Regular caffeine intake in patients with schizophrenia: Cognition and symptomatology

Individuals with schizophrenia use more caffeine than the general population. This study investigated the impact of caffeine on cognition and symptomatology in individuals with schizophrenia. A cross-sectional study was undertaken with 27 outpatients diagnosed with either schizophrenia or schizoaffective disorder. Participants were divided into two caffeine groups: moderate caffeine users (≤ 250 mg/day; N=13) and high caffeine users (>250 mg/day; N=14). Participants were then compared on measures of cognitive functioning, including processing speed, executive function, working memory, sustained attention, visual learning and memory, and verbal learning and memory. Symptomatology was also compared between the two caffeine groups, including positive, negative, and cognitive symptoms. The results showed that moderate caffeine users, compared to high caffeine users, demonstrated better performance on a task measuring executive function. While high caffeine users had fewer negative symptoms, they had more positive symptoms than moderate caffeine users. Nicotine dependence did not alter these findings. No other differences were discovered. In conclusion, our data suggests that moderate caffeine doses, rather than high caffeine doses, may be beneficial to executive function performance in patients with schizophrenia. Our results also suggest that while high caffeine users may be experiencing fewer negative symptoms compared to moderate caffeine users, they should also be aware of the potential increase in positive symptoms. Future research should continue to investigate the impact of caffeine on individuals with schizophrenia, including its possible therapeutic effects.