When people with schizophrenia smoke, they might be self-medicating without even realizing it, and future treatments for the mental illness may be modeled after cigarettes.

An international team of scientists says it may be able to explain why so many schizophrenics are heavy smokers — the addictive nicotine in cigarettes is boosting an area of their brains that becomes sluggish due to their illness. The researchers also suggest a particular genetic mutation has been found to cause that sluggish activity, which can occur in other mental conditions as well. A study in Nature Medicine says the findings may guide future drug developments.

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The root of their experiment was something called hypofrontality, which is decreased activity in the brain’s prefrontal cortex that leads to cognitive issues like troubles with memory and decision-making. By studying mice, the scientists from Institut Pasteur in Paris and from the University of Colorado at Boulder showed that the CHRNA5 genetic mutation, previously linked to a greater risk of schizophrenia, is also linked to that decreased function in the frontal lobe, the University of Colorado said in a statement. They also say nicotine reverses this problem, at least in the mice, because the addictive chemical acts on “receptors in regions of the brain key to healthy cognitive function.”

When mice with schizophrenic characteristics were given nicotine daily, their sluggish brain activity increased within two days,” the university noted. “Within one week it had normalized.”

The fact that consistently consuming nicotine neutralizes the hypofrontality is good news for doctors who are looking for new ways to improve brain function in people with schizophrenia. “Administration of nicotine may represent a therapeutic strategy for the treatment of schizophrenia,” the study says, adding that it also explains why those patients tend to smoke heavily.

According to the university statement, between 80 and 90 percent of schizophrenics smoke, and potential treatments could be “non-addictive [and] nicotine-based.”

The benefits of the findings extend beyond just schizophrenia — hypofrontality is an issue in other mental health issues like addiction and bipolar disorder.

“Basically the nicotine is compensating for a genetically determined impairment,” Jerry Stitzel, a researcher from Boulder said in his university’s statement.

Source: Maskos U, Koukouli F, Rooy M, et al. Nicotine reverses hypofrontality in animal models of addiction and schizophrenia. Nature Medicine. 2017.

See also:

Schizophrenic Brains Are Rusting

Why Schizophrenia Makes You Hallucinate