Too Much Caffeine Can Trigger Hallucinations

MELBOURNE, AustraliaIndividuals who consume five or more cups of caffeinated coffee may increase their risk of auditory hallucinations, according to a new study published in the journal Personality and Individual Differences. The findings suggest stress, coupled with high caffeine consumption, trigger imaginary voices in the head.

Researchers at La Trobe Universitys School of Psychological Sciences studied the effect of caffeine and stress on 92 non-clinical participants who were assigned to either a high- or a low-stress condition and a high- or a low-caffeine condition on the basis of self-report. They were asked to listen to white noise and report each time they heard Bing Crosbys rendition of White Christmas" during the white noise (which was never played). Results indicated the interaction of stress and caffeine had a significant effect on the reported frequency of hearing the song. The participants with high levels of stress or consumed high levels of caffeine were more likely to hear the song.

High caffeine levels in association with high levels of stressful life events interacted to produce higher levels of hallucination in non-clinical participants, indication that further caution needs to be exercised with the use of this overtly safe drug," said lead author Professor Simon Crowe. There is a link between high levels of stress and psychosis, and caffeine was found to correlate with hallucination proneness. The combination of caffeine and stress affect the likelihood of an individual experiencing a psychosis-like symptom."

Crowe said the findings also helped explain the mechanism by which stress may facilitate the symptoms of schizophrenia in non-clinical samples.