“…Thus far, studies have linked the CNR1 G allele with reduced bilateral hippocampal volumes (Schacht et al, 2012) and increased cannabis cue-reactivity in PFC-cingulate regions (Filbey et al, 2009), C allele with increased trait anxiety (Bidwell et al, 2013), withdrawal and negative affect following abstinence (Haughey et al, 2008), and increased craving following cannabis cues (Haughey et al, 2008) in young adult cannabis users. No links between CNR1 genotype and behavioral problems, impulsivity (Bidwell et al, 2013) or amygdala volumes (Schacht et al, 2012) have been found. Cannabis-using carriers of the FAAH C allele have demonstrated greater PFC, cingulate and nucleus accumbens activation (Filbey et al, 2009) and increased withdrawal (Schacht et al, 2009) and craving (Haughey et al, 2008) symptoms following cannabis cue exposure.…”