Neurocognitive performance in children with ADHD and OCD

Area of Science:

• Neuroscience
• Cognitive Psychology
• Child Psychiatry

Background:

• Attention-deficit/hyperactivity Disorder (ADHD) and obsessive-compulsive disorder (OCD) are associated with cortico-striato-thalamo-cortical circuitry (CSTCC) dysfunction.
• The specific neurocognitive deficits in ADHD and OCD require further investigation.

Purpose of the Study:

• To investigate distinct neurocognitive deficits in ADHD and OCD using tasks assessing implicit learning and motivational processes.
• To compare performance on a serial reaction time (SRT) task and a delay aversion (DA) task in boys with ADHD, OCD, and healthy controls.

Main Methods:

• A serial reaction time (SRT) task was used to assess implicit sequence learning.
• A delay aversion (DA) task was employed to evaluate abnormal motivational processes.
• Performance data from 20 boys with ADHD, 20 with OCD, and 25 healthy controls (aged 10-18) were analyzed.

Main Results:

• Boys with ADHD showed a greater tendency to avoid delayed rewards compared to OCD and control groups.
• The OCD group exhibited deficits in implicit learning, unlike the ADHD group.
• ADHD group performance on implicit learning was unimpaired, and the OCD group did not display delay aversion.

Conclusions:

• A double dissociation in cognitive functions was observed between ADHD and OCD.
• Implicit learning deficits in OCD correlate with obsession severity.
• Delay aversion in ADHD is associated with impulsive symptoms.
• These findings suggest distinct neural abnormalities underlying ADHD and OCD.