An alarming new study by a team of psychiatric scientists in Germany suggests that suicide is "strongly associated" with occasional or regular smoking.
The team of experts led by Thomas Bronisch of the Max Planck Institute of Psychiatry in Munich stressed that they could not find any direct causative link between smoking and suicide. They said more research is needed.
But Bronisch and his associates Dr Michael Hoefer of Technical University of Dresden and Roselind Lieb of the University of Basel wrote in a report in the Journal of Affective Disorders that there were compelling indications that suicide and smoking are somehow associated with each other.
"Campaigns for reducing smoking should also point to the elevated risk of suicide for occasional and regular smokers," the authors wrote.
Their findings are based on data from a study that began in 1995 with some 3,000 test subjects between the ages of 14 and 24 who lived in Munich. A follow-up study was conducted four years later, involving about two-thirds of the original test participants.
The test involved non-smokers as well as "occasional smokers" along with "non-depending regular smokers" and also hard-core "addicted smokers."
The non-smokers had the lowest rate (less than 15 percent) of what the scientists call "suicide ideation" - that is, having made plans to kill oneself and/or having seriously wanted to die for a period of at least two weeks.
The rate was around 20 percent among occasional and non-dependent smokers. However, nearly a third or 30 percent of smoking addicts had experienced suicidal ideation.
"Nicotine dependence increased the risk for new onset of suicide ideation," the authors wrote. "And prior regular previous smoking term and nicotine dependence increased also the risk for onset of suicide attempts."
Nearly 70 individuals had actually made suicide attempts.
But the researchers pointed out that none of the participants in the study had actually killed themselves.
The experts said none of the test participants had had a history of alcohol or drug abuse, nor had any of them had a history of clinical chronic depression.
"The presence of associations between prior previous smoking and subsequent suicidality, in concert with the lack of associations between prior suicidality and subsequent previous smoking suggests the existence of an independent pathway from previous smoking to suicidality," they wrote.
In other words, the more one smokes, the more probable one is to have suicidal thoughts or "suicidal ideation" as the psychiatrists call it.
The experts cautioned that the study involved only a limited age group - 14 to 24 years of age - and that much more study is needed.