What does handedness reveal about ADHD? An analysis based on CPT performance

Area of Science:

• Neurodevelopmental disorders
• Cognitive neuroscience
• Child psychology

Background:

• Attention-deficit/hyperactivity disorder (ADHD) is a common developmental disorder impacting attention and behavior.
• Continuous Performance Tests (CPTs) are valuable tools for assessing attention deficits and aiding ADHD diagnosis.
• Handedness, particularly left-handedness, has been anecdotally linked to various neurodevelopmental conditions.

Purpose of the Study:

• To investigate the association between handedness and ADHD.
• To evaluate the efficacy of CPTs in school-based ADHD screening.
• To examine how handedness influences performance on CPTs.

Main Methods:

• Children were categorized by handedness consistency (right-consistent, left-consistent, non-consistent).
• A matched-pair analysis compared 171 controls with 68 ADHD participants on CPT performance.
• Statistical methods including ANOVA and discriminant analysis were employed to assess group differences and predictive validity.

Main Results:

• Left-handed children demonstrated a 2.88 times higher probability of having ADHD compared to right-handed children.
• ADHD participants exhibited significantly more errors and greater reaction time variability on CPTs than controls.
• CPT performance metrics successfully discriminated between ADHD and control groups, with left-handers making more commission errors.

Conclusions:

• The observed association suggests that left-handedness may correlate with reduced hemispheric lateralization and interhemispheric connectivity in ADHD.
• CPTs are confirmed as effective tools for measuring attentional domains in school environments.
• Left-handed individuals with ADHD appear to struggle more with the impulsive and hyperactive components of the disorder.