Influence of alcohol on the processing of emotional facial expressions in individuals with social phobia

Abstract

Individuals with social phobia are at an increased risk to develop alcohol problems. However, the mechanism responsible for this association is unclear. It has been suggested that alcohol reduces anxiety by impairing initial appraisal of threatening stimuli. Information that is especially threatening, however, may be resistant to such an effect of alcohol. We tested the influence of alcohol on the appraisal of five emotional facial expressions. 40 social phobia patients and 40 controls performed a dot probe task, after drinking either alcohol or orange juice. Stimuli were faces with happy, angry, neutral and also two ambiguous expressions that were formed by blending angry or happy faces and neutral faces. Stimuli were presented for either 175 or 600 ms. Sober patients showed an attentional bias towards angry faces, indicating preferential processing of threat stimuli. Alcohol significantly reduced this bias. Only in sober participants, this attentional bias correlated with measures of social anxiety. In controls, no biases were observed. Alcohol seems to attenuate the impact of threatening social stimuli on social phobia patients, which may negatively reinforce the consumption of alcohol and at least partially explain the heightened comorbidity with alcohol related problems known from epidemiological studies. The dot probe task with short stimulus presentation times seems to provide an adequate method to demonstrate alcohol effects on information processing.