Intellectual disability as a disorder of reasoning and judgement: the gradual move away from intelligence quotient-ceilings.
OBJECTIVE
Adoption of the term intellectual disability (intellectual developmental disorder, IDD) in DSM-5 represents a shift from a disability (test score) emphasis to a disorder (medical/neurobiological) emphasis. Several implications of this shift for definition and diagnosis of intellectual disability (ID) are discussed.


RESULTS
The intellectual disability (IDD) section of DSM-5 reflects a growing concern about excessive and inappropriate reliance on intelligence quotient (IQ) cut-offs. Clinicians are now encouraged to take into account various sources of test error; rely more on neuropsychological profiles of cognitive impairments; and approach the adaptive functioning of patients with a greater emphasis on cognitive aspects, such as risk-unawareness.


CONCLUSIONS
A psychometric approach to intellectual disability/IDD, defining it solely in terms of test scores, is inappropriate for psychiatric and medical disorders, which use a disorder rather than a disability model. The intellectual disability/IDD section in DSM-5 is the first prototypical attempt to broaden the category, and approach it in more clinical terms, while still maintaining the meaning of the condition.
aDepartment of Educational Psychology, University of Connecticut, Mansfield, Connecticut bDepartment of Psychiatry, Morehouse School of Medicine, Atlanta, Georgia, USA.
Stephen
S
Greenspan
George W
GW
Woods
D003072:Cognition Disorders / Q000175:diagnosis; D002658:Developmental Disabilities / Q000175:diagnosis*; D039721:Diagnostic and Statistical Manual of Mental Disorders; D006801:Humans; D008607:Intellectual Disability / Q000175:diagnosis*; D009483:Neuropsychological Tests; D011594:Psychometrics; D009626:Terminology as Topic