Global Developmental Delay

clinical assessment. This is usually tested with a culturally-appropriate, individually-

administered, and psychometrically-sound series of tests of intelligence. Being more than 2

standard deviations below the mean indicate some degree of intellectual disability.

Criterion B involves deficits in adaptive functioning or a failure to meet sociocultural or

developmental standards for personal independence and social responsibility. Without

ongoing social support, these adaptive deficits will limit the individual’s functioning in at least

one area of daily life, such as social participation, communication, and ability to maintain

independent living across multiple areas of the individual’s life, such as school, home, and

recreational activities. It takes a clinical evaluation and individualized testing with reliable

informants and the individual’s own assessment.

The disorder also involves criterion C, which is that the onset of the disease needs to happen

during the developmental period. This basically means prior to the age of 18 years, although it

can usually be evident by the time the child reaches school age.

There are specifiers as to the severity level of the disorder. It can be mild (in the range of IQ 55-

70); moderate (in the range of IQ 40-55); severe (in the range of IQ 25-40); or profound (with an

IQ of less than 25). Remember that IQ scores alone are not diagnostic of the disorder.

Global developmental delay is a term used to describe children who have marked deficits in

both intellectual and physical development. Often, a specifier can be used to indicate the

specific condition the child has. This can include a chromosomal abnormality, such as trisomy

21 or trisomy 18. It can also be the diagnosis in other syndromes, such as fragile X syndrome.

However, specific illness is not required to make the diagnosis.

On the physical side, children may have failure to thrive, which does not have significant

intellectual delay; others can have an intellectual deficit, which focuses more on intellectual

development. The term “developmental disability” is used to describe deficits in both physical

and cognitive development.