Evidence for modulation of facial emotional processing bias during emotional expression decoding by serotonergic and noradrenergic antidepressants: an event-related potential (ERP) study.
BACKGROUND
Serotonergic (SSRI) and noradrenergic (NRI) antidepressants modulate biases in emotional processing such that perceptual bias is shifted away from negative and towards positive emotional material. However, the effects of serotonergic and noradrenergic modulation on the temporal course (occurring in milliseconds) of emotional processing, and in particular, the rapid physiological changes associated with the different stages of emotional processing, are unknown.


OBJECTIVE
The current study assessed the effects of acute serotonergic (i.e. with citalopram) and noradrenergic (i.e. with reboxetine) augmentation on event-related potential (ERP) measures associated with 'structural encoding' (N170) and emotion expression decoding (N250 and late positive potential [LPP]) for positive (happy) and negative (sad) facial stimuli relative to neutral facial stimuli.


METHODS
This study employed a double-blind, placebo-controlled, cross-over design in which 12 healthy male participants completed a facial expression recognition task tested under three acute conditions: (a) placebo, (b) citalopram (20 mg) and (c) reboxetine (4 mg).


RESULTS
Both citalopram and reboxetine had no effect on the N170 ERP component associated with structural encoding, but potentiated the N250 associated with happy (relative to neutral) emotional facial expression decoding. Both drugs had no valence effects on later ERP measures of emotion expression decoding (LPP).


CONCLUSIONS
Citalopram and reboxetine have selective effects on the temporal course of emotional processing with evidence to suggest specific effects on emotion expression decoding of positive (happy) emotional facial stimuli as evidenced by changes in the attention-modulated N250 but not structural encoding. These findings provide physiological evidence that antidepressants may shift perceptual biases in emotional processing away from negative and towards positive stimuli.
Kerestes
Rebecca
R
Behavioural Neuroscience Laboratory, School of Psychology, Psychiatry and Psychological Medicine, Monash University, Melbourne, Australia. Rebecca.Kerestes@med.monash.edu.au
Labuschagne
Izelle
I
Croft
Rodney J
RJ
O'Neill
Barry V
BV
Bhagwagar
Zubin
Z
Phan
K Luan
KL
Nathan
Pradeep J
PJ
D000293:Adolescent; D018759:Adrenergic Uptake Inhibitors / Q000494:pharmacology*; D000328:Adult; D000928:Antidepressive Agents / Q000494:pharmacology*; D015283:Citalopram / Q000494:pharmacology; D018592:Cross-Over Studies; D004311:Double-Blind Method; D004569:Electroencephalography; D004644:Emotions; D005071:Evoked Potentials / Q000187:drug effects*; D005149:Facial Expression; D005260:Female; D006801:Humans; D008297:Male; D009025:Morpholines / Q000494:pharmacology; D009638:Norepinephrine / Q000502:physiology; D000077593:Reboxetine; D017367:Selective Serotonin Reuptake Inhibitors / Q000494:pharmacology*; D012938:Social Perception; D055815:Young Adult
D018759:Adrenergic Uptake Inhibitors; D000928:Antidepressive Agents; D015283:Citalopram; D009025:Morpholines; D009638:Norepinephrine; D000077593:Reboxetine; D017367:Selective Serotonin Reuptake Inhibitors