title: FDG-PET predictors of response to behavioral therapy and pharmacotherapy in obsessive compulsive disorder.
abstract: In subjects with obsessive-compulsive disorder (OCD), lower pre-treatment metabolism in the right orbitofrontal cortex (OFC) and anterior cingulate gyrus (AC) has been associated with a better response to clomipramine. We sought to determine pre-treatment metabolic predictors of response to behavioral therapy (BT) vs. pharmacotherapy in subjects with OCD. To do this, [18F]fluorodeoxyglucose positron emission tomography scans of the brain were obtained in subjects with OCD before treatment with either BT or fluoxetine. A Step-Wise Variable Selection was applied to normalized pre-treatment glucose metabolic rates in the OFC, AC, and caudate by treatment response (change in Yale-Brown Obsessive-Compulsive Scale) in the larger BT group. Left OFC metabolism (normalized to the ipsilateral hemisphere) alone was selected as predicting treatment response in the BT-treated group (F = 6.07, d.f. = 1,17, P = 0.025). Correlations between normalized left OFC metabolism and treatment response revealed that higher normalized metabolism in this region was associated with greater improvement in the BT-treated group (tau = 0.35, P = 0.04), but worse outcome (tau = -0.57, P = 0.03) in the fluoxetine-treated group. These results suggest that subjects with differing patterns of metabolism preferentially respond to BT vs. medication.
authors.affiliation: UCLA Department of Psychiatry and Biobehavioral Sciences, Los Angeles, CA, USA. abrody@ucla.edu
authors.forename: A L
authors.initials: AL
authors.lastname: Brody
authors.forename: S
authors.initials: S
authors.lastname: Saxena
authors.forename: J M
authors.initials: JM
authors.lastname: Schwartz
authors.forename: P W
authors.initials: PW
authors.lastname: Stoessel
authors.forename: K
authors.initials: K
authors.lastname: Maidment
authors.forename: M E
authors.initials: ME
authors.lastname: Phelps
authors.forename: L R
authors.initials: LR
authors.lastname: Baxter
mesh_terms: D000328:Adult; D000929:Antidepressive Agents, Tricyclic / Q000627:therapeutic use*; D001521:Behavior Therapy / Q000379:methods*; D001921:Brain / Q000000981:diagnostic imaging* / Q000378:metabolism; D002997:Clomipramine / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009771:Obsessive-Compulsive Disorder / Q000175:diagnosis* / Q000628:therapy*; D014055:Tomography, Emission-Computed
chemical_list: D000929:Antidepressive Agents, Tricyclic; D002997:Clomipramine