Spatiotemporal brain activation pattern following acute citalopram challenge is dose dependent and associated with neuroticism: A human phMRI study.

•Intravenous citalopram acutely elicited brain activation in several regions involved in serotonergic neurotransmission.•Acute citalopram challenge produced a chemically-induced brain state similar to increased arousal.•Significant dose-dependent activation was demonstrated in the middle cingulate gyrus, a region with neuroticism-related functions.•The neuroticism personality trait was associated with the individual responses to citalopram challenge.•These results may further support the modulating effects of serotonin on processing environmental stressors.