High caffeine consumption could be linked to a greater tendency to hallucinate. People with a higher caffeine intake from sources such as coffee, tea and caffeinated energy drinks are three times more likely to report hallucinatory experiences such as hearing voices and seeing things that are not there, than people with a low caffeine intake. 'High caffeine intake' was defined as more than the equivalent of seven cups of instant coffee a day, for the purposes of this study. Caffeine has been found to exacerbate the physiological effects of stress; researchers speculate that this extra boost of cortisol may be behind this increased tendency to hallucinate.
Durham University (2009, January 14). High caffeine intake linked to hallucination proneness. Durham University News & Events. Retrieved January 19, 2009, from http://www.dur.ac.uk/news/newsitem/?itemno=7403