People who receive a diagnosis of cancer — especially a form of cancer that’s particularly lethal — are at increased risk of committing suicide or suffering fatal cardiovascular episodes in the days and weeks after their diagnosis. Those risks are highest right after the diagnosis and may linger, though diminished, for months to come.

Those are the sobering findings of a study published Thursday in the New England Journal of Medicine. The research supports the notion that a cancer diagnosis itself, independent of the effects of living with cancer and enduring cancer treatment, is an extremely stressful life event that can trigger dangerous physical and psychological effects.

Researchers examined data for more than 6 million people collected from 1991 to 2006 by the Norwegian government. Comparing data for people with and without a cancer diagnosis, they found that during the first week after their diagnosis, those with cancer were at 12.6 percent greater risk of committing suicide and 5.6 percent greater risk of dying of cardiovascular illness than those without cancer. At 52 weeks after diagnosis, those diagnosed with cancer were at 3.1 percent higher risk of suicide. At four weeks after diagnosis, people diagnosed with cancer were at 3.3 percent higher risk of dying from cardiovascular disease; by a year after diagnosis, though, that risk was about the same as for those without a cancer diagnosis.

The researchers controlled for underlying conditions that might contribute to cancer risk, suicide risk and cardiovascular disease risk. They also looked at the potential effects of preexisting cardiovascular and psychological conditions and their relationship to increased risk of post-cancer-diagnosis heart failure or suicide. They found that among the whole study population, the risks of both suicide and cardiovascular death were increased among those with such preexisting conditions, but that those risks were greatest for those without such preexisting conditions.

The findings held equally for men and women. But they varied substantially according to the likely prognosis for the form of cancer diagnosed: Risks of suicide and cardiovascular death were much higher for those diagnosed with cancers of the pancreas, esophagus, liver and lungs — all highly lethal — than for, say, skin cancer.

The authors note that the risk of suicide and death from cardiovascular disease after a cancer diagnosis may be even greater than their data reveal, as they looked only at actual deaths from suicide and heart failure without including all suicide attempts or non-fatal cardiovascular events.