32 Neurodevelopmental Disorders
be met based on historical information, although the current presentation must cause sig-
nificant impairment.
Within the diagnosis of autism spectrum disorder, individual clinical characteristics
are noted through the use of specifiers (with or without accompanying intellectual impair-
ment; with or without accompan ying structural language im pairment; associated with a
known medical/genetic or environmental/acquired condition; associated with another
neurodevelopmental, mental, or behavioral disorder), as well as specifiers that describe
the autistic symptoms (age at first concern; wi th or without loss of established skills; sever-
ity). These specifiers provide clinicians with an opportunity to individualize the diagnosis
and communicate a richer clinical description of  the affected individuals. For example, many
individuals previously diagnosed with Asperg er’s disorder would now receive a diagnosis
of autism spectrum disorder without language or intellectual impairment.
ADHD is a neurodevelopmental disorder defined by impairing levels of inattention, dis-
organization, and/or hyperactivity-impulsivity. Inattention and disorganization entail inabil-
ity to stay on task, seeming not to listen, and lo sing materials, at leve ls that are inconsistent
with age or developmental level.  Hyperactivity-impulsivity entails  overactivity, fidgeting, in-
ability to stay seated, intruding into other people’s activities , and inability to wait—symptoms
that are excessive for age or developmental level. In childhood, ADHD frequently overlaps
with disorders that are often considered to be “externalizing disorders,” such as oppositional
defiant disorder and conduct di sorder. ADHD often persists in to adulthood, with resultant
impairments of social, academic and occupational functioning.
The neurodevelopmental motor disorders in clude developmental coordination disor-
der, stereotypic movement disorder, and tic disorders. Developmen tal coordination dis-