man smokingA new observational research study discovers a strong relationship between smoking and depression and that the risk of depression (and tobacco use) is tied to genetic and environmental influences.

In the investigation, scientists from the University of Navarra, in collaboration with the University of Las Palmas de Gran Canaria and the Harvard School of Public Health (USA) followed 8,556 subjects to determine the relationship between tobacco use and depression.

They found the risk of suffering depression increases 41 percent in smokers, in comparison with non-smokers.

The article, whose first author is Prof. Almudena Sánchez-Villegas, is based on research undertaken over the course of 6 years on university graduates with an average age of 42.

“Over the course of the tracking and data collection stage, 190 smokers who initially did not present depression were diagnosed with this disease by a doctor. In addition, 65 who were not diagnosed indicated that they were taking antidepressants during this period,” indicated Miguel Ángel Martínez-González, director of the research project and Chair Professor of the Department of Preventive Medicine and Public Health.

Among the mechanisms that shed light on this relationship, he points to “genetic and/or environmental disposition, which will increase the probability that the tobacco habit is retained and that the user will suffer depression as an independent issue.”

Lessening of Physical Activity

Investigators found an increase in tobacco use was correlated with a lessening of physical activity in the smoker’s free time. A finding that will benefit from additional research to ascertain directionality of the exposure.

Another interesting finding was that those who had given up tobacco more than a decade previously had a lesser probability of developing depression than those who never smoked.

In summary, researchers conclude that additional studies are indicated to clarify and determine the mechanisms that cause the associations as well as potential interventions to mitigate the risk of depression.

Source: University of Navarra