Researchers from Durham University in the UK have revealed that people who drink more than seven cups of instant coffee a day have a greater tendency to hallucinate, often hearing voices and sensing non-existent people.
Researchers studied 200 students who were asked about their usual intake of caffeine products, with those who had a high intake being three times more likely to have heard the voice of someone non-existent than users who consumed much less.
Caffeine can also be obtained from tea, chocolate, pep pills and energy drinks.
According to the study, hallucinations are not necessarily a sign of mental illness, with around three per cent of people regularly hearing voices.
