This finding is intriguing given the evidence that blood-derived plasminogen is associated with brain inflammation61 and complement activation.62 In models of multiple sclerosis, blood-brain barrier disruption facilitates transfer of fibrinogen into the brain, where it is deposited as fibrin, causing local inflammation.63 Given evidence for blood-brain barrier disruption in psychosis,64 fibrin may be associated with etiopathogenic mechanisms providing novel therapeutic avenues,65 but this hypothesis requires further investigation. This evidence concerns the gene PLG and psychotic disorder.