increased risk of suicide in elderly people, according to an article in the June 14 issue of The Archives of Internal Medicine, one of the JAMA/Archives journals.

According to information in the article, suicide is the 11th leading cause of death in the United States and is especially common among the elderly. Elderly people in many countries kill themselves at a rate higher than any other segment of the population. Medical illnesses may predispose to suicide, but few studies have examined the association between suicide and specific illnesses, the article states.

David N. Juurlink, M.D., Ph.D., of Sunnybrook and Women's College Health Sciences Centre, Toronto, Ontario, and colleagues examined the relationship between treatment for several illnesses and the risk of suicide in elderly patients.

The researchers examined the prescription records of all Ontario residents 66 years and older who committed suicide between January 1, 1992 and December 31, 2000. For each resident who committed suicide, the researchers also looked at the prescription records of four living controls matched for age, sex, residential area, and income to determine the presence or absence of 17 illnesses potentially related to suicide.

Among the 1,329 elderly persons who committed suicide (1,012 men; 317 women), the most common methods involved firearms (28 percent), hanging (24 percent), and self-poisoning (21 percent).

Depression, bipolar disorder (manic-depressive illness) and severe pain were associated with the largest increases in suicide risk. However, several other chronic illnesses including seizure disorder, congestive heart failure, and chronic lung disease, were also associated with an increased risk for suicide. The researchers also found that treatment for multiple illnesses was strongly related to an increased risk of suicide, and that most of the patients who committed suicide visited a physician in the month before death, about half of them during the preceding week.

"Our findings have important implications for prevention because most elderly patients who commit suicide visit a physician shortly beforehand, and many of them have clinically recognizable features of depression at the time," the authors write.

"Physicians, nurses, and other health care professionals should be alert to the possible threat of suicide in elderly patients with chronic illness, particularly in patients with multiple illnesses, symptoms of depression, or other risk factors for suicide."