Functional magnetic resonance imaging studies of emotional processing in normal and depressed patients: effects of venlafaxine.
BACKGROUND
Functional magnetic resonance imaging (fMRI) techniques were used to identify the neural circuitry underlying emotional processing in control and depressed subjects. Depressed subjects were studied before and after treatment with venlafaxine. This new technique provides a method to noninvasively image regional brain function with unprecedented spatial and temporal resolution.


METHODS
Echo-planar imaging was used to acquire whole brain images while subjects viewed positively and negatively valenced visual stimuli. Two control subjects and two depressed subjects who met DSM-IV criteria for major depression were scanned at baseline and 2 weeks later. Depressed subjects were treated with venlafaxine after the baseline scan.


RESULTS
Preliminary results from this ongoing study revealed three interesting trends in the data. Both depressed patients demonstrated considerable symptomatic improvement at the time of the second scan. Across control and depressed subjects, the negative compared with the positive pictures elicited greater global activation. In both groups, activation induced by the negative pictures decreased from the baseline scan to the 2-week scan. This decrease in activation was also present in the control subjects when they were exposed to the positive pictures. In contrast, when the depressed subjects were presented with the positive pictures they showed no activation at baseline, whereas after 2 weeks of treatment an area of activation emerged in right secondary visual cortex.


CONCLUSIONS
While preliminary, these results demonstrate the power of using fMRI to study emotional processes in normal and depressed subjects and to examine mechanisms of action of antidepressant drugs.
Kalin
N H
NH
Department of Psychiatry, University of Wisconsin, Madison 53719-1179, USA.
Davidson
R J
RJ
Irwin
W
W
Warner
G
G
Orendi
J L
JL
Sutton
S K
SK
Mock
B J
BJ
Sorenson
J A
JA
Lowe
M
M
Turski
P A
PA
D000293:Adolescent; D000328:Adult; D001921:Brain / Q000033:anatomy & histology / Q000187:drug effects / Q000502:physiology*; D003511:Cyclohexanols / Q000494:pharmacology* / Q000627:therapeutic use; D003866:Depressive Disorder / Q000175:diagnosis* / Q000188:drug therapy / Q000523:psychology; D017352:Echo-Planar Imaging; D004644:Emotions / Q000187:drug effects / Q000502:physiology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011569:Psychiatric Status Rating Scales; D017367:Selective Serotonin Reuptake Inhibitors / Q000494:pharmacology* / Q000627:therapeutic use; D016896:Treatment Outcome; D000069470:Venlafaxine Hydrochloride; D014793:Visual Cortex / Q000033:anatomy & histology / Q000187:drug effects / Q000502:physiology; D014796:Visual Perception / Q000502:physiology
D003511:Cyclohexanols; D017367:Selective Serotonin Reuptake Inhibitors; D000069470:Venlafaxine Hydrochloride