MAOB and schizophrenia: Reduced platelet MAO-B activity related to delusions and hallucinatory behavior in PTSD is in line with the older data that reported significantly lower platelet MAO-B activity in male patients with the paranoid subtype of schizophrenia, auditory hallucinations, and paranoia [55], or with the presence of hallucinations [56] or auditory hallucinations in schizophrenia [57] compared with controls.