"A link between cigarette smoking and suicide has been reported in epidemiological investigations since the 1970s," according to background information in the article. However, these interpretations have been subject to controversy. It is believed that depression may result in part from smoking and should not be controlled in analysis of this relationship. However, it's also been reported that symptoms of depression in adolescents predicts their starting smoking and that major depression leads to an increased risk for regular smoking and dependence; therefore, a history of depression must be considered when examining suicide in smokers.
Naomi Breslau, Ph.D., from Michigan State University, East Lansing, and colleagues examined the association between cigarette smoking and suicidal thoughts and attempts. Participants aged 21 to 30 years were interviewed in 1989 and completed follow-up interviews in 1992, 1994, and 1999 - 2001. At each assessment, they were asked about lifetime smoking history, whether they were current daily smokers or had been in the past, and psychiatric disorders. Nearly nine hundred people completed all three investigations.
During the ten-year follow-up, nineteen participants attempted suicide, while 130 reported having suicidal thoughts. The researchers found that current daily smoking, but not past smoking, as reported at the beginning of each of the assessments, predicted the subsequent occurrence of suicidal thoughts or attempt. These findings remained when adjusted statistically for prior depression, substance use disorders, prior psychiatric disorders and prior suicidal disposition. Rates of suicidal behavior were also higher in those experiencing depression at the start of each follow-up period.
"The biological explanation of the finding that current smoking is associated with subsequent suicidal behavior is unclear," the authors conclude.
(Arch Gen Psychiatry. 2005; 62: 328 - 334. Available post-embargo at www.archgenpsychiatry.com)
Editor's Note: This research was supported by a grant from the National Institute of Mental Health, Rockville, Md.
For more information, contact the JAMA/Archives Media Relations Department at 312-464-JAMA (5262) or email email@example.com