"Smokers with Mental Illness Drink the Most Coffee"

US Study Results
Patients with Bipolar Disorder and Schizophrenia Have the Highest Intake
"Higher Risk of Health Deterioration"

A study has found that adults with mental illnesses who smoke consume the most caffeine in the United States.

Recently, China’s state-run Xinhua News Agency reported on a related paper published in the latest issue of the psychiatry academic journal Psychiatry Research.

Researchers from Rutgers University and the University of California, San Francisco analyzed data from 248 adult smokers. The participants included people with bipolar disorder, characterized by extreme mood swings, and schizophrenia, as well as a control group without psychiatric diagnoses.

The analysis showed that adult smokers with bipolar disorder consumed the most caffeine from sources such as coffee, followed by smokers with schizophrenia. Caffeine is a commonly used psychoactive substance in the U.S., known for its effects on alertness, concentration, and increased vigilance.

Jill Williams, director at Rutgers University, explained, “There are several theories regarding the relationship between caffeine intake and mental illness.”

One theory is that smokers with mental illnesses smoke two to three times more than normal individuals, and when tar enters the body, caffeine metabolism is further increased. Simulations have shown that caffeine absorption is higher in such cases.

Additionally, caffeine’s stimulating effect works by blocking the action of neurotransmitters called adenosine receptors, and it is also suggested that people with mental illnesses consume more caffeine due to autonomic nervous system abnormalities.

Meanwhile, people with mental illnesses are also at the highest risk of worsening health conditions if they consume excessive caffeine. The researchers stated, “Consuming more than 600 mg of caffeine can cause insomnia, anxiety, excessive stomach acid, heartburn, and chest pain.”

The maximum daily caffeine intake set by the Ministry of Food and Drug Safety is 400 mg for adults, 300 mg for pregnant women, and 2.5 mg per kilogram of body weight for adolescents. A caffeine intake of 400 mg corresponds to about three Americanos from a typical coffee shop.