substitution that converts a conserved proline residue to threonine. A previous study found an association between this SNP and substance abuse [38]. Although the functional significance of this non-synonomous SNP is not understood fully, the 385A variant encodes for a mutant FAAH enzyme characterized by reduced cellular stability compared to the wild-type [41]. Thus, the A variant may lead to lower FAAH enzyme levels, resulting in greater endocannabinoid activity via less efficient degradation of endocannabinoids and in turn may have an impact on measures of withdrawal, craving and mood.
