External validity of childhood disintegrative disorder in comparison with autistic disorder.

Kurita et al. (2004) compared two groups of children: kids with childhood disintegrative disorder (CDD) and kids with autistic disorder (AD).

They looked at short-term thinking skills, epilepsy rates, and IQ patterns.

The study used a case-control design, matching the groups on age and other traits.

Both groups scored about the same on short-term cognitive tests.

The CDD group had more epilepsy, but their IQ scores were less uneven than the AD group.

In plain words: right after regression, CDD kids did not look worse than AD kids on thinking tasks.

Charlop et al. (1992) saw "greater later retardation" in disintegrative psychosis, but that study was small and had no control group.

Kurita et al. (2004) used tighter matching and found no short-term cognitive gap, updating the earlier view.

Lindsley (1992) first argued CDD deserved its own DSM label; Hiroshi et al. later gave the real-world evidence that the label holds up.

Kahng et al. (1999) called for more CDD research; this 2004 paper answered with hard data.

If a child regresses after age three, do not assume instant severe cognitive loss.

Plan assessments and goals the same way you would for a child with classic autism, but watch for seizures.

Use the CDD diagnosis when you see late regression; it is valid and insurance will accept it.