Using actual body size based on teens' reports of their height and weight, the researchers found that overall, overweight or underweight teens were only slightly more likely than normal-weight teens to have suicidal tendencies.
But teens who perceived themselves at either weight extreme — very fat or really skinny — were more than twice as likely as normal-weight teens to attempt or think about suicide.
The study was based on a nationally representative 2001 survey involving 13,601 students in ninth through 12th grade. The findings appear in the June issue of Archives of Pediatrics & Adolescent Medicine, published Monday.
About 19 percent said they had considered suicide in the previous year and about 9 percent said they had attempted it.
About 65 percent of students were in the normal-weight range, but only about 54 percent perceived themselves as "about the right weight." Some thought they weighed too much; others thought they were too thin.
"Suicide ideation was more likely even among students whose perceptions of body size deviated only slightly from `about the right weight,"' said lead author Danice Eaton, a researcher at the Centers for Disease Control and Prevention.