Smoking increases risk of suicide: study

IAN MACLEOD
Postmedia News

Here’s another reason not to smoke – it has now been linked with an increased risk of suicide, independent of mental illness.

A novel new Canadian study of almost 35,000 adults found nicotine dependence is associated with suicide attempts regardless of the mental disorders and physical disease that often accompany suicidal behaviour.

It also supports previous research that describes nicotine as a “psychological toxin” that causes chemical changes in the brain associated with suicide.

What’s more, the work by the universities of Manitoba and Saskatchewan found suicidal tendencies diminished significantly among people who had quit smoking for at least a year. Former smokers were not only less likely to have attempted suicide than current smokers, but were less suicidal than lifelong non-smokers, which should give added momentum to smoking cessation programs.

These are important findings in a controversial field. Some previous studies have found a relationship between nicotine and suicide, but did not adjust for the effects of mental disorders.

The new study does and finds “this relation persists even after adjusting for a broad range,” of mental and personality disorders and physical disease.

The research, to be published in coming days in the Canadian Journal of Psychiatry, opens a new avenue in the campaign to eradicate smoking, the leading cause of preventable death in Canada and worldwide.

Understanding the neurobiology of suicide also could have enormous advantages, not only in efforts to reduce the number of suicides, but also in research targeting the biological mechanisms involved in depression.

Among the current smokers studied, the new research also found those who consumed more than 20 cigarettes daily had higher odds of attempting suicide than those who smoked 10 or fewer.