coffee cigarette
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Study Shows US Adult Smokers With Mental Health Issues Consume More Caffeine

A new study shows that although Americans are consuming more caffeine than ever, one group is surpassing all the others when it comes to their caffeine intake.

Smoking and caffeine combined

Although it is widely accepted that Americans drink a lot of caffeine-based beverages, those with mental health issues consume more than average, according to new research published by Rutgers University in the United States.

In a study published online, Jill M. Williams, director of the division of addiction psychiatry at Rutgers Robert Wood Johnson Medical School, found not only do adult smokers with bipolar disorder and schizophrenia drink the most caffeine, but they are also at the highest risk of suffering from negative health consequences.

Caffeine is one of the most widely used psychoactive drugs in the United States, with the main effects of increased alertness, attention, and vigilance.

While it’s 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 isn’t recommended. It can lead to anxiety, insomnia, excess stomach acid, and heartburn.

Speaking in regard to the research findings, Williams told Neuroscience Today,

“Caffeine is generally considered safe and even has some health benefits. But we just don’t understand the cognitive and psychiatric effects of high caffeine intake, especially among smokers with mental illness.”


What is the impact of more caffeine?

Little is known about caffeine’s influence on executive functions, such as reasoning and decision-making.  Studies that have been done have mostly included healthy adults without mental illness, according to Williams.

Even less is known about how high caffeine intake may impact psychiatric symptoms or sleep in adults with serious mental illnesses who smoke.

To address these gaps, Williams and her colleagues analyzed data from 248 adult smokers recruited during a previous study. Participants were either outpatient smokers with schizophrenia or bipolar disorder or from a control group with no psychiatric diagnoses. All participants were smoking at least one packet of cigarettes daily.

At the commencement of the study, participants completed surveys on smoking history, caffeine use, physical health, and psychological symptoms. The researchers also collected blood samples to measure serum caffeine levels.

Photo: via Pixabay


The relationship between caffeine and nicotine

They found caffeine intake was highest among participants with bipolar disorder, followed by adults with schizophrenia. The control group consumed the least amount of caffeine. Williams said there are several theories to explain the relationship between caffeine intake 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 because the tars in cigarette smoke increase the metabolism of caffeine, it takes more caffeine to achieve the stimulating effects that others experience with less.

Another theory links high caffeine intake to hormone receptors and supports the theory of a possible self-medication effect among people with mental illness. People with mental illnesses also seem to have vulnerabilities to all types of addictive substances, putting them at higher risk for excess intake and more negative consequences.

Additionally, the researchers found evidence that mood is linked to caffeine intake, especially bad moods.

Saying that each of these findings individually requires further investigation, Wiliams added,

“Today, people consume huge amounts of caffeine in more concentrated forms such as energy drinks or double shots of espresso. This is far more than when our participants were surveyed. And yet, the effects of high caffeine intake remain widely understudied. This is particularly true for people with mental illness.”


In summary

It is interesting to see research in this area confirm what many may have suspected over the years. In a society where smoking is on the decline as a whole, it is clear that society is finding other ways to receive the same ‘hit’ that tobacco once provided.

That said, for many with mental health conditions, this research shows that tobacco and caffeine combined remain a staple to provide a self-medicating effect to induce a feeling of calm – a feeling which appears to be unable to obtain through other means.

What do you think about the findings of this research? Do you turn to smoking or caffeine (or both) as a way to medicate your mental health? Let us know more in the comments.

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