Prepotent response inhibition predicts treatment outcome in attention deficit/hyperactivity disorder
S van der Oord1, H M Geurts, P J M Prins
1Clinical Psychology, University of Leuven, Leuven, Belgium. saskia.vanderoord@psy.kuleuven.be
Insights
Children with ADHD and poor response inhibition showed worse outcomes after methylphenidate treatment. This suggests prepotent response inhibition is a key factor in treatment success for attention deficit hyperactivity disorder.
Area of Science:
- Neuroscience
- Child Psychology
- Psychopharmacology
Background:
- Attention deficit hyperactivity disorder (ADHD) is characterized by inhibition deficits.
- These deficits include problems with prepotent response inhibition and interference control.
- Understanding predictors of treatment response is crucial for ADHD management.
Purpose of the Study:
- To assess the predictive value of inhibition deficits for treatment outcomes in ADHD.
- To examine the relationship between prepotent response inhibition and interference control with methylphenidate treatment response.
Main Methods:
- A 10-week methylphenidate treatment trial was conducted with 34 children (ages 8-12) diagnosed with ADHD.
- Prepotent response inhibition was measured using the Stop-Signal Task.
- Interference control was assessed via the Stroop Color-Word task.
- Methylphenidate dosage was individually titrated, and outcomes were evaluated using parent and teacher ratings of ADHD symptoms.
Main Results:
- Stop-signal reaction time from the Stop-Signal Task significantly predicted parent-rated inattention and hyperactivity/impulsivity.
- Lower levels of prepotent response inhibition were associated with poorer treatment outcomes.
- This association was independent of the methylphenidate dosage.
Conclusions:
- Deficits in prepotent response inhibition are linked to a less favorable response to methylphenidate treatment in children with ADHD.
- Prepotent response inhibition may serve as an intermediate phenotypical predictor for treatment outcomes in ADHD.
Objective:
Inhibition deficits, including deficits in prepotent response inhibition and interference control, are core deficits in ADHD. The predictive value of prepotent response inhibition and interference control was assessed for outcome in a 10-week treatment trial with methylphenidate.
Methods:
Thirty-four children with ADHD (ages 8-12) received 10 weeks of methylphenidate treatment. At pretest prepotent response inhibition was assessed using the Stop-Signal Task; interference control was assessed using the Stroop Color-Word task. Methylphenidate was individually titrated to an optimal dose. Treatment outcome was assessed by parent- and teacher-rated ADHD behavior.
Results:
Only stop-signal reaction time of the Stop-Signal Task was a significant predictor of parent-rated levels of inattention and hyperactivity/impulsivity at outcome. Children with lower levels of inhibition showed worse outcome after 10 weeks of treatment, independent of medication dose.
Conclusions:
Low levels of prepotent response inhibition are associated with worse response to treatment with methylphenidate. Prepotent response inhibition may be an intermediate phenotypical predictor of treatment outcome.
