Citalopram and Stress Reactivity

This study is investigating whether acute administration of citalopram is associated with a decrease in stress reactivity in healthy volunteers, compared to placebo administration. Using a parallel-group double-blind design, participants will be randomised to receive either an acute dose of citalopram or placebo. All participants will have come in for a screening visit. On the day of the research visit (following drug administration) participants will have completed a number of widely used computer-based cognitive tasks measuring emotional processing biases. They will then complete the Oxford Cognition Stress Task, a web-based acute stress induction paradigm, which is designed to induce mild transient increases in stress and arousal. Identifying early changes in stress reactivity following antidepressant treatment will increase the investigator's knowledge of how antidepressants operate, and provide putative targets to identify early response to antidepressants.