Global Developmental Delay 41
manual. The AAIDD’s classification is multidimensional rather than categorical and is
based on the disability construc t. Rather than listing specifie rs as is done in DSM-5, the
AAIDD emphasizes a profile of supports based on severity.
Global Developmental Delay
315.8 (F88)
This diagnosis is reserved for individuals under  the age of 5 years when the clinical severity
level cannot be reliably assessed during early childhood. This category is diagnosed when
an individual fails to meet expected developmental  milestones in several areas of intellec-
tual functioning, and applies to individuals  who are unable to undergo systematic assess-
ments of intellectual functioning, including children who are too young to participate in
standardized testing. This category requires reassessment after a period of time.
Unspecified Intellectual Disability
(Intellectual Developmental Disorder)
319 (F79)
This category is rese rved for individuals over the age of 5 years when assessment of the
degree of intellectual disabi lity (intellectual developmental disorder) by means of locally
available procedures is rendered difficult or impossible because of associated sensory or
physical impairments, as in blindness or prel ingual deafness; locomotor disability; or pres-
ence of severe problem behaviors or co-occurring mental disorder. This category should
only be used in exceptional circumstances and requires reassessment after a period of time. 
Communication Disorders
Disorders of communication include deficits  in language, speech, and communication.
Speech  is the expressive production of sounds and includes an indivi dual’s articulation,
fluency, voice, and resonance quality. Language  includes the form, fu nction, and use of a
conventional system of symbol s (i.e., spoken words, sign language, written words, pic-