Cognitive inflexibility and frontal-cortical activation in pediatric obsessive-compulsive disorder.
OBJECTIVE
Deficits in cognitive flexibility and response inhibition have been linked to perturbations in cortico-striatal-thalamic circuitry in adult obsessive-compulsive disorder (OCD). Although similar cognitive deficits have been identified in pediatric OCD, few neuroimaging studies have been conducted to examine its neural correlates in the developing brain. In this study, we tested hypotheses regarding group differences in the behavioral and neural correlates of cognitive flexibility in a pediatric OCD and a healthy comparison (HC) sample.


METHODS
In this functional magnetic resonance imaging (fMRI) study, a pediatric sample of 10- to 17-year-old subjects, 15 with OCD and 20 HC, completed a set-shifting task. The task, requiring an extradimensional shift to identify a target, examines cognitive flexibility. Within each block, the dimension (color or shape) that identified the target either alternated (i.e., mixed) or remained unchanged (i.e., repeated).


RESULTS
Compared with the HC group, the OCD group tended to be slower to respond to trials within mixed blocks. Compared with the HC group, the OCD group exhibited less left inferior frontal gyrus/BA47 activation in the set-shifting contrast (i.e., HC > OCD, mixed versus repeated); only the HC group exhibited significant activation in this region. The correlation between set shifting-induced right caudate activation and shift cost (i.e., reaction time differential in response to mixed versus repeated trials) was significantly different between HC and OCD groups, in that we found a positive correlation in HC and a negative correlation in OCD.


CONCLUSIONS
In pediatric OCD, less fronto-striatal activation may explain previously identified deficits in shifting cognitive sets.
Britton
Jennifer C
JC
Mood and Anxiety Disorders Program at the National Institute of Mental Health in Bethesda, MD, USA.
Rauch
Scott L
SL
Rosso
Isabelle M
IM
Killgore
William D S
WD
Price
Lauren M
LM
Ragan
Jennifer
J
Chosak
Anne
A
Hezel
Dianne M
DM
Pine
Daniel S
DS
Leibenluft
Ellen
E
Pauls
David L
DL
Jenike
Michael A
MA
Stewart
S Evelyn
SE
D000293:Adolescent; D001288:Attention / Q000502:physiology; D001931:Brain Mapping; D002421:Caudate Nucleus / Q000503:physiopathology; D002648:Child; D003071:Cognition / Q000502:physiology*; D003118:Color Perception / Q000502:physiology*; D003342:Corpus Striatum / Q000503:physiopathology; D004292:Dominance, Cerebral / Q000502:physiology; D005260:Female; D005625:Frontal Lobe / Q000503:physiopathology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009771:Obsessive-Compulsive Disorder / Q000175:diagnosis / Q000503:physiopathology* / Q000523:psychology; D009949:Orientation / Q000502:physiology; D010364:Pattern Recognition, Visual / Q000502:physiology*; D011597:Psychomotor Performance / Q000502:physiology; D011930:Reaction Time / Q000502:physiology; D012016:Reference Values; D012193:Reversal Learning / Q000502:physiology*