EX-597 (former developmental code names URB-597, KDS-4103, and ORG-231295) is a fatty acid amide hydrolase inhibitor (FAAH inhibitor)[1] which is under development for the treatment of social anxiety disorder (or social phobia) and post-traumatic stress disorder (PTSD).

[2] It is a relatively selective and irreversible inhibitor of the enzyme fatty acid amide hydrolase (FAAH).

EX-597 has been found to elevate anandamide levels and have activity against neuropathic pain in a mouse model.

[5] Preclinical studies have shown FAAH inhibitors to increase brain-derived neurotrophic factor (BDNF) levels in the hippocampus and prefrontal cortex,[6] highlighting their potential in addiction treatment as "enviromimetics".

[7] Indeed, Chauvet et al. found that chronic EX-597 administration in rats "significantly reduces cocaine-seeking behaviour and cue- and stress-induced relapse".