Smoking can lead to health conditions such as lung cancer, heart attacks and even stroke. But can cigarette smoking affect mental health too? A new study suggests that smoking doubles the risk of mental health issues such as depression and bipolar disorder.
In the latest study published in the journal Acta Psychiatrica Scandinavica, researchers from Aarhus University evaluated 337,140 participants from the U.K. Biobank to understand the relationship between smoking and mental illness.
“The numbers speak for themselves. Smoking does cause mental illness. Although it’s not the only cause, smoking increases the risk of being hospitalized with a mental illness by 250%,” Doug Speed, a co-author of the study, said in a news release.
“Smoking typically comes before the mental illness. In fact, a long time before. On average, people from the data set began smoking at the age of 17, while they were typically not admitted to hospital with a mental disorder until after the age of 30,” he added.
Researchers found the chances of a child becoming a smoker were high when the adoptive parents smoked. However, the risk was higher when the biological parents smoked. The team found that “smoking-related genes” inherited from the biological parents play a crucial role in deciding if a person will smoke.
“When we looked at the many smokers in the database, we found a number of recurring genetic variants. By looking at twin studies, in which the twins had the same genes but grew up in separate homes, we could see that their genes could explain 43% of the risk of becoming a smoker,” Speed said.
The study did not evaluate the biological mechanism by which smoking causes mental health issues. Researchers believe the issues might be due to the brain damage caused by nicotine.
“We still need to find the biological mechanism that causes smoking to induce mental disorders. One theory is that nicotine inhibits absorption of the neurotransmitter serotonin in the brain, and we know that people with depression don’t produce enough serotonin,” Speed said. “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. But as I said: We don’t know for sure as yet.”
Published by Medicaldaily.com