Developmental Coordination Disorder

Definition

Developmental Coordination Disorder (DCD) is a common condition affecting about eight per cent of all boys and two per cent of all girls. It is extremely common in a number of disorders subsumed under the ESSENCE umbrella and is present in at least half of all children with “main diagnoses” of ADHD, ASD, SLI and/or IDD. It does not seem to be extremely common in tic disorders/Tourette syndrome. In the context of ADHD, DCD usually confers increased risk of language problems and autistic features, whereas in cases not showing signs of DCD, ODD and conduct disorder are much overrepresented.

Symptoms

The symptoms of DCD are overall coordination difficulties, gross motor clumsiness, balance problems, hypotonia and poor fine motor skills. Visual perception is also often negatively affected. The disorder is recognisable in the preschool years, but the diagnosis is usually not made until school age, if at all. The most conspicuous gross motor clumsiness is often evident in childhood and the affected individual often has problems learning to ride a bike, to ski, skate and play ball (there is usually a particular problem around group games, but good skills can sometimes be developed in "non-group" games or sports, such as tennis or badminton). PE is almost always a problem, and many children with DCD are actively or indirectly excluded from PE activities. The hypotonia contributes to an impression of "overflexible joints" and often also to poor posture and "awkward" body language. Managing pens, pencils, crayons and cutlery can be major problems affecting, in the end, academic output and table manners. The muscles of the speech apparatus are often also affected leading to articulation problems and slowing down of speech speed.

Causes and consequences

DCD is often inherited, often together with one or more of the other ESSENCE disorders. There is also a higher rate of pregnancy and birth complications in the background of DCD, comparable to rates found in other ESSENCE disorders, such as ADHD and ASD.
Anxiety and depression often follow in the footsteps of DCD, and many children are miserable because of their poor coordination and clumsiness. Unfortunately, the problem, even when obvious, is often not diagnosed and help is not offered.

Assessment and treatment

In our studies at the GNC (and previously in the Department of Child and Adolescent Psychiatry) we have always taken a keen interest in DCD, where it has been studied "in its own right" and as a common comorbidity in ADHD and ASD. DCD can, and should be, assessed, diagnosed, and treated. Information to children, parents and teachers about the nature of the disorder and instructions as to how to work "with and around" the problems are usually helpful. Training of muscular strength, executive function and general physical condition have all been shown to have some positive effect. Central stimulants and focused motor training can be very effective in reducing problems associated with poor fine motor skills. Martial arts, working memory training programs, and specific programs designed for the individual are effective in mitigating the DCD symptoms and can go a long way towards alleviating anxiety and depression. 
Guidelines for the clinical assessment and intervention in DCD have recently been published in Developmental Medicine and Child Neurology (Blank et al 2019): International clinical practice recommendations on the definition, diagnosis, assessment, intervention, and psychosocial aspects of developmental coordination disorder.

DCDs, together with IDD and borderline intellectual functioning, are currently among the most neglected problems in the whole field of developmental medicine/child neuropsychiatry.