Smoking can increase the risk of mental health problems such as depression and schizophrenia, according to a new report.
There has long been a link between smoking and mental health conditions, but it hasn’t been clear if smoking causes problems or is just more popular among those with poor mental health, says The Guardian.
But now scientists from the University of Bristol say they have discovered “causal effects in both directions”.
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How did the study link smoking and mental health?
The study, published in the journal of Psychological Medicine, found evidence that smoking causes mental health issues, and that those with mental health issues are more likely to start smoking, says ITV.
Researchers analysed data from 462,690 people with European ancestry, examining whether those with schizophrenia and depression had genetic variants linked to the likelihood of a person starting smoking.
The results showed that both starting smoking and higher levels of smoking were linked to a greater likelihood of having a genetic predisposition to mental health issues.
Those with a genetic predisposition towards depression and schizophrenia were also found to be more likely to start smoking, and to smoke more.
What do the study’s authors say?
Dr Robyn Wootton, the first author of the research, said that the study showed the importance of preventing smoking to protect people’s mental health, on top of the more widely-known serious physical consequences.
“Of course, if [smoking] is also making the risk of mental illness worse, then we should be helping individuals who have existing mental health problems to stop as well,” she said.
Wootton said now causation is established, it is important to explore exactly how smoking increases the mental health risk.
She suggested that the way that nicotine influences pathways in the brain could be the link to mental health problems. That would be important if true, as nicotine is also found in e-cigarettes.
Marcus Munafo, professor of biological psychology in Bristol’s School of Psychological Science and senior author on the study, said: “The increasing availability of genetic data in large studies… can tell us as much about environmental influences – in this case the effects of smoking on mental health – as about underlying biology.”
What can you do to avoid problems?
Not smoking is a good place to start, and it might help you avoid a variety of other grisly physical issues.
Dr Ian Hamilton, an expert in addiction and mental health from the University of York, said of the new study: “While the physical harms of smoking are well known, this research points to the mental health risks of using tobacco. This risk should be communicated widely but particularly to school-age children who might be tempted to try smoking.”
Bristol University’s research is backed up by another new report from public health charity Action on Smoking and Health (ASH), which found that smoking is the biggest contributor to an average 10-20 year reduction in life expectancy among people with mental health conditions.
ASH also found that people with serious mental health conditions are 50% more likely to smoke than the general population.
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