A study by researchers at the University of São Paulo's Ribeirão Preto Medical School (FMRP-USP) in Brazil, reported in an article in the journal Psychological Medicine, finds for the first time that individuals exposed to a combination of these two factors - the presence of pro-inflammatory cytokines in the blood and cannabis use (either daily or during adolescence) - are more likely to suffer from psychosis than those who are exposed to neither or to only one. According to the authors, the study provides "the first clinical evidence that immune dysregulation modifies the cannabis-psychosis association".