No, it’s not what you think. We’re not talking of real dead people here. According to research, heavy coffee drinkers were three times more likely to hallucinate and feel that there are
dead people (which is also part of the hallucination process). High caffeine users were taking seven cups of coffee or more. Intake of more caffeine from coffee and other caffeine-rich substance like soda and tea increases the production of cortisol, a hormone produced during stress. High cortisol levels are linked to hallucinations, both visual and auditory.