There are many possible comorbid problems in Asperger syndrome. In fact, there is no other problem or diagnosis (except perhaps another disorder from the autism spectrum and severe mental retardation) that rules out a diagnosis of Asperger syndrome. Some of the most common and important comorbidities and associated problems will be described briefly here.

ADHD

In the vast majority of those with Asperger syndrome there are additional problems with attention deficits of various types. Such deficits, in turn, are often combined with motor coordination problems and other disorders of movement (including catatonic features). Sometimes, the attention deficits are of the extent and type encountered in ADHD and may be combined with overactivity and impulsivity. In other cases, it is more a question of exaggerated slowness and perfectionism leading to the individual not being sufficiently attentive to what goes on in the environment. The child – and adult for that matter – may quite simply be so absorbed by the task at hand that he/she may not notice, or does not care, that parents, teachers, psychologists or doctors are asking them to shift their attention to another task.

In one Swedish study, the great majority of all children meeting diagnostic criteria for Asperger syndrome also met criteria for ADHD with DCD (equals DAMP). Conversely, only a minority of all individuals meeting diagnostic criteria for DAMP show the full syndrome of Asperger's.