Impact of a Caffeine Restriction Policy on Inpatients With Schizophrenia

Caffeine is the most commonly used psychostimulant worldwide. Although its large intake is suspected to worsen psychotic symptoms because of increasing dopamine neurotransmission, schizophrenic patients are heavier caffeine consumers than the general population. This study aims to assess the impact of a caffeine restriction policy in a psychiatric hospital on patient psychopathology, hospitalization characteristics, and psychotropic prescribing patterns.It is a retrospective cross-sectional study based on electronic health records of a psychiatric hospital in the French-speaking area of Belgium. Two different periods were compared, the first (n = 142), in 2017, when caffeine was available in the institution and the second (n = 119), between November 2018 and November 2019 after the restriction of access to caffeine was implemented. Adult inpatients with schizophrenia or schizoaffective disorder admitted for an acute hospitalization were included. Antipsychotic exposure, benzodiazepine daily dose, Global Assessment of Functioning scores, length of hospital stay, and some other factors were tested for their potential association with the decaffeinated period.After adjusting for potential confounders, reduced caffeine availability inside the hospital was significantly associated with higher Global Assessment of Functioning scores at discharge (adjusted odds ratio [aOR] = 2.86, 95% confidence interval [CI] = 1.77-4.62) and shorter hospital stays (aOR = 0.68, 95% CI = 0.47-0.99) but was not associated with change in antipsychotic exposure at discharge (aOR = 1.04, 95% CI = 0.64-1.7) or benzodiazepine daily dose (aOR = 0.89, 95% CI = 0.61-1.29).Limiting access to caffeine in psychiatric hospitals is a simple and inexpensive intervention that should be promoted, especially for patients with schizophrenia.