Smoking Is Associated With An Increased Risk Of Schizophrenia And Severe Depression

Smoking is associated with an increased risk of schizophrenia and severe depression

Smoking cigarettes increases the risk of mental health problems such as depression and schizophrenia. Even for those asking to smoke, this risk persists after many years.

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Smoking cigarettes increases the risk of mental health problems such as depression and schizophrenia, a University of Bristol study published in Psychological Medicine found.

As you know, smoking is more common among people with mental disorders. However, it is unclear whether smoking can be a causative factor in these problems, or is simply a way to "self-medicate" for mental illness.

Researchers analyzed data from 462,690 people of European descent and identified gene variations associated with traits such as depression or schizophrenia. They then tested how often and for how long people with each of these gene variations smoke.

“We found evidence of causation in both directions,” said Robyn Wootton, lead author of the study.

Scientists compared the risk of depression or schizophrenia among people with a genetic predisposition to smoking and without it.

Using two separate, vast genetic databases of people with schizophrenia and people with severe depression, they investigated whether the risk of developing these conditions was related to a genetic predisposition to smoking.

The results show that both smoking initiation and higher smoking rates are associated with an increased risk of depression and schizophrenia. So, if you smoke 20 cigarettes a day for 15 years, and then quit and do not smoke for 17 years, the chances of developing schizophrenia more than double, and depression - almost double, compared to those who have never smoked …

The researchers also found that people with a genetic predisposition to depression or schizophrenia smoked more. But this connection was weaker than the inverse.

“People with mental illness are often overlooked in our fight to reduce smoking prevalence, leading to inequities in health. Our work demonstrates the need to make every effort to prevent smoking initiation and to encourage smoking cessation due to both mental and physical health consequences,”said Robin Wootton.

The study is limited because it was targeted at people of European descent. The authors point to the need to study in the future how exactly smoking can increase the risk of schizophrenia and depression. One hypothesis is that nicotine affects the pathways in the brain associated with mental health problems. This can be important because e-cigarettes also contain nicotine.

“While the physical harm from smoking is well known, this study points to the mental health risks of tobacco use. This risk should be widely publicized, especially for school-aged children who may be tempted to try smoking,”summed up Ian Hamilton, an expert on substance abuse and mental health at the University of York.