Effect of a single dose of citalopram on amygdala response toemotional faces

BackgroundSelective serotonin reuptake inhibitors (SSRIs) are typically thought tohave a delay of several weeks in the onset of their clinical effects.However, recent reports suggest they may have a much earlier therapeuticonset. A reduction in amygdala responsivity has been implicated in thetherapeutic action of SSRIs.AimsTo investigate the effect of a single dose of an SSRI on the amygdalaresponse to emotional faces.MethodTwenty-six healthy volunteers were randomised to receive a single oraldose of citalopram (20 mg) or placebo. Effects on the processing offacial expressions were assessed 3 h later using functional magneticresonance imaging.ResultsVolunteers treated with citalopram displayed a significantly reducedamygdala response to fearful facial expressions compared withplacebo.ConclusionsSuch an immediate effect of an SSRI on amygdala responses to threatsupports the idea that antidepressants have an earlier onset oftherapeutically relevant effects than conventionally thought.