Six percent of American teenagers say they have tried to commit suicide, and 15 percent say they have come close to trying, according to a Gallup poll.

Three out of five of those surveyed in the poll, released Monday, said they knew a teenager who had attempted suicide; 15 percent said they knew a teenager who had succeeded in taking his or her own life.Thirty-nine percent said no one had known how upset those teenagers who had tried suicide were.

But 31 percent said the person who had tried suicide had exhibited warning signs such as depression and withdrawal or had talked or written about wanting to die.

Of those teenagers who said they had tried or come close to trying suicide, 47 percent blamed family problems or problems at home, 23 percent cited depression, 22 percent cited problems with friends, 18 percent cited feeling worthless and 16 percent cited boy-girl relationships. Some gave more than one reason.

Gary Hoeltke, senior analyst for the survey and a former school psychologist, said the poll proved that "society has not addressed one of the major problems we've got. Your third-largest cause of death among adolescents is suicide, yet you don't really see anybody systematically addressing this."

Forty-one percent of the teenagers polled said their school was providing counseling or seminars on suicide prevention. "By default that's 60 percent that offer nothing," Hoeltke said.

A fifth said their community offers a suicide hot line, counseling or seminars. Twenty-eight percent said their church or synagogue had suicide prevention programs.

More than 80 percent felt that communities, schools and religious institutions should offer programs to help teenagers handle their problems.

Twelve percent said a member of their family had attempted suicide. Five percent said a member of their family had committed suicide.

The poll, conducted nationwide between November and January among 1,152 people age 13 to 19, has a margin of error of plus or minus 2.9 percent.

Hoeltke said experts who reviewed the data concluded that if anything, the poll underestimates the problem because the respondents represented a higher income group and included more white teenagers than the population at large. Suicide rates are higher among lower-income and minority teenagers, he said.