CDD is the strangest and most unsettling developmental condition you have probably never heard of. Also known as Heller’s syndrome, for the Austrian special educator who first described it in 1908, it is a late-blooming, viciously regressive form of autism. It’s rare, striking about 1 or 2 in every 100,000 children. After developing typically for two to ten years (the average is three or four), a child with CDD will suffer deep, sharp reversals along multiple lines of development, which may include language, social skills, play skills, motor skills, cognition and bladder or bowel control.
The speed and character of this reversal varies, but it often occurs in a horrifyingly short period — as short as a couple of months, says Gupta. In about 75 percent of cases, this loss of skills is preceded by days or weeks in which the child experiences intense anxiety and even terror: nightmares and waking nightmares and bouts of confused, jumpy disturbance that resemble psychosis. (In the 1970s and 1980s, the diagnostic term used for CDD in many countries was ‘disintegrative psychosis.’) During this anxiety-ridden prologue, known as a ‘prodrome,’ a child will often seem keenly aware that something is wrong. He’ll say he’s scared. He’ll pace and hold his head and say it hurts. As the increasingly frightened parents watch, he loses speech, motor skills, and most means of social contact. It is as if something is erasing everything he has become.