Attention Deficit Hyperactivity Disorder 

What is the current evidence about ADHD and DCD?

There is a growing body of evidence suggesting that children with attention deficit/hyperactivity disorder (ADHD) have an extremely high rate of co-occurring DCD. Several studies conducted with children with ADHD found that at least 50% of these children also had DCD. Additionally, a few studies have shown that children with the primarily inattentive subtype of ADHD may have the highest rate of motor impairment.

Children who have both ADHD and DCD also have higher rates of problems in selective language functioning, learning abilities and social skills.  Outcomes for this group of children appear to be much less favourable than for children with DCD alone and they tend to require more services.  Several researchers have suggested that "pure" ADHD is relatively unusual. Based on these findings, all children with attention or learning problems should be assessed for signs of motor impairment.

What might you see?

The overlap between DCD and ADHD can make it difficult to determine whether one or both of these disorders is present. It may appear that children with DCD are not paying attention because they have difficulty keeping their bodies and joints stable, so they look restless. In addition, they may not pay attention well to motor-based tasks that are performed in school, especially if they involve handwriting or other manual skills. When motor problems are present, children may purposely avoid tasks that require motor skills and wander around the classroom, asking to use the bathroom, poking and bothering other children and so on.

The reverse of this problem can also be true. Children with ADHD, particularly the inattentive type, may appear to be clumsy because they do not watch carefully when they cross a room or run across a playground.  Children who are hyperactive may bump into other children by accident or have difficulty focusing during ball games.  As has been mentioned, at least 50% of children with ADHD also have motor-based problems significant enough to meet the diagnosis of DCD. Careful observation of the types of tasks and settings that are most difficult for the child as well as input from health care professionals can be very helpful in determining which disorders may be present.