Smoking may increase risk of depression, schizophrenia, study says

Where there’s smoke, there’s fire.

Smoking may increase a person’s risk of developing depression and schizophrenia, a new study says, increasing evidence of the effects of tobacco use on mental health.

The full study, published Wednesday in the journal Psychological Medicine, was led by researchers at the University of Bristol in England.

Authors noted in the study that previous research has assumed a relationship between mental health and smoking by the idea of self-medicating, or the thought that either symptoms of mental illness or side effects of medication for mental illness are alleviated by tobacco.

While smoking rates are generally higher in people with mental illness than those without, researchers set out to find out if it was due to a cause-and-effect relationship.

It is estimated that people with mental illness smoke two to four times the rate of the general population, according to the National Institute on Drug Abuse.

Through evaluating data of 462,690 individuals, researchers found that tobacco smoking increased the risk of mental illnesses including depression and schizophrenia, a statement said. The study also found that depression and schizophrenia increase the likelihood of smoking, but evidence was weaker in cases of schizophrenia.

“Individuals with mental illness are often overlooked in our efforts to reduce smoking prevalence, leading to health inequalities," Dr. Robyn Wootton, senior research associate at the University of Britsol’s School of Psychological Science said in a statement. Our work shows that we should be making every effort to prevent smoking initiation and encourage smoking cessation because of the consequences to mental health as well as physical health.”

Authors noted that the effects with depression and smoking were greater than that of schizophrenia in the study.

The study increases evidence of the overall effects of smoking on mental health. In September, another study published in The British Journal of Psychiatry found an increased risk of bipolar disorder with smoking.