If you’re stressed out and hopped up on caffeine — and who isn’t these days — you might be prone to hallucinating, namely hearing snatches of the tune “White Christmas” in white noise, according to a recent study by Australian researchers.
Scientists from La Trobe University said they found that people who were self-proclaimed stressed-out caffeine junkies (reporting that they consumed at least five caffeinated beverages, including coffee, a day) were more likely than people who said they were neither stressed nor heavy caffeine users to believe they heard bits of music (Bing Crosby’s “White Christmas”) in what was actually pure white noise played through headphones for three minutes.
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But lest panic brew among the legions of coffee-lovers out there, consider that the study had some serious limitations: for starters, it included just 92 participants and was not well controlled; both the “caffeine” and “stress” conditions were self-reported and not induced in the lab. It also didn’t measure actual psychotic hallucinations of any kind — only the likelihood of people hearing something the researchers explicitly suggested they might. Further, if the actual effect of participants’ caffeine intake had been mediated by factors like their age, weight, habitual usage, smoking status or pregnancy, the researchers didn’t control for that; neither were any formal mental health assessments of the participants conducted.
That being said, the findings are consistent with some previous research, according to Dr. Daniel Evatt, a postdoctoral research fellow in the department of psychiatry at Johns Hopkins University School of Medicine, who was not affiliated with the study. In 2009, a survey found that people who drank the equivalent of three or more cups of brewed coffee a day were three times more likely than others to report hearing and seeing things that didn’t exist.
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Also, the Los Angeles Times’ Booster Shots blog reported:
In 1992, the American Journal of Psychiatry published a report of “olfactory hallucination after intravenous caffeine.” The full report doesn’t seem to be available online, but the title alone should be enough to make you think twice about hooking yourself up to a latte IV.
Nevertheless, Evatt cautions not to conclude from the current study that caffeine use is generally associated with auditory hallucinations. “For someone to consume a lot of caffeine and experience hallucinations as a side effect is extremely rare,” he says. “This study is looking more at the processes and using caffeine as a way to understand the processes.”
He says these results, which could be replicated with other stimulants like energy drinks, would more likely occur in participants who are already predisposed to having hallucinations.
“These are interesting initial findings that indicate that stress and a stimulant like caffeine might interact to produce hallucination-like symptoms in some people, but the great majority of the world uses caffeine everyday,” he says. “If people were having full-blown hallucinations regularly, we would know about it.”
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The study was published in the minor journal Personality and Individual Differences.