Caffeine Linked to Hallucinations

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Did you hear that?

Um, nothing. Never mind. I meant to say, did you hear that consuming too much caffeine could make you more prone to "hallucinatory experiences?"

According to a study published this week in the journal Personality and Individual Differences, "high caffeine users"* are three times more likely to experience auditory hallucinations—hearing voices when no has actually spoken—than people who consume little or no caffeine.

How did they figure this out? Well, psychology researchers at Durham University in England surveyed 200 students about their eating and drinking habits, stress levels, and proneness to hallucinations. Many of the most highly caffeinated students reported experiences of "seeing things that were not there, hearing voices, and sensing the presence of dead people."

Well, caffeine is a drug, after all, but let's not start locking those lattes behind the counter just yet—the researchers were careful to note that this is only a link, not proof that caffeine causes the hallucinations in a direct sense. The real culprit could be cortisol, a hormone the body releases under stress. If that stress occurs when you have caffeine in your system, your body seems to self-prescribe a higher dosage of cortisol than normal.

And it could be a classic case of chicken and egg. I mean, if I was in college and started hearing voices late at night in the library, I would probably deduce that I needed to get some sleep. But say it was finals week, and sleep wasn't an option—I'd probably drink a lot of coffee. And if I thought there was a ghost in the room, I'm guessing I wouldn't be eager to turn the lights out at night.

In other words, which came first for these students, the caffeine or the hallucination-proneness?

 don't know, and neither do the psychologists, so it looks like there's a whole field of caffeinated consciousness yet to explore. Here's my research contribution: I surveyed a very, very small sample of the Smithsonian editors...okay, one...who drinks at least five cups of coffee a day (in the form of two 20-ouncers).

He said sorry, but no, he's never heard voices when there's no one there. Then he looked worried.

"Unless you're not really asking me this," he said. And reached for his coffee cup.

*The study defines high caffeine consumption as "more than the equivalent of seven cups of instant coffee a day," although it could be consumed in a form other than coffee (such as tea, energy drinks, chocolate, or even caffeine tablets).

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