Voices in your head? Cut back on the coffee

Jan 14 2009 by Tony Henderson, The Journal

DOWNING seven cups of coffee a day could leave you hallucinating and hearing voices. Durham University researchers carried out a study of people with high caffeine intakes to find out how big doses of the chemical affected the brain.

And they concluded heavy coffee drinkers who down up to seven cups of instant could be prone to hallucinations.

Their study, which also included tea and caffeinated energy drinks, found people with high intakes were three times more likely to have heard a person’s voice when there was no one there compared with people who consumed less than the equivalent of one cup of instant coffee a day.

The researchers said the findings would contribute to the beginnings of a better understanding of the effect of nutrition on hallucinations.

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. The likelihood of them having hallucinatory experiences was then assessed, alongside their stress levels.

Seeing things that were not there, hearing voices and sensing the presence of dead people were among the experiences reported by some of the participants.

The researchers said their findings could be down to the fact that caffeine has been found to exacerbate the physiological effects of pressure. When under stress, the body releases a hormone called cortisol. More of this stress hormone is released in response to stress when people have recently had caffeine.

It is this extra boost of cortisol which may link caffeine intake with an increased tendency to hallucinate, said the scientists.

Lead author, Simon Jones, a PhD student at Durham University’s Psychology Department, said: “This is a first step towards looking at the wider factors associated with hallucinations.

“Previous research has highlighted a number of important factors, such as childhood trauma, which may lead to clinically relevant hallucinations. Many such factors are thought to be linked to hallucinations in part because of their impact on the body’s reaction to stress. Given the link between food and mood, and particularly between caffeine and the body’s response to stress, it seems sensible to examine what a nutritional perspective may add.”

Mr Jones said hallucinations were not necessarily a sign of mental illness. He said: “Most people will have had brief experiences of hearing voices when there is no one there.”