One in 12 stroke survivors thought about suicide or that they would be better off dead, a troubling federal survey reveals. That’s more than those with other health problems such as heart attacks or cancer, and it suggests that depression after stroke is more serious than many had realized.

“It was surprising” and shows a need for more treatment, said the study’s leader, Dr. Amytis Towfighi of the University of Southern California. “When patients have their depression treated they’re more motivated to take their medication, do therapy and live a full life.”

More than 6 million Americans have had a stroke; about 800,000 occur each year in the U.S. Studies suggest that up to a third of stroke survivors develop depression, but few have looked at suicidal thoughts — one sign of how serious it is.

“It’s not necessarily active suicidal thoughts with a plan, but perhaps wishing you hadn’t survived the event,” Towfighi explained.

For the study, she used the National Health and Nutrition Surveys, a government project that gives checkups and questionnaires to a representative sample of adults. More than 17,000 people were surveyed.

About 8 percent of stroke survivors reported suicidal thoughts, compared to 6 percent of heart attack survivors, 5 percent of those with diabetes and 4 percent with cancer.