Gray matter volumes in obsessive-compulsive disorder before and after fluoxetine or cognitive-behavior therapy: a randomized clinical trial.
Serotonin reuptake inhibitors and cognitive-behavior therapy (CBT) are considered first-line treatments for obsessive-compulsive disorder (OCD). However, little is known about their modulatory effects on regional brain morphology in OCD patients. We sought to document structural brain abnormalities in treatment-naive OCD patients and to determine the effects of pharmacological and cognitive-behavioral treatments on regional brain volumes. Treatment-naive patients with OCD (n=38) underwent structural magnetic resonance imaging scan before and after a 12-week randomized clinical trial with either fluoxetine or group CBT. Matched-healthy controls (n=36) were also scanned at baseline. Voxel-based morphometry was used to compare regional gray matter (GM) volumes of regions of interest (ROIs) placed in the orbitofrontal, anterior cingulate and temporolimbic cortices, striatum, and thalamus. Treatment-naive OCD patients presented smaller GM volume in the left putamen, bilateral medial orbitofrontal, and left anterior cingulate cortices than did controls (p<0.05, corrected for multiple comparisons). After treatment with either fluoxetine or CBT (n=26), GM volume abnormalities in the left putamen were no longer detectable relative to controls. ROI-based within-group comparisons revealed that GM volume in the left putamen significantly increased (p<0.012) in fluoxetine-treated patients (n=13), whereas no significant GM volume changes were observed in CBT-treated patients (n=13). This study supports the involvement of orbitofronto/cingulo-striatal loops in the pathophysiology of OCD and suggests that fluoxetine and CBT may have distinct neurobiological mechanisms of action.
Department and Institute of Psychiatry, University of São Paulo Medical School, São Paulo, Brazil.
Marcelo Queiroz
MQ
Hoexter
Fábio Luis
FL
de Souza Duran
Carina Chaubet
CC
D'Alcante
Darin Dean
DD
Dougherty
Roseli Gedanke
RG
Shavitt
Antonio Carlos
AC
Lopes
Juliana Belo
JB
Diniz
Thilo
T
Deckersbach
Marcelo Camargo
MC
Batistuzzo
Rodrigo Affonseca
RA
Bressan
Euripedes Constantino
EC
Miguel
Geraldo Filho
GF
Busatto
D000328:Adult; D001921:Brain / Q000187:drug effects / Q000473:pathology*; D015928:Cognitive Behavioral Therapy; D005260:Female; D005473:Fluoxetine / Q000627:therapeutic use*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009771:Obsessive-Compulsive Disorder / Q000188:drug therapy / Q000473:pathology* / Q000523:psychology / Q000628:therapy*; D009929:Organ Size / Q000187:drug effects; D017367:Selective Serotonin Reuptake Inhibitors / Q000627:therapeutic use*; D016896:Treatment Outcome
D005473:Fluoxetine; D017367:Selective Serotonin Reuptake Inhibitors