According to a new Kiwi research, smoking can raise the risk of depressive disorder.

The research, conducted by Otago University, suggested that nicotine-dependent individuals are more than twice as likely to get depressed as those who don’t smoke.

Researchers from the university''s Christchurch Health and Development Study quizzed over 1000 people about their smoking habits and symptoms of depression at ages 18, 21 and 25 to come up with their conclusion.

Lead researcher David Fergusson, stated, "Our findings are consistent with the conclusion that there is a cause and effect relationship between smoking and depression, in which cigarette smoking increases the risk of developing symptoms of depression.”

"The reasons for this relationship are not clear. However, it''s possible that nicotine causes changes to neurotransmitter activity in the brain, leading to an increased risk of depression," David added.

The results of the research appeared in the British Journal of Psychiatry. (With Inputs from Agencies)