Americans are drinking more caffeinated beverages than ever before, but Rutgers researchers have found one group that tops the caffeine consumption charts: adult smokers with mental illness.
In a study published online ahead of print in the January issue of the journal Psychiatric researchJill M. Williams, director of the division of addiction psychiatry at Rutgers Robert Wood Johnson Medical School, found that adult smokers with bipolar disorder and schizophrenia not only drink the most caffeine, but also run the greater risk of negative health consequences.
“Caffeine is generally considered safe and even has some health benefits,” Williams said. “But we just don’t understand the cognitive and psychiatric effects of high caffeine intake, especially in smokers with mental illness.”
Caffeine is one of the most widely used psychoactive drugs in the United States, with the main effects being increased alertness, alertness, and alertness. Although it is considered safe for most healthy adults to consume up to 400 milligrams of caffeine per day – the equivalent of about four cups of brewed coffee – consuming more than 600 milligrams is not recommended. and can lead to anxiety, insomnia, excess stomach acid and heartburn.
Little is known about caffeine’s influence on executive functions, such as reasoning and decision-making, and the studies that have been done have mostly included healthy adults without mental illness, Williams said. Even less is known about the impact of high caffeine intake on psychiatric symptoms or sleep in adults with severe mental illness who smoke.
To fill in those gaps, Williams and colleagues from Rutgers Psychology Department and University of California San Francisco School of Medicine analyzed data from 248 adult smokers recruited in a previous study. The participants were either outpatient smokers with schizophrenia or bipolar disorder, or from a control group without a psychiatric diagnosis. All participants were one-pack daily smokers.
At the start of the study, participants completed surveys about smoking history, caffeine consumption, physical health, and psychological symptoms. The researchers also took blood samples to measure serum caffeine levels.
They found that caffeine consumption was highest in participants with bipolar disorder, followed by adults with schizophrenia. The control group consumed the least caffeine.
Williams said there are several theories to explain the relationship between caffeine consumption and mental illness. One is a well-established association between caffeine and smoking: people with mental illnesses smoke at rates two to three times higher than the general population, and since the tars in cigarette smoke increase the metabolism of caffeine, more caffeine is needed to achieve stimulating effects. .
Another theory links high caffeine intake to adenosine receptors and supports a possible self-medication effect in people with mental illness, Williams said. People with mental illnesses also appear to be vulnerable to all types of addictive substances, putting them at higher risk for excessive use and more negative consequences. Additionally, researchers have found evidence that mood is linked to caffeine consumption, particularly low mood.
Each of these explanations deserves further investigation, Williams said.
“People today consume massive amounts of caffeine in more concentrated forms — like energy drinks or double shots of espresso — far more than when our participants were surveyed,” she said. “And yet, the effects of high caffeine intake remain vastly understudied. This is especially true for people with mental illness.
The title of the article
Caffeine levels and dietary intake in smokers with schizophrenia and bipolar disorder
Publication date of articles
Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of press releases posted on EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.