Nicotine May Help Treat Schizophrenia, Study Finds

Smoking is notoriously bad for one’s health. Tobacco use can lead to disability, disease, and even death, but new research suggests that nicotine may have some benefits for patients living with schizophrenia. 

Schizophrenia is a severe and disabling mental condition that affects more than 21 million people globally and over 1% of the United States adult population every year.

A significant number of studies have shown the condition to be a brain disorder, with brain imaging techniques revealing that neurological impairment often accompanies schizophrenia.

One of the neurological abnormalities that former research has linked to schizophrenia is a decreased activity in the prefrontal cortex (PFC). This area hosts the brain’s executive functions, such as judgment, decision-making, and problem-solving. The PFC also helps us to stay in control during stressful events, and deals with short-term and long-term memory.

A new study, published in the journal Nature Medicine, suggests that nicotine may be able to help schizophrenia patients.

Researchers from University of Colorado (CU) Boulder - led by Uwe Maskos, a researcher at the Pasteur Institute in Paris, France - set out to understand the causes of “hypofrontality,” a decreased neuronal activation of the PFC when the task requires it, medicalnewstoday.com reported.

Hypofrontality is thought to cause many of the cognitive problems associated with schizophrenia, including difficulty making decisions, focusing, or remembering things.

Additionally, former research has linked schizophrenia to a mutation in the CHRNA5 gene.

Many previous studies have also found a link between schizophrenia, the CHRNA5 gene, and smoking. Nearly 90% of people with schizophrenia smoke, most of them being heavy smokers, and 60 to 70% of people with bipolar disorder also smoke.

Additionally, research has shown an association between the number of cigarettes smoked per day and a polymorphic variation of the CHRNA5 gene.

In this context, Maskos and team asked the question: does a variation in the CHRNA5 gene trigger hypofrontality? If so, how does that happen, and can nicotine do anything to stop this process?

The team examined mice that had the CHRNA5 gene and displayed neurocognitive behavioral impairment in social interaction and sensorimotor tasks.

Using brain imaging techniques, they found that the mice also had hypofrontality and decreased neural activity in a way that is similar to the hypofrontality found in patients with schizophrenia and addiction.

Researchers administered nicotine to the mice, which reversed the hypofrontality. By acting on nicotinic receptors in brain areas related to healthy cognitive function, chronic nicotine administration reversed the cognitive impairment.

The authors conclude that their findings reveal a physiological basis for why schizophrenia patients tend to self-medicate by smoking. They hope the findings will ultimately lead to non-addictive, nicotine-based therapies for patients with schizophrenia.