Psychotic symptoms following consumption of energy drinks: a systematic review

INTRODUCTION: Energy drinks (EDs) is an umbrella term for a family of beverages which contain high dosages of caffeine. ED consumption is increasing worldwide, and it is possible that excess ED consumption can cause or worsen symptoms of severe mental disorders (SMD) such as schizophrenia and bipolar affective disorder.

METHODS: We searched three electronic databases for studies on patients with SMD who had experienced psychotic symptoms following the consumption of energy drinks, as well as patients who developed psychotic symptoms after ED consumption without any prior severe psychiatric disorder. We conducted and reported this systematic review following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. We assessed the included case reports with the CARE criteria.

RESULTS: We included 11 publications, all of which were case reports. Two of these described two patients with a primary diagnosis of schizophrenia and three described six patients with a primary diagnosis of bipolar disorder. The remaining eight case reports described eight patients with no prior psychiatric diagnosis. All had experienced deterioration or onset of psychotic symptoms following intake of EDs.

DISCUSSION: ED use may be an emerging clinical challenge in psychiatry. However, it is also possible that EDs are simply a surrogate which indicate the occurrence of other factors associated with psychosis, such as male sex and poor socioeconomic status. Overall, limited research exists on the subject. Future research could aim at quantifying the use of EDs among psychiatric patients, and patients with SMH specifically.