Chain smokers are at a higher risk of developing depression in comparison to those who never smoke, a Finnish study has suggested.
The study conducted at the Department of Public Health of the University of Helsinki claims that those who quit smoking have an elevated risk of depressive symptoms but only in the short-term and this risk declines to the level of non-smokers in the longer-term.
The research was conducted on about 4,000 male and 5,000 female twins, whose health and health behavior were followed-up through 15 years.
As the study consisted of twins it was easier to test the relation between smoking and depression by using twin pairs where the twin without depression served as a harmonized control for his/her co-twin suffering from depression.
Twins also enabled the researchers to examine the genetic influences between depression/smoking link.
Dr Tellervo Korhonen from the University of Helsinki said,
The mechanisms underlying the association between smoking and depression are very complicated. Although nicotine as such may have short term positive effects on concentration and possibly on mood, long term exposure to tobacco smoke may be one risk factor in development of depression. However, this mechanism is still relatively unknown. Thus, there is need for further research and evidence in order to make an unambiguous statement that ’smoking cigarettes cause depression’. Examination of potential shared genetic vulnerability for both tobacco dependence and depression is among the further challenges.
The study also revealed that persistent smoking remained significant amongst men folk, whereas women were more likely to give up smoking at a particular stage.
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