Neuropsychological performance across symptom dimensions in pediatric obsessive compulsive disorder.

Background: Few studies have examined neuropsychological functioning among youth with obsessive compulsive disorder (OCD), with inconclusive results. Although methodological differences may contribute to inconsistent findings, clinical factors may also account for differential performance. Symptom dimensions are associated with specific patterns of genetic transmission, comorbidity, and treatment outcome, and may also be uniquely associated with neuropsychological performance. This study examined differences in cognitive sequelae and neurocognitive impairment across symptom dimensions among youth with OCD.

Method: Participants included 93 treatment-seeking youth diagnosed with OCD. A trained clinician administered the Children's Yale-Brown Obsessive Compulsive Scale (CY-BOCS) to parents and children together. Afterward, youth completed a battery of neuropsychological tests that assessed nonverbal memory and fluency, verbal memory, verbal fluency, verbal learning, processing speed, and inhibition/switching.

Results: Across five symptom dimensions, youth exhibiting Hoarding symptoms (χ(2) = 5.21, P = .02) and Symmetry/Ordering symptoms had a greater occurrence of cognitive sequelae (χ(2) = 4.86, P = .03). Additionally, youth with Symmetry/Ordering symptoms had a greater magnitude of cognitive impairment (Mann-Whitney U = 442.50, Z = -2.49, P < .02), with specific deficits identified on nonverbal fluency (P < .01), processing speed (P < .01), and inhibition and switching (P < .02).

Conclusions: Neuropsychological deficits identified in youth with Hoarding and Symmetry/Ordering symptoms may suggest that these symptoms have characteristics specific to neurocognitive impairment. Alternatively, symptoms associated with these dimensions may impede youth's performance during testing. Findings advise neuropsychological testing for youth with symptoms on either of these dimensions when concerns about neuropsychological and/or academic impairment are present.