Motor proficiency of persons with attention deficit hyperactivity disorder or autism spectrum disorder diagnosed in adulthood

Purpose: To compare (1) motor proficiency of persons diagnosed in adulthood with attention deficit hyperactivity disorder (ADHD) or autism spectrum disorder (ASD) with normative values of motor proficiency, and (2) motor proficiency between persons with ADHD and those with ASD diagnosed in adulthood. Methods: A total of 153 adults (median age 32 years, 36% women) participated in this cross-sectional study. Fifty-three persons with predominately inattentive presentation (ADHD-I), 67 persons with combined presentation (ADHD-C), and 33 persons with ASD performed the Bruininks-Oseretsky Test of Motor Proficiency (BOT-2). One-sample binominal tests were used to compare motor proficiency against standardized norms of BOT-2 for young adults. One-way ANOVAs and Kruskal-Wallis tests were used to compare test outcomes between the groups. Results: The total sample showed significantly impaired motor proficiency in comparison to norms in all test domains (p < 0.001-0.006), except for fine motor skills. The ASD group showed significantly poorer body coordination compared with the ADHD-I and ADHD-C groups, with a moderate effect size (p = 0.003-0.02, eta(2) = 0.061). Conclusions: Motor proficiency is impaired in most persons with ADHD or ASD diagnosed in adulthood, suggesting that motor assessment should be included in clinical examinations of adults with suspected neurodevelopment disorders.