LONDON (AFP) – People who drink more than seven cups of coffee a day tend to hallucinate more than less caffeine-driven colleagues, according to a study published Wednesday.
Those with a high caffeine intake are three times more likely to have heard a non-existent person’s voice than those who drink one cup a day, said the research by psychologists at Durham University.
But the study noted that the tendency to hear voices or have other hallucinations may not be caused by caffeine, but simply reflect the kind of people who drink lots of coffee.
“This is a first step towards looking at the wider factors associated with hallucinations,” said Simon Jones, the PhD student who led the study.
“Previous research has highlighted a number of important factors, such as childhood trauma. Many such factors are thought to be linked to hallucinations, in part because of their impact on the body’s reaction to stress.”
Co-author Charles Fernyhough stressed that the study did not confirm a causal link between caffeine intake and hallucinations, noting also that three percent of people regularly hear voices in their head.
“One interpretation may be that those students who were more prone to hallucinations used caffeine to help cope with their experiences,” he said.
“More work is needed to establish whether caffeine consumption, and nutrition in general, has an impact on those kinds of hallucination that cause distress.”
The researchers now plan to study the impact of other forms of food and drink on hallucinations.
“It’s surprising that there has been so little research into nutrition and hallucinations. In some countries high consumption levels of sugar and saturated fat are linked to poor mental health outcomes,” said Jones.
“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.”
The study appears in the journal Personality and Individual Differences.