By Dawson W. Hedges, MD, Fu Lye Woon, MA, and Scott P. Hoopes, MD
• Caffeine use can cause depression, anxiety, agitation, and aggression.
• Caffeine may cause psychosis that when chronic may mimic other psychiatric conditions.
• Caffeinism should be considered in the differential diagnosis of psychosis.
Dr. Hedges is an assistant professor in the Department of Psychology and the Neuroscience Center at Brigham Young University in Provo, Utah. Mr. Woon is a doctoral student in clinical psychology in the Department of Psychology and the Neuroscience Center at Brigham Young University. Dr. Hoopes is an adjunct faculty member in the Department of Psychiatry at the University of Utah School of Medicine and in private practice in Boise, Idaho.
Faculty Disclosures: The authors do not have an affiliation with or financial interest in an organization that might pose a conflict of interest.
Submitted for publication: November 1, 2008; Accepted for publication: February 23, 2009.
Please direct all correspondence to: Dawson W. Hedges, MD, 1001 SWKT, Brigham Young University, Department of Psychology and the Neuroscience Center, Provo, UT 84602; Tel: 801-422-6357, Fax: 801-422-0602; E-mail:
As a competitive adenosine antagonist, caffeine affects dopamine transmission and has been reported to worsen psychosis in people with schizophrenia and to cause psychosis in otherwise healthy people.
We report of case of apparent chronic caffeine-induced psychosis characterized by delusions and paranoia in a 47-year-old man with high caffeine intake. The psychosis resolved within 7 weeks after lowering caffeine intake without use of antipsychotic medication. Clinicians might consider the possibility of caffeinism when evaluating chronic psychosis.
A 47-year-old successful male farmer with no history of psychiatric hospitalization presented with a 7-year history of depression, diminished sleep to as little as 4 hours/night, poor energy, explosive anger, decreased concentration, decreased appetite, anhedonia, and feeling of worthlessness.
Seven years before his first presentation, the patient had developed the conviction that people were plotting against him to drive him off of his farm and take his land. At least twice, when he had found dead livestock on his farm, the patient thought that it was part of the plot against him and would entertain no other possibilities.
The patient interpreted tire tracks in the driveway as belonging to the car of individuals trying to take his land, even though other more plausible possibilities existed. According to the patient’s wife, the subject interpreted many everyday occurrences as evidence of the plot.
Convinced of a plot against him, he installed surveillance cameras in his house and on his farm but never caught anything that would support his conviction that as part of the plot people were coming onto his farm at night. He became so preoccupied with the alleged plot that he neglected the business of the farm and eventually declared bankruptcy as a result. His preoccupation with the plot also led him to neglect the upkeep of his home, and he had his children taken from him because of unsanitary living conditions.
In addition to psychosis, the patient reported life-long difficulty sustaining attention, excessive talking, disorganization, distraction, and forgetfulness. He denied other features of anxiety and psychosis.
The patient reported drinking less than one case of beer annually. However, ~7 years before presentation, he had sharply increased his consumption of coffee from 10– 12 cups/day to ~36 cups/day, a change in coffee consumption corroborated by his wife who made much of the coffee for him at home. There was no history of psychosis before the increase in coffee consumption, but after the increased consumption, the patient developed paranoia. At presentation, the patient reported drinking >1 gallon of coffee/day.