In comparison with the inhibition or genetic deletion of COX-1, which also counteracts the development of the depressive syndrome [112,113] and is functionally related to COX-2 [114,115], COX-2 inhibitors may display better compliance, since the constitutively expressed COX-1 is responsible for the maintenance of peripheral physiological functions and its inhibition causes significant side effects [110]. Here, PTGS2 is linked to depressive disorder.