SGCB and depressive disorder: CO can be produced by oxidative catabolism through injection of heme oxygenase (HO).[10] CO has a similar affinity to NO-bound sGC, but CO-sGC is 25 to 50 times less active than NO-sGC.[11] This paper describes research on gas therapy for depression and schizophrenia using the endogenous gas production strategies of NO and CO as examples.