Therefore, reduced platelet MAO-B activity found in smokers and non-smokers with psychotic (items P1 + P2 + P3 + P6) and positive (items P1 + P2 + P3 + P4 + P5 + P6 + P7) symptoms was induced by the significantly lower platelet MAO-B activity associated with delusions, conceptual disorganisation, hallucinatory behavior, and excitement (Table 3 and Table 4). The gene discussed is MAOB; the disease is Delusion.