Why gender matters: differential effects of stress and alcohol on cortisol secretion and neural stress circuitry activation among sensation seeking and anxiety-sensitive males and females

European Journal of Psychotraumatology

关键词: alcohol;    sensation seeking;    anxiety sensitivity;    fMRI;    cortisol;    stress response;    amygdale;    orbitofrontal cortex;   

DOI  :  10.3402/ejpt.v3i0.19345

来源: DOAJ

【 摘 要 】

Background : Alcohol Use Disorders (AUDs) are multiphasic, multifactorial, and heterogeneous disorders for which the differential risk traits have been proposed to be associated with distinct risk profiles. However, whether these profiles are distinct in terms of neuronal and hormonal mechanisms remains less understood. Behavioral evidence has demonstrated differential motivational systems mediating the response to alcohol, two of which are the psychomotor/cue for reward and the anxiety systems that are in turn exemplified by sensation seeking (SS) and anxiety sensitive (AS) individuals, respectively. Methods : Two equally divided groups of healthy social drinker AS and SS males and females (n=48; ages 18–26) underwent a randomized double-blind placebo-controlled fMRI design. Salivary cortisol concentration was measured every 10 min during testing. Alcohol and placebo were administered based on standardized procedures, 30 min after which scanning occurred at the height of the blood alcohol curve. Two stressors differing in form and effect were used, a random presentation of standardized emotional faces, and a mental math test [The Montreal Imaging Stress Task (MIST)] performed under and accompanied by social pressure, 50–60% uncontrollable failure rate and negative feedback. Results : Salivary cortisol secretion relative to ground (AUCg) was significantly different between groups and within subjects. Gender showed a significant main effect (F(1,39) = 0.6816, p = 0.013), with a females showing greater cortisol response than males. Further, a significant trait-by-gender-by-condition interaction effect was observed (F(1,39) = 6.414, p=0.015), where F_AS showed elevated AUCg under placebo, a response was largely blunted by alcohol. This interaction effect was also significant in terms of amygdalae and orbitofrontal cortical activation under MIST; both regions where significantly deactivated under alcohol in F_AS (parameter estimates, p<0.05 respectively: –2.103; –2.229). Conclusions : These findings provide evidence for the notion that distinct risk personality profiles are associated with differential vulnerability for AUDs. They further support the self-medication theory, whereby AS individuals drink to dampen stress, rendering the former a negative reinforcer targeting and inhibiting their neural and hormonal stress circuitry.