Smoking not only endangers physical health, but also increases the risk of mental illness and, according to the latest research, can even trigger depression and bipolar disorder.
A new study involving professionals from the University of Saskatchewan looked at how genetics and smoking contribute to hospital admissions for major depression, bipolar disorder and schizophrenia. The results have been published in the English-language journal Acta Psychiatrica Scandinavica.
Association between smoking and mental disorders
While various research has already pointed to a strong link between smoking and mental illness, it has been unclear whether smoking causes depression and other mental disorders, or whether people smoke because they need to relieve the symptoms of a latent mental disorder, the team reports.
Data from 350,000 participants analyzed
To clarify this, the frog ends analyzed the health data of 350,000 people from the UK Biobank, one of the world’s largest databases of human health information.
The experts identified various recurring genetic variants among smoking participants. It was found that genes have a significant influence on whether people smoke or not.
Smoking is often genetically predisposed
“By looking at studies of twins, where the twins had the same genes but grew up in separate households, we were able to see that their genes can explain 43 percent of the risk of becoming a smoker,” study author Doug Speed said in a press release.
“There are a number of genetic variants that we can call smoking-related genes. The people in the data set who carried these genes but did not smoke had a lower risk of developing mental disorders compared to the smokers who carried these genes,” adds Speed.
Risk of mental illness from smoking
Smoking therefore increases the risk of developing mental disorders. “While not the only cause, smoking increases the risk of being hospitalized with a mental illness by 250 percent,” adds the expert.
Statistically, smoking increases the likelihood of mental disorders such as depression, bipolar disorder and schizophrenia. However, the mechanism by which smoking causes mental disorders remains unclear.
“One theory is that nicotine inhibits the uptake of the neurotransmitter serotonin in the brain, and we know that people with depression don’t produce enough serotonin. Another explanation could be that smoking causes inflammation in the brain, which in the long term can damage parts of the brain and lead to various mental disorders,” explains Speed. (as)