Table 3.

Summary of findings in studies with AEA elevation by FAAH inhibition.

Study	Group (N)	Pharmacological Treatment	Mechanism of Action	Experimental Paradigm	Phase of fear Learning	CSs	US	Psychophysiological Measure	Main Findings
Mayo et al. [143]	FAAH inhibitor treatment (16) Placebo treatment (29)	4 mg/day of PF-04457845 (FAAH inhibitor) Placebo	PF-04457845 is an inhibitor of FAAH	10 days	Habituation Acquisition Extinction Recall Renewal	Two lamps shown in two different contexts	Auditory tone	SCR, ECG, and EMG	The FAAH inhibitor group showed lower responses to the CS+ on day 2, indicating enhanced recall of extinction memory
Paulus et al. [146]	FAAH inhibitor treatment (22) Placebo treatment (21)	100 mg/day of JNJ-42165279 (FAAH inhibitor) Placebo	JNJ-42165279 is an inhibitor of FAAH	4 days	Habituation Acquisition Extinction	Fractal stimuli	Auditory tone	fMRI	No differences between groups during the acquisition and extinction phases

Notes. FAAH = fatty acid amide hydrolase; SCR = skin conductance response; ECG = electrocardiogram; EMG = electromyography; fMRI = functional magnetic resonance imaging.