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.
