Monday 29 August 2011

Abstract

Studies have shown that stress and alcohol-cue exposure can induce alcohol craving with increased cortisol level, hence stress response may be critical in regulating craving and predict relapse. Dopaminergic and serotonergic neurotransmissions play indispensible roles to modulate addictive behaviours through personality and stress response. This study explored the relationships among personality traits, salivary cortisol and alcohol craving in alcohol-dependent subjects, and their associations with gene polymorphisms. Alcohol-dependent subjects ( = 156) were recruited during a five-day detoxification treatment. Personality traits were assessed by NEO PI-R and Tridimensional Character Inventory. Alcohol craving was measured by Alcohol Urge Questionnaire and saliva sample for cortisol measurement. Genotyping was performed by PCR-RFLP. Results showed that alcohol craving correlated with salivary cortisol level in female subjects only (Spearman’s rho = .430, p = 0.022). 5HTTLPR S-allele carriers had significantly higher cortisol level than LL counterparts (Student t test p = 0.019), and a significant correlation between salivary cortisol level and state alcohol craving in females (Spearman’s ρ = 0.466; p = 0.014). Alcohol craving is significantly (p < 0.05) correlated with Neuroticism, Conscientiousness, Novelty-seeking and Reward-dependence personality scores for males with Extraversion, Conscientiousness, Novelty-seeking and Persistence scores for females. Significant correlation between alcohol craving and personality traits was only observed in DRD2 TaqIA A1-allele carriers, whose craving level was negatively correlated with Reward-dependence scores (adjusted r2 = 0.191, p < 0.001). Structural Equation Modeling revealed the effect of DRD2 TaqIA on alcohol craving is mediated through Reward-dependence trait. In conclusion, correlations between alcohol craving, salivary cortisol level and certain personality traits are gender specific. 5HTTLPR S-allele may be associated with higher salivary cortisol level in female alcoholics, which is positively correlated with state alcohol craving. DRD2 A1-allele is associated with alcohol craving level through mediation of the Reward-dependence trait: alcohol-dependent A1-carrying patients with this trait may benefit from a detoxification treatment environment in which alcohol craving level is low.