In humans, a randomized, double-blinded study showed that CBD treatment produced clinical improvement of some symptoms of schizophrenia that is accompanied by a significant increase in serum levels of anandamide (AEA), resulted from the inhibition of the fatty-acid amide hydrolase (FAAH), enzyme that metabolizes this endocannabinoid (Leweke et al., 2012). Here, FAAH is linked to schizophrenia.