Abstract
INTRODUCTION: Caffeine is the most consumed psychostimulant worldwide. Schizophrenia is an uncommon mental disorder affecting 0.34% of the global population. The aim of the current study was to investigate a possible association between caffeine consumption and symptom profile, dangerous behavior, and cognitive functions in patients with schizophrenia. METHODS: This prospective cohort study included consecutive patients diagnosed with schizophrenia who were admitted to the psychiatry ward or visited the psychiatry outpatient clinics at a tertiary University Hospital in Greece for a period of 12 months. All patients underwent an extensive psychiatric and cognitive function assessment using the standardized Greek version of the Positive and Negative Symptom Scale (PANSS), the generalized anxiety disorder scale (GAD-7), and the Addenbrooke cognitive test (ACE-R). RESULTS: In total, 53 patients were included in the present study. Mean age of the participants was 45 ± 11 years. The mean age at onset was 23 ± 7 years, while mean duration of illness from age of onset was 21.58 years. Caffeine serum levels exhibited a positive correlation with the poor attention component of the general psychopathology PANSS subscale, as well as with the attention and orientation component in the ACE-R. Moreover, another positive correlation was observed between the perilous behavior PANSS subscale and caffeine serum levels. Conversely as caffeine serum levels increased, fewer negative symptoms were reported, specifically, the poor rapport and passive/apathetic social withdrawal of the negative PANSS subscale. CONCLUSIONS: In summary, this study highlights the significant associations between caffeine serum levels, symptom severity, and cognition among patients with schizophrenia. While the findings provide valuable insights, they should be interpreted with caution due to the study's several limitations. More larger scale cohort studies are needed in order to elucidate the impact of caffeine consumption in patients with schizophrenia.