Do You Hallucinate with Those Double-Shot Espresso Extreme Energy Fusion Vente Jolts?

In the stress-diathesis model of schizophrenia, vulnerability to psychotic experiences depends on both environmental stressors and innate, presumably biological, factors. Although sustained use of large quantities of stimulants like amphetamines can routinely induce psychotic symptoms in healthy nonpsychotic individuals, few people indulge to that extent. However, many consume considerable quantities of caffeine. To assess whether typical consumption levels of caffeine can induce auditory hallucinations, investigators studied 92 community-recruited individuals free of psychiatric or neurological history, psychotropic medication use, or auditory impairment.

Participants were grouped by self-ratings of life-stress levels during the previous year and average daily caffeine consumption. After listening to the song “White Christmas” via external speakers in the laboratory, they were asked to listen via earphones to 3 minutes of white noise and to record the number of times, if any, that they heard embedded song fragments (called false alarms, as none were actually played). Compared with false alarms in participants with low stress and caffeine intake, these auditory hallucinations had small effect sizes among 27 individuals with high stress alone and 14 with high caffeine intake (>5 standard caffeinated drinks daily; approximately 200 mg) alone but had a high effect size among 16 individuals reporting both high stress and high caffeine intake. These associations remained significant after accounting for age, social desirability, mental imagery type, hallucinatory proneness, and creativity ratings.