The Mental Retardation cutoffs, per DSM-IV:
Mental Retardation IQ Equivalent
Mild 50-55 - 70 6th grade
Moderate 35-40 - 50-55 1st grade
Severe 20-25 - 35-40 Requires constant supervision
Profound below 20-25 Requires constant care
Mentally retarded children:
- develop individual personalities and preferences;
- are no more likely to commit a crime than their peers;
- do not have difficulty bonding as children;
- ARE at increased risk for development of another mental disorder.
- do NOT necessarily have perceptual disturbances, violent or sexual ideation, or delusional thinking (they may, but it would be acccounted for by another diagnosis, not their mental retardation);.
- tend to be very concrete in their thinking and reasoning.
- go through milestones in normal ORDER, but often plateau at a lower than normal level.
Mental retardation has an onset before age 18 (normal cognitive functioning followed by a cognitive decline is dementia, not mental retardation).
DSM-IV, pages 39-46.