Decrease in thalamic volumes of pediatric patients with obsessive-compulsive disorder who are taking paroxetine.
BACKGROUND
Thalamic dysfunction has been implicated in obsessive-compulsive disorder (OCD). While OCD frequently has its onset during childhood, to our knowledge, no prior study has measured neuroanatomical changes in the thalamus of patients with OCD near the onset of illness, and before and after treatment.


METHODS
Volumetric magnetic resonance imaging studies were conducted in 21 psychotropic drug-naive children, aged 8 to 17 years, with OCD and 21 case-matched healthy comparison subjects. Magnetic resonance imaging studies were also conducted in 10 of the 21 patients with OCD after 12 weeks of monotherapy with the selective serotonin reuptake inhibitor, paroxetine hydrochloride.


RESULTS
Thalamic volumes were significantly greater in treatment-naive patients with OCD than in controls but declined significantly after paroxetine monotherapy to levels comparable with those of controls. Decrease in thalamic volume in patients with OCD was associated with reduction in OCD symptom severity.


CONCLUSIONS
Our findings provide new evidence of thalamic abnormalities in pediatric OCD and further suggest that paroxetine treatment may be paralleled by a reduction in thalamic volume. These reductions may, however, not be specific to paroxetine treatment and could be due to a more general treatment response, and/or spontaneous improvement in symptoms. Our findings are preliminary given the small sample size and our inability to measure discrete thalamic nuclei.
Gilbert
A R
AR
Department of Psychiatry, Wayne State University School of Medicine, Detroit, Mich, USA.
Moore
G J
GJ
Keshavan
M S
MS
Paulson
L A
LA
Narula
V
V
Mac Master
F P
FP
Stewart
C M
CM
Rosenberg
D R
DR
D000293:Adolescent; D000367:Age Factors; D002648:Child; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000706:statistics & numerical data*; D008297:Male; D009771:Obsessive-Compulsive Disorder / Q000175:diagnosis / Q000188:drug therapy* / Q000503:physiopathology; D017374:Paroxetine / Q000494:pharmacology / Q000627:therapeutic use*; D011569:Psychiatric Status Rating Scales / Q000706:statistics & numerical data; D017367:Selective Serotonin Reuptake Inhibitors / Q000494:pharmacology / Q000627:therapeutic use*; D012720:Severity of Illness Index; D012737:Sex Factors; D013788:Thalamus / Q000033:anatomy & histology* / Q000187:drug effects / Q000503:physiopathology; D016896:Treatment Outcome
D017374:Paroxetine; D017367:Selective Serotonin Reuptake Inhibitors