Attention-deficit/hyperactivity disorder and phonological working memory: Methodological variability affects clinical...

Area of Science:

• Neuroscience
• Developmental Psychology
• Clinical Psychology

Background:

• Impaired working memory (WM) is a proposed neurocognitive deficit and endophenotype in attention-deficit/hyperactivity disorder (ADHD).
• Previous translational research findings on ADHD-related WM deficits have been inconsistent, necessitating further investigation into methodological influences.

Purpose of the Study:

• To systematically examine how methodological variability affects working memory (WM) performance estimates in children with and without ADHD.
• To clarify equivocal findings in previous research regarding WM deficits as a candidate endophenotype of ADHD.

Main Methods:

• The study involved age-matched boys (8-12 years) with (n=20) and without (n=20) ADHD.
• Participants completed one experimental (phonological) and two clinical (digit span, letter-number sequencing) WM measures.

Main Results:

• Specific procedures, including partial scoring, increased trial administration, and high central executive demands, yielded moderate-to-large effect sizes for group differences.
• Employing these 'best-case' procedures over 'worst-case' ones improved correct group classification by 12.5%.

Conclusions:

• Methodological inconsistencies explain prior equivocal findings on ADHD-related WM deficits.
• Revised clinical measures incorporating optimized 'best-case' procedures are recommended for more accurate ADHD assessment.