Credit: CC0 Public Domain

Tobacco smokers are at increased risk of psychotic disorders such as schizophrenia, according to University of Queensland researchers.

Their review of eight long-running studies has found strong evidence of an association between smoking and mental illness, which they suggest is most likely caused by nicotine.

Associate Professor James Scott said the findings raised serious concerns about the increasing use of nicotine through e-cigarettes by young adults.

"People who smoke tobacco have an approximately twofold increased risk of developing schizophrenia or psychosis," Dr. Scott said.

"While e-cigarettes reduce some of the harms associated with smoking, governments need to consider their potential to harm the mental health of young people."

Dr. Scott said e-cigarettes were often reported to be safe, and marketing was directed towards young people.

"More research is urgently needed to examine the association between e-cigarette use and psychosis, particularly in adolescents and young adults," Dr. Scott said.

"Until there is a better understanding of the harm of e-cigarettes, it would be safest that liquid nicotine remains illegal to buy in Australia without a prescription."

The review is published in Frontiers in Psychiatry.

More information: James G. Scott et al. Evidence of a Causal Relationship Between Smoking Tobacco and Schizophrenia Spectrum Disorders, Frontiers in Psychiatry (2018). James G. Scott et al. Evidence of a Causal Relationship Between Smoking Tobacco and Schizophrenia Spectrum Disorders,(2018). DOI: 10.3389/fpsyt.2018.00607