High Caffeine Intake Linked To Hallucination Proneness

[Richard D]

High caffeine consumption could be linked to a greater tendency to hallucinate, a new research study suggests.

People with a higher caffeine intake, from sources such as coffee, tea and caffeinated energy drinks, are more likely to report hallucinatory experiences such as hearing voices and seeing things that are not there, according to the Durham University study.

‘High caffeine users’ – those who consumed more than the equivalent of seven cups of instant coffee a day - were three times more likely to have heard a person’s voice when there was no one there compared with ‘low caffeine users’ who consumed less than the equivalent of one cup of instant coffee a day. With ninety per cent of North Americans consuming some of form caffeine every day, it is the world's most widely used drug.

The researchers say the findings will contribute to the beginnings of a better understanding of the effect of nutrition on hallucinations. Changes in food and drink consumption, including caffeine intake, could place people in a better position to cope with hallucinations or possibly impact on how frequently they occur, say the scientists.

http://www.sciencedaily.com/releases/2009/01/090113203901.htm

[Jamastiene]

1. Hey!

Just because I see unicorns and beautiful women in the trees in my backyard doesn't mean I drink too much Dr Pepper. :P

[Richard D]

2. hmmmm. . . .

. . . maybe I don't drink enough!

[MADem]

3. I only have two cups in the morning. But do I enjoy them. NT

[Sebastian Doyle]

4. Well that would explain Michael Weiner Savage, I guess.

You knew he had to be on something. Maybe it's just that "Rockstar" swill that his son sells?

[cliffordu]

5. So If I switch to decaf my cat will stop telling me to expose myself to the neighbors?

[Historic NY]

6. Interesting so that little voice is.....

:donut: Well I'm filling up now.

[Enthusiast]

7. This is as ridiculous

as the third hand smoke claims.

[uppityperson]

8. Anecdotal "study" done by asking 200 students questions=poor study.Correlation doesn't = causation.

"In the study, funded by the Economic and Social Research Council and the Medical Research Council, 200 students were asked about their typical intake of caffeine containing products, such as coffee, tea and energy drinks as well as chocolate bars and caffeine tablets. Their proneness to hallucinatory experiences, and their stress levels, were also assessed. Seeing things that were not there, hearing voices, and sensing the presence of dead people were amongst the experiences reported by some of the participants."

Just because these 200 students may have had a correlation, that does not = causation either.

Maybe they drink a lot of coffee because they hear voices, or see things, or are sleep deprived? Maybe? Students sleep deprived? You think that might be a possibility?

Poor "study".

[cosmik debris]

9. But if you are looking for something to confirm your bias....

No point on wasting time on real research.

Maybe they should have done the "study" at an AA meeting. :)

Lots of coffee there, and plenty of hallucination anecdotes too I'll bet.

[conscious evolution]

12. NA would be a better bet.

[cletustakethewheel]

18. Why is that? Because people who are trying to better themselves by quitting booze

are delusional?

Wow, just wow...

[cosmik debris]

19. Buh Bye! n/t

[hedgehog]

10. On the other hand, maybe that much caffeine in and of itself causes sleep deprivation!

You're right though, that this is more a suggestion of what should be studied rather than an definitive study.

[mopinko]

11. do you suppose they asked them about

their intake of, oh, marijuana, magic mushrooms, or......?

[salvorhardin]

13. Ben Goldacre has weighed in on this study

As usual he's provided a cogent and thorough analysis. Frankly, I agree with him that this is both a case of bad media reportage of science and a less than stellar study.

Aside from the fact that this is an observational study, with unexamined confounders, the correlation is actually quite weak. Quoting Ben Goldacre:

Then if you read the academic paper you find that the associations reported are weak. For the benefit of those who understand “regression” (and it makes anybody’s head hurt), 18% of the variance in the LSHS score is explained by gender, age and stress. When you add in caffeine to those three things, 21% of the variance in the LSHS score is explained: only an extra 3%, so caffeine adds very little. The finding is statistically significant, as the researchers point out, so its unlikely to be due to chance, but that doesn’t affect the fact that it’s still weak, it explains only a tiny amount of the overall variance in scores on the “predisposed-to-hallucinations” scale.
http://www.badscience.net/2009/01/drink-coffee-see-dead-people

So while there was a statistically significant correlation between those who reported high caffeine consumption and those who scored high on the Launay-Slade Hallucination Scale (LSHS), it was a relatively weak one. It's also important to remember that the study group was only 219 college students who filled out a survey. It was a small, self-selected cohort and we have no way of knowing if they are representative of the general population.

Also, the researchers apparently drove the media reporting by putting an unfounded figure into their press release:

Lastly, most newspapers reported a rather dramatic claim, that 7 cups of coffee a day is associated with a three times higher prevalence of hallucinations. This figure does not appear anywhere in the paper. It seems to be an ad hoc analysis done afterwards by the researchers, and put into the press release, so you cannot tell you how they did it, or whether they controlled appropriately for problems in the data, like something called “multiple comparisons“.

Here is the problem. Apparently this 3 times greater risk is for the top 10% of caffeine consumers, compared with the bottom 10%. They say that heavy caffeine drinkers were three times more likely to have answered affirmatively to just one LSHS question: “In the past, I have had the experience of hearing a person’s voice and then found that noone was there”.

Ben Goldacre quite rightly points out that this is likely a case of the Texas Sharpshooter Fallacy. We don't know why the researchers chose 10% as their magic number. Perhaps their reasoning is justified, perhaps not. We don't know though because they didn't put it in the paper. Again, Goldacre is correct in judging this to be a subversion of the peer-review process. It's science by press-release.

[Celebration]

14. studies on caffeine are really interesting

I tend to think there are more positives to caffeine ingestion than negatives. It's probably a very individual thing. I can't prove it, but I do think that people can be self medicating with caffeine. I think I read that people with schizophrenia do this sometimes, and that could account for the "voices" thing.

My guess is that most people have thought they heard a "voice" but noone was there (???) I don't know--that sounds normal to me--just a once in a while misinterpretation of background noise.

Thanks for deconstructing the study!

[salvorhardin]

15. Actually, that's Ben Goldacre's deconstruction

I was just summarizing.

However, you are right that, for most people, occasionally hearing a voice that isn't there is completely normal. That's why the ad hoc analysis by the researchers mentioned in the press release (and picked up on by the media) is rubbish.

In my opinion, this is one of the biggest lessons to be taken from modern cognitive psychology and neuroscience. Our brains, perceptual systems and senses are faulty and they are faulty in a way that predisposes us to Type 1 errors. The problem arises when we jump to supernatural explanations for our faulty perceptions and thinking or when we fail to control for the possibility that we are in error. As soon as we stop asking ourselves, "But is that really true?" then we have a problem.

That's why peer reviewed science is so successful. Science and the peer review process can be subverted, and are frequently. Over the long run though, science is self-correcting and studies like this one either fall to the wayside or further research is done to refine the theory. It might take longer than we're comfortable with, but it does happen.

As far as whether people are self-medicating with caffeine... Maybe. But not all. In fact, the vast majority of drug users are not self-medicating. They use a drug because it makes them feel good. Not because they're addicted, but because they want to alter their state of consciousness to feel better. In other words, it's recreational. There are cultural and sociological aspects to consider too. But to consider most, or even many, drug users as self-medicating carries the presumption that there is something medically wrong with them in the first place. That's a dangerous assumption to make I think, and not altogether different than the assumptions made by drug warriors.

[Celebration]

17. Self medicating is fine with me--it's the best way to medicate

People SHOULD self medicate. We hit big problems when people (like doctors) only go by the average responses to drugs in studies, and don't take into account individual variations in responses. For one person, caffeine is a great drug, and for another, it is a disaster. It is a great drug (yes, drug) for me, and a disaster for one of my daughters. The same thing happens with prescription drugs--great for one person, disaster for another, even given the same condition.

A drug doesn't have to be addictive to be a drug. It just has to have an effect of some sort. Caffeine definitely affects people.

I just can't imagine that there are people that haven't heard voices, by this definition. Some people might not want to admit it (???). And those people might not want to admit how much coffee they drink, either, LOL.

[uppityperson]

16. Had a person tell me I was "twitchy" due to my cup of coffee a day.

Turned out I was severely hyperthyroidic. Ah well, good thing I didn't let her try to heal my twitches by "energy work". Seems best to be open to more than your pet theory.