For years, researchers have believed that suicidal behavior is contagious.
The assumption has influenced prevention programs and policies and, because it was thought especially true of young people, often led school counselors to avoid widespread discussions after a student committed suicide. Even the news media has been urged to downplay reports about suicides for fear of causing copycats.
Now research suggests that being exposed to accounts of suicide may actually keep people from trying it themselves.
The new study, conducted by researchers at the federal Centers for Disease Control and Prevention, casts significant doubt on the "copycat" theory. The results were published in the July 15 issue of the American Journal of Epidemiology.
Study Compares 2 Groups of People
Researchers spoke to 153 people, ages 13 to 34, who had "attempted near-lethal suicide" and compared them with a control group of 513 people who had never attempted suicide.
The researchers defined a near-lethal suicide attempt as a case in which a person would have died if he or she had not received emergency medical or surgical help or one in which a person used a gun or noose in a suicide attempt and had suffered an injury.
The study was conducted between November 1992 and July 1995 in the Houston area.
The researchers expected that people who had been exposed to the suicides of others would be more common in the group that had tried to kill themselves than in the group that had not.
Instead, even after taking into account the effect of depression, alcoholism and other known risk factors for suicide, the researchers found no evidence of a contagious effect.
"The control group was much more likely than the case group to be exposed to a friend or family member who had attempted suicide and was also much more likely to read about it or watch it on the news," said Dr. James Mercy of the CDC's National Center for Injury Prevention and Control. "We didn't expect that."
The question of whether contagion is a factor in people killing themselves is important because of suicide's prevalence. More than half a million Americans attempt suicide every year, according to federal statistics. Suicides outnumber homicides by a ratio of 3-2 in the United States.
Others' Experiences 'Diminish Aloneness'
Dr. Mark Goulston, a member of the Board of Directors for the American Foundation of Suicide Prevention, said that he tended to agree with the study's findings.
People attempt suicide for various reasons, but they are all similar in that they feel alone when they pull the trigger or take a pill, he said. "Reading about someone else can lessen the impulse to attempt suicide," Goulston said. "If you can diminish the aloneness, you can diminish the suicidal behavior."
Dr. Kay Redfield Jamison, professor of psychiatry at the Johns Hopkins School of Medicine agreed. The study was "illuminating," she said, adding that lack of research about suicide's causes has hampered prevention efforts. But others expressed doubts.
Dr. Edwin Shneidman, the founder of the American Assn. of Suicidology, said that the results have to be taken with a grain of salt.
"A statistical result by its nature masks individual differences," said Shneidman. Researchers need to look individually at people who have tried to commit suicide and not necessarily group them together, he said.
Rosemary Rubin of the Los Angeles Unified School District Suicide Prevention Unit, suggested, for example, that adolescents may be more susceptible to contagion factors than are young adults. The study may not have adequately distinguished between the two age groups, she suggested.
Mercy, however, said he and his colleagues were not able to find evidence of a larger impact of exposure for adolescents than for young adults.
More research will be needed to refine the group's findings, he said.
"This exposure to suicide is more complex than once thought," said Mercy. "This study forces us to think more broadly and better design preventive measures."
All that leaves the advice for those who must counsel friends, classmates or relatives of suicides somewhat uncertain.
"Having a family member attempt or commit suicide or having the media talk about it has an uncertain influence," said Dr. Jay Nagdimon, the director of the Suicide Prevention Center of Didi Hirsch Community Mental Health Center in Los Angeles.