A comparative study of development and symptoms among disintegrative psychosis and infantile autism with and without speech loss.

Doctors watched a small group of children who lost skills after age three. They compared two kinds of kids: those with disintegrative psychosis and those with infantile autism who also lost speech.

The team wrote down each child’s early growth, the age skills vanished, and later test scores. No treatment was given; they simply tracked what happened.

Children with disintegrative psychosis ended up with lower thinking scores than the autism-plus-speech-loss group. The drop was large enough to suggest the two labels point to different roads.

Kurita et al. (2004) tried the same comparison twelve years later. They found no short-term IQ gap, so the picture is muddy. Their kids were tested sooner, which may hide the late decline H et al. saw.

Warnes et al. (2005) looked only at autism and said skill loss does not predict later scores. That seems to clash, but they excluded disintegrative psychosis. Once you separate the rare, late-loss kids from plain autism, the worse outcome returns.

Bhaumik et al. (2009) widened the lens: across all PDD, about one in five lose skills. Their work shows regression is common, while H et al. remind us the rare, late form is the most damaging.

When parents say, “My child was typical, then everything stopped at four,” flag it. Ask for a full cognitive battery and plan for more support than you would for early-onset autism. Share the Hiroshi paper with families to show why short-term scores can look hopeful yet still dip later.