Inhibitory control and impulsive responses in neurodevelopmental disorders

Area of Science:

• Neuroscience
• Developmental Psychology
• Clinical Psychology

Background:

• Impaired inhibitory control is frequently hypothesized as a core deficit in neurodevelopmental disorders marked by poor impulse control.
• However, the extent to which a singular deficit in inhibition can explain diverse clinical presentations across these disorders remains debated.

Purpose of the Study:

• To critically review and discuss studies examining inhibitory control deficits in five specific neurodevelopmental disorders: Tourette syndrome, obsessive-compulsive disorder, attention-deficit/hyperactivity disorder, primary motor stereotypies, and autism spectrum disorder.
• To determine if inhibitory deficits represent a transdiagnostic feature of these disorders.

Main Methods:

• Systematic review and discussion of behavioral studies that employed standardized tasks and homogenous samples.
• Focus on disorders including Tourette syndrome, obsessive-compulsive disorder, attention-deficit/hyperactivity disorder, primary motor stereotypies, and autism spectrum disorder.

Main Results:

• Evidence from behavioral studies is mixed, partly due to the complexity of inhibition and methodological variations.
• Studies meeting stringent criteria suggest that the mechanisms underlying urge control are highly heterogeneous across the reviewed disorders.
• The findings do not support a general impairment of inhibition as a transdiagnostic feature.

Conclusions:

• The mechanisms responsible for the inability to control urges in neurodevelopmental disorders are not uniform.
• Inhibition impairments alone cannot account for the varied clinical phenotypes observed in neurodevelopmental disorders characterized by poor impulse control.