Cognitive mechanisms of diazepam administration: a healthy volunteer model of emotional processing

Benzodiazepine drugs continue to be prescribed relatively frequently for anxiety disorders, especially where other treatments have failed or when rapid alleviation of anxiety is imperative. The neuropsychological mechanism by which these drugs act to relieve symptoms, however, remains underspecified. Cognitive accounts of anxiety disorders emphasise hypervigilance for threat in the maintenance of the disorders. The current study examined the effects of 7- or 8-day administration of diazepam in healthy participants (n = 36) on a well-validated battery of tasks measuring emotional processing, including measures of vigilance for threat and physiological responses to threat. Compared to placebo, diazepam reduced vigilant-avoidant patterns of emotional attention (p < 0.01) and reduced general startle responses (p < .05). Diazepam administration had limited effects on emotional processing, enhancing the response to positive vs negative words in the emotional categorisation task (p < .05), modulating emotional memory in terms of false accuracy (p < .05) and slowing the recognition of all facial expressions of emotion (p = .01). These results have implications for our understanding of the cognitive mechanisms of benzodiazepine treatment. The data reported here suggests that diazepam modulates emotional attention, an effect which may be involved in its therapeutic actions in anxiety.