There is increasing data supporting the role of endocannabinoid system (eCB) in the control of emotional homeostasis, mainly acting through CB1R activation (Menchoulam&Parker, 2012). eCB seems important to maintain baseline anxiety levels and to recovery/adapt to stressful and aversive situations (Moreira&Luz, 2008). A misbalance in eCB system might contribute to the etiology of anxiety related disorders (Crippa et al., 2009; Marco et al., 2012). The cannabinoid receptor 1 (CNR1) gene has been associated to “high neuroticism” and “low agreeableness” phenotype (Juhasz et al., 2009).

Study the association between personality traits and genetic polymorphisms located in genes related to eCB (CNR1, CNR2, FAAH and MGKLL) in patients with anxiety disorders.

In a case-control study, we analyzed 48 polymophisms tagSNPs in sample of 507 Caucasians subjects of both genders. All were assessed using the Semi-Structural Interview of DSM-IV criteria and the Temperament and Character Inventory of Cloninger. Multiple regression analysis was used to determine whether the different personality traits were associated with each variant in CNr1, CNr2, FAAH, and MGKLL, using age and gender as confounder variables.

A significant association was found between “high Harm-avoidance” trait and rs1049353 in the CNR1 gene (p< 0.005) and rs1157694 in the FAAH gene (p< 0.001). “Low novelty-seeking” trait was associated with rs324490 in the FAAH gene (p< 0.005).

These findings suggest that genetic variations in the CNR1 and FAAH genes may modulate the expression of some clinical aspects of anxiety traits and probably anxiety disorders. Grants: ICIII G03/184; SGR2009/1435.