Information processing, neuropsychological, and neurobiological processes in pediatric obsessive-compulsive disorder.

For Pediatric Obsessive-Compulsive Disorder (OCD) cognitive behavioral therapy (CBT) (with or without SSRI) is the initial treatment of choice. This treatment is found to be moderately effective. However, working mechanisms of CBT are unclear. Models on which CBT is based are hardly studied in children and adolescents. Knowledge about these issues is needed to improve treatment of OCD.
Cognitive theories propose that dysfunctional cognitions play a maintaining or even etiological role in OCD. Other theorists assume that a domain-specific deficit in the ability to inhibit impulses is the core problem of OCD. Furthermore, from a neurobiologically perspective, deviations in the prefrontal-striatal-thalamic circuit are considered to play a centrol role in the development and maintenance of OCD.
The purpose of this study is to determine some information-processing, neuropsychological and neurobiological mechanisms that contribute to the development and maintenance of OCD and/or mediate cognitive-behavioral treatment of OCD.

Information-processing:
1. Changes in measures of severity of OCD are explained (partially) by changes in measures of meta-cognitions (explicit and/or implicit);
2. Changes in measures of meta-cognitions (explicit and implicit) precede changes in measures of severity of OCD.
Neuropsychological processes:
1. Changes in measures of severity of OCD are explained (partially) by changes in measures of inhibition of attentional processes;
2. Changes in measures of inhibition precede changes in measures of severity of OCD.
Neurobiological processes:
1. Volumes of prefrontal cortex and striatum, activity of anterior cingulate, orbitofrontal region and striatum differ from healthy controls and change during treatment.

1. 16 weekly sessions Cognitive Behavioral Therapy (CBT);
2. Waitlist (8 weeks) followed by 16 weekly sessions CBT.