If present, always diagnosis . Must have significantly sub-average intelligence and deficits in adaptive functioning. Onsent prior to age 18 after 18 diagnosed as Dementia. Must have IQ of 70 or below on a IQ test. The disorder slightly more common in males.
- Borderline Intellectual Functioning: IQ 71-84 Code on Axis II
- Mild: IQ 50-55 to approximately70
- Moderate: IQ 35-40 to 50-55
- Severe: IQ 20-25 to 35-40
- Profound: IQ below 20-25
All IQ score can have a margin of error, equivalent to a five-point overlap.