Withdrawal from long-term use of caffeinated drinks can cause schizophrenia-like symptoms: A case report.

Abstract

In recent years, energy drinks containing large amounts of caffeine have become popular among young people, and various health problems caused by caffeine have become a major issue.1 Caffeine stimulates the central nervous system and has been associated with some risk of dependence.2 We report on a male adolescent who presented with schizophrenia-like symptoms after abruptly ceasing long-term use of energy drinks. A 16-year-old Japanese boy with no history of manic/hypomanic, major depressive, or psychotic episodes reported perceiving ‘another self’ in his head. He had no history of illegal drug use or family history of psychiatric disorders. Some reports have described caffeine-induced psychotic symptoms,3 but to the best of our knowledge, no report has indicated the occurrence of psychotic symptoms during caffeine withdrawal. This is the first reported case of temporary psychosis-like symptoms during caffeine withdrawal. At age 14 years, the patient had developed a nightly practice of drawing and would use energy drinks to stay awake after midnight. His intake of energy drinks had gradually increased to 3550 mL per 24 h, equivalent to 1280 mg of caffeine per day. When he was in junior high, he had sometimes had the urge to kill someone, and, to distract himself from this urge, he had resorted to self-harm by injuring his own arm using a ballpoint pen. By age 16 years, his high school homeroom teacher had become concerned that he was drinking energy drinks too often and appearing lethargic during class. He was strongly persuaded to discontinue consuming energy drinks, and he stopped abruptly. For the next several days, he felt intense fatigue and had difficulty in concentrating. Ten days after ceasing energy-drink consumption, he began having thoughts of the ‘other self.’ This ‘other self’ ordered him to write down his conversations with it on a piece of paper. Four days later, during a class, he had an urge to kill someone. His body felt like it was being controlled by his ‘other self,’ and he actually picked up a knife; however, he thought better of it. He was scared and shaking, and consulted his health teacher. Hence, accompanied by a concerned teacher and his mother, he visited a psychiatrist at our hospital. At the first interview, however, the ‘voice’ had weakened and the urge to hurt others was gone. He was slightly fatigued during the daytime but no longer craved energy drinks. Brain computed tomography revealed no abnormalities. His score on the Wechsler Adult Intelligence Scale, 3rd edition, was 93, within normal range. In this case, long-term use of caffeine had been suddenly discontinued, and delusions had developed several days later. We tentatively diagnosed ‘caffeine-induced psychotic disorder, with onset during withdrawal,’ on the basis of the diagnostic criteria of the DSM-5. He did not take any antipsychotic drugs. The delusions gradually disappeared, and the patient regained a sense of self-control over his thoughts within 1 month. In the more than 2 years since, the symptoms have not recurred. The relationship between caffeine interruption and symptom appearance suggests a caffeine-related disorder rather than another diagnosis, such as a brief psychotic disorder. It is rare for schizophrenia-like symptoms to occur during caffeine withdrawal, and the exact mechanisms by which they do occur are unknown. Caffeine is a competitive antagonist of the adenosine receptor and is not directly involved in dopamine release in the nucleus accumbens, which plays a critical role in drug dependence; thus, symptoms of withdrawal from caffeine are generally considered mild and transient. However, results of a study in rats suggested that high doses (10 mg/kg) of caffeine may have the potential to activate the nucleus accumbens and prefrontal cortex4; therefore, psychiatric symptoms might occur when high caffeine intake is abruptly discontinued. If caffeine is a psychostimulant, psychotic symptoms may develop in the withdrawal phase because of a reverse tolerance phenomenon or flashback.5 In these cases, however, schizophrenia should also be considered part of the differential diagnosis. Many young people stay up late to study or play video games and then become sleep deprived. To stay awake, they may form a habit of consuming large quantities of caffeinated drinks.6 According to the US Department of Health and Human Services, the number of emergency 911 calls related to energy drink overdose doubled between 2007 and 2011.7 Energy drinks are readily available and are used inappropriately as ‘study drugs’; thus, dependency on caffeine is possible. Because of recent increases in the consumption of energy drinks, the inappropriate use of highly caffeinated beverages should be investigated closely. Signed releases from the patient and legal guardian authorizing publication have been obtained. The authors thank Enago (www.enago.jp) for the English-language review. The authors declare no conflict of interest.