[Source: Your Therapy Source]
The Journal of Attention Disorders published research on the prevalence of dysgraphia by age across all grade levels was determined in students with ADHD or autism. Previous research indicates that children with ADHD and autism show poorer handwriting quality (e.g., legibility, letter formation, alignment, spacing, and sizing) and reduced handwriting speed.
This study included 1034 children with normal intelligence and ADHD–Combined, ADHD–Inattentive, or autism. Each participant completed the Developmental Test of Visual-Motor Integration (VMI) and Wechsler Intelligence Scale for Children (WISC).