Candadian researchers from the Center for Quantitative Genetics and Genomics of Aarhu published their findings regarding the link between smoking and depression.
The researchers accessed the UK Biobank, which is one of the largest databases of human health information and has genetic data of more than a half a million people. Along with this information, the researchers combined it with a lot of other health information and answers that the participants gave concerning their lifestyle.
The research team took into account that people typically start smoking before the age of 20 but generally aren't admitted into a hospital with mental illness until they are between the ages of 30 and 60, on average. In addition, the researchers noted that there is a genetic factor to becoming a smoker and referred to this as 'smoking-related genes'. Participants in the data set who carried the smoking-related genes but didn't smoke were less likely to develop mental disorders compared to those with the genes and smoked.
Researchers found that smoking raises the risk of being hospitalized with a mental illness by 250 percent. The biological mechanism that causes smoking to trigger mental disorders is still unknown.