People are more likely to commit suicide in the wake of a heart attack, and some are more at risk than others, a new study shows.
In the immediate aftermath of a heart attack the risk of suicide rises dramatically among people with a history of mental illness. These patients are about 60 times more likely to commit suicide than people who did not experience either a heart attack or mental illness.
Even for patients with no history of mental illness, the risk for suicide is tripled in the month after a heart attack - and the risk remains elevated for at least five years. This appears true for both men and women, and regardless of socio-economic status.
The findings, based on nationwide data from Denmark and reported in Circulation, are not a surprise, study author Dr Karen Kjaer Larsen of Aarhus University in Denmark said. "We know that many patients with myocardial infarction suffer from anxiety and depression," she said. "Our study shows that the mental pain due to MI for some people is so strong that they commit suicide."
As a result, Dr Larsen suggests that cardiac rehabilitation programs take mental health into consideration, along with cardiac status. She urges doctors to monitor patients for anxiety, depression, and suicidal thoughts. "Awareness of the mental strain and articulation of the issue is important to let the patients know that mental reactions to an MI are common," she said.
It's also important to ensure that people have social support after such a life-changing event, Dr Larsen added. "Before patients with MI are discharged from hospital we need to make sure that they have a safety net, and know where to go or who to call if they suddenly feel sad and cannot cope with the situation."
Previous research has shown that people are more likely to commit suicide after being diagnosed with other serious conditions, including stroke, epilepsy, and diabetes. To investigate whether the same risk occurs after heart attack, Dr Larsen and her colleagues examined population data from Denmark, collected between 1981 and 2006.
They identified almost 20,000 people who had committed suicide, and compared them to nearly 200,000 similar people who hadn't. They found that more than four percent of people who committed suicide had a history of heart attack, versus less than three percent of controls.
The risk of suicide was highest in the month after patients left the hospital. Risks were also particularly high in patients with a history of psychiatric illness (indicated by a previous admission to a psychiatric hospital, ward or outpatient clinic), and in patients less than 60 years old at the time of their heart attack.
This higher risk in younger patients also makes sense, Dr Larsen said, because young people are overall less likely to commit suicide. "Because risk factors for suicide are less frequent in the young people, the relative risk of a single risk factor tends to be stronger."
The authors did not report on the actual risk of suicide among those who had suffered heart attack. However, the overall suicide rate in the US population is quite low, about 35,000 per year among 300 million people. More than one million have a heart attack each year.
Dr Redford Williams at Duke University Medical Centre, who wrote an editorial about Dr Larsen's study, agreed that the overall findings make sense.
Stress precipitates depressive reaction
"Any sort of major life stressor and an MI certainly falls in that category is capable of precipitating a depressive reaction, especially in people who are predisposed, whether by genetics, past exposure to major stressors or both, to develop depression," he said.
Dr Williams added that he supports the recommendation of the American Heart Association that all heart attack patients be screened for depression, but cautioned that it's not clear yet whether treating depression will help the patient's heart or mental state.
What the field needs, he said, is a large study that tests whether antidepressants and other interventions help these patients, "so that we will be able to recommend interventions with confidence that they will reduce depression, recurrent cardiac problems and, hopefully, even suicide."
(Reuters Health, Alison McCook, December 2010)