A comparison of the effects of citalopram and moclobemide on resting brain perfusion in social anxiety disorder.
BACKGROUND
The serotonin specific reuptake inhibitor (SSRI) citalopram and the reversible mono-amine oxidase-A inhibitor (RIMA) moclobemide have both been used successfully for the treatment of social anxiety disorder (SAD). In this study we investigate the effects of these compounds on resting brain function using single photon emission computed tomography (SPECT).


METHODS
Subjects meeting DSM-IV criteria for SAD underwent regional cerebral blood flow (rCBF) SPECT using Tc-HMPAO at baseline and after 8 weeks of treatment with either citalopram or moclobemide. Using statistical parametric mapping brain SPECT studies were analysed to determine the effects of treatment on rCBF, to compare the effects of citalopram and moclobemide, and to detect correlations between changes in rCBF and clinical response.


RESULTS
Subjects received citalopram (n=17) or moclobemide (n=14) as therapy. Subjects in both treatment groups demonstrated a significant improvement of SAD symptoms as measured by the Liebowitz Social Anxiety Scale total score. All subjects demonstrated a decrease in rCBF in the insulae post therapy. Subjects receiving citalopram had decreased superior cingulate rCBF after therapy compared to those receiving moclobemide.


CONCLUSIONS
Both SSRI's and RIMA's decreased rCBF in the insulae during treatment of SAD; an effect that may be consistent with the role of these regions in processing internal somatic cues evoked by emotional stimuli. Citalopram had a greater effect on superior cingulate perfusion, an effect that is consistent with evidence of high levels of 5-HT transporters in this region.
Warwick
J M
JM
MRC Unit for Stress and Anxiety Disorders, Faculty of Health Sciences, Stellenbosch University, Cape Town, South Africa.
Carey
P
P
Van der Linden
G
G
Prinsloo
C
C
Niehaus
D
D
Seedat
S
S
Dupont
P
P
Stein
D J
DJ
D000328:Adult; D000379:Agoraphobia / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000503:physiopathology*; D000928:Antidepressive Agents / Q000627:therapeutic use*; D001921:Brain / Q000000981:diagnostic imaging; D002560:Cerebrovascular Circulation / Q000187:drug effects / Q000502:physiology*; D015283:Citalopram / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D008297:Male; D020912:Moclobemide / Q000627:therapeutic use*; D011569:Psychiatric Status Rating Scales; D017367:Selective Serotonin Reuptake Inhibitors / Q000627:therapeutic use*; D013028:Space Perception / Q000187:drug effects / Q000502:physiology; D015899:Tomography, Emission-Computed, Single-Photon
D000928:Antidepressive Agents; D015283:Citalopram; D020912:Moclobemide; D017367:Selective Serotonin Reuptake Inhibitors