The effect of acute tryptophan depletion on the neural correlates of emotional processing in healthy volunteers.
The processing of affective material is known to be modulated by serotonin (5-HT), but few studies have used neurophysiological measures to characterize the effect of changes in 5-HT on neural responses to emotional stimuli. We used functional magnetic resonance imaging to investigate the effect of acute tryptophan depletion, which reduces central 5-HT synthesis, on neural responses to emotionally valenced verbal stimuli. Though no participants experienced significant mood change, emotional information processing was substantially modified following 5-HT depletion. A behavioral bias toward positive stimuli was attenuated following depletion, which was accompanied by increased hemodynamic responses during the processing of emotional words in several subcortical structures. Inter-individual differences in tryptophan depletion-elicited anxiety correlated positively with the caudate bias toward negative stimuli. These data suggest that 5-HT may play an important role in mediating automatic negative attentional biases in major depression, as well as resilience against negative distracting stimuli in never-depressed individuals.
Roiser
Jonathan P
JP
Department of Imaging Neuroscience, Institute of Neurology, London, UK. j.roiser@ion.ucl.ac.uk
Levy
Jamey
J
Fromm
Stephen J
SJ
Wang
Hongye
H
Hasler
Gregor
G
Sahakian
Barbara J
BJ
Drevets
Wayne C
WC
D000293:Adolescent; D000328:Adult; D000339:Affect / Q000502:physiology; D000596:Amino Acids / Q000097:blood; D001794:Blood Pressure / Q000502:physiology; D001921:Brain / Q000502:physiology; D003071:Cognition / Q000187:drug effects; D018592:Cross-Over Studies; D004311:Double-Blind Method; D004644:Emotions / Q000502:physiology*; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D017397:Prefrontal Cortex / Q000502:physiology; D011569:Psychiatric Status Rating Scales; D011597:Psychomotor Performance / Q000502:physiology; D012701:Serotonin / Q000378:metabolism; D012938:Social Perception; D014364:Tryptophan / Q000172:deficiency / Q000502:physiology*
D000596:Amino Acids; D012701:Serotonin; D014364:Tryptophan