Smoking increases depression risk

Chronic smokers have a higher risk of depression as compared to those who do not smoke. Smoking is linked with depression, but whether it is the cause is debated. Nicotine in cigarettes has some mood-elevating properties, but in the long-run chronic exposure to cigarette smoke is associated with depressive symptoms. The researchers from the University of Helsinki, Finland analysed smoking behaviour as a predictor of depression among the Finnish adult twin population. They monitored the health and behaviour of 4,000 male and 5,000 female twins for 15 years. The results suggest that persistent chronic smoking predicts the development of depressive symptoms. However, when adjusted for other factors associated with depression, the elevated risk of depression with persistent smoking remained significant only among men. It was also found that people who had quit smoking, were also at an increased risk of depression, but only in the short term. Smokers who quit and remained off cigarettes in the long run did not have an increased risk for depression as compared to those who never smoked. This may reflect a relatively long recovery process from the adverse effects of cigarette smoking. When people start smoking, the immediate effects of nicotine in the brain are rewarding and pleasurable. This leads to self-medication, where a person who has mood problems seeks relief via cigarettes, and dependence because addiction to nicotine is as strong as an addiction to heroin. Smokers who are vulnerable to depression may need specific treatment and behavioural support to overcome the earlier phase of abstinence, after which their chances to quit successfully improve.