DNA was collected using the Oragene DNA Self-Collection Kit (DNA Genotek, Ottawa, Ontario, Canada). After DNA extraction, FAAH C385A was assayed using a commercially available 5′-nuclease (TaqMan) assay and an ABI 7500 thermocycler (Advanced Biotechnologies, Columbia, MD, USA). To confirm genotype, samples for each participant were run in triplicate. Primer sequences were, forward, 5′-TCTGGCTGACTGTGAGACTCA-3′ and reverse, 5′-CTCACAGGGACGCCATAGAG-3′.
