Development of graphomotor fluency in adults with ADHD: Evidence of attenuated procedural learning

The present study sought to determine if adults with ADHD demonstrate reduced graphomotor learning relative to controls. Twenty-eight control adults ( n   =   14) and adults with ADHD ( n   =   14) were recruited and wrote a novel grapheme on a digitizing tablet 30 times. Participants with ADHD were counterbalanced on and off stimulant medication. Control participants, F (1,   13)   =   13.786, p   =   .003, ω 2 partial   =   .460, and participants with ADHD on medication, F (1,   13)   =   10.462, p   =   .007, ω 2 partial   =   .387, demonstrated significant improvement in graphomotor fluency with equivalent practice whereas participants with ADHD off medication did not, F (1,   12)   =   0.166, NS . Results indicate that graphomotor program learning in adults with ADHD may occur more slowly than typically developing peers. Findings have implications for providing accommodations to adults with ADHD, potential benefits of stimulant medication, and using digitizing technology as a neuropsychological assessment instrument.