Stereotypic Movement Disorder 77
ity. However, if the motor difficulties are in excess of what could be  accounted for by the
intellectual disability, and crit eria for developmental coordination disorder are met, de-
velopmental coordination disorder can be diagnosed as well. 
Attention-deficit/hyperactivity disorder. Individuals with ADHD may fall, bump into
objects, or knock things over. Careful observat ion across different contexts is required to
ascertain if lack of motor competence is at tributable to distract ibility and impulsiveness
rather than to developmental coordination disorder. If criteria for both ADHD and devel-
opmental coordination disorder are met, both diagnoses can be given.
Autism spectrum disorder. Individuals with autism spectrum disorder may be uninter-
ested in participating in task s requiring complex coordination skills, such as ball sports,
which will affect test performance and function but not reflect core motor competence. Co-
occurrence of developmental coordination disorder and autism spectr um disorder is com-
mon. If criteria for both  disorders are met, both diagnoses can be given.
Joint hypermobility syndrome. Individuals with syndrome s causing hyperextensible
joints (found on ph ysical examination; often with a complaint of pain) may present with
symptoms similar to those of deve lopmental coordination disorder.
Comorbidity
Disorders that commonly co-occur with deve lopmental coordination  disorder include
speech and language disorder; specific learning disorder (especially reading and writing);
problems of inattention, incl uding ADHD (the most frequent coexisting condition, with
about 50% co-occurrence); autism spectrum disord er; disruptive and emotional behavior
problems; and joint hypermobility syndrome. Different clusters of co-occurrence may be
present (e.g., a cluster with severe reading di sorders, fine motor problems, and handwriting