The nicotine addicts have been found twice more prone to the symptoms of depression as compared to the non-smokers. This has been discovered by the researchers from Otago University's long-running Christchurch Health and Development Study.

On the other hand, the study also unveiled that the smokers possessed with a predisposition to the mental sickness, for them these risks are unrelated. Continuous debates are going on over the issue if smoking can cause mental health ailments, which is being discussed vigorously in the scientific community, these days.

Professor Ian Hickie, Executive Director of the Brain and Mind Research Institute at the University of Sydney, said, "The idea that smoking is actually relieving anxiety or protecting people from going on to develop depression is wrong. People are very interested in the neuro-chemical effects of nicotine to the extent in which they may actually cause mental health harm".

But, if we consider the vice-versa of this study, those people who are likely to get depression are also more prone to smoke, that is not the case. It has been said by a lead researcher Professor David Fergusson, further accepting the fact that smoking has increased the number of people to develop depression.