Smokers more prone to depression

Researchers in Spain suggest that smokers are significantly more at risk of suffering depression than non-smokers.

The researchers from the the University of Navarra say that smoking increases the mental health risk by 41% in comparison with non-smokers.

The scientists led by Professor Almudena Sanchez-Villegas conducted a study involving 8,556 participants and worked in collaboration with the University of Las Palmas de Gran Canaria and the Harvard School of Public Health in the U.S.

The study was undertaken over the course of 6 years on university graduates with an average age of 42 and demonstrates the direct relationship between tobacco use and depression.

Professor Miguel Angel Martínez-Gonzalez, director of the research project from the Department of Preventive Medicine and Public Health, says over the study period 190 smokers who were initially not depressed were diagnosed with the illness by a doctor and another 65 who were not diagnosed indicated that they were taking antidepressants during this period.

The professor says the relationship between tobacco and depression indicates a possible "genetic and/or environmental disposition" which serves to increase the probability that the tobacco habit is retained and that the user will suffer depression as an independent issue.

The study also revealed that those who had given up tobacco more than a decade previously have less of a probability of developing depression than those who have never smoked; an increase in tobacco use was also correlated with a lessening of physical activity in the smoker's free time.

Experts say 50% of all smokers will eventually be killed by their addiction, 25% in middle age.