Childhood disintegrative disorder (historical Heller syndrome)

Childhood disintegrative disorder (CDD), also called Heller syndrome, is a historical diagnostic label for marked loss of previously acquired skills after a period of apparently typical early development. It is not a distinct diagnosis in DSM-5 or DSM-5-TR: those manuals place prior CDD presentations within autism spectrum disorder (ASD). ICD-11 also classifies current presentations within ASD and can specify loss of previously acquired skills.1

Developmental regression is a clinical finding, not a diagnosis by itself. It requires prompt evaluation because autism-related regression, epilepsy, hearing change, and genetic, metabolic, neurologic, or other medical conditions can overlap.3

What the historical label described

Older criteria described apparently typical development for at least the first two years, followed before age ten by clinically significant loss of skills in multiple areas. Reported losses could involve language, social or adaptive behavior, play, bowel or bladder control, or motor ability, together with autism-like social-communication differences and restricted or repetitive behavior.6

The historical description does not establish a single cause, a universal degenerative course, or a specific treatment. Published cohorts were small, and current diagnostic systems no longer treat CDD as a separate disease.17

If skills are being lost now

Document what changed, when it changed, whether the change was sudden or gradual, and what was happening medically or environmentally at the time. Arrange timely medical and developmental evaluation. New seizures, altered awareness, sudden weakness, breathing or swallowing difficulty, or rapid loss of function may require urgent care.

Assessment commonly starts with:

• a detailed developmental, medical, medication, family, and educational history;
• hearing, vision, neurologic, developmental, and communication assessment;
• review for seizures, sleep disruption, pain, illness, and loss of access to learned skills;
• genetic, metabolic, imaging, or electroencephalography testing only when the history and examination indicate it.

The American Academy of Pediatrics specifically advises against routine EEG for every autistic child; EEG is considered when seizures, atypical regression, or other neurologic findings raise concern.3

Support after regression

There is no proven medication or disease-modifying therapy specific to historical CDD. Treatment should address the diagnosed cause, co-occurring conditions, safety, learning, participation, and the person's present developmental profile. Educational, speech-language, occupational, physical, behavioral, mental-health, or family support may be appropriate, but no single program fits everyone.3

Communication and AAC

Do not wait for the diagnostic workup to finish before restoring reliable communication access. Record skills before and after the change and identify how the person currently communicates yes, no, stop, pain, comfort, preferences, and social messages.

An individualized communication assessment should:

• preserve useful speech, gesture, sign, writing, objects, pictures, and familiar signals;
• assess understanding separately from spoken output;
• consider motor planning, positioning, sensory access, fatigue, seizures, and performance across settings;
• trial touch, keyguards, switches, partner-assisted scanning, or eye gaze only when the person's performance supports them;
• provide trained communication partners and a low-tech backup.

There are no cognitive or age prerequisites for AAC, and AAC should supplement rather than remove effective existing communication.4 For the general evaluation, trial, funding, and implementation process, use the AAC device acquisition guide.

Coding

• ICD-10-CM F84.3: Other childhood disintegrative disorder. This is a retained U.S. billing label, not evidence that CDD is a current standalone DSM diagnosis.5
• ICD-11 6A02: Autism spectrum disorder. ICD-11 codes are selected using intellectual-development and functional-language specifiers and can add a qualifier for loss of previously acquired skills.2

6A02.3 is not a synonym for Heller syndrome. It means autism spectrum disorder with a disorder of intellectual development and impaired functional language.2

Sources

1. American Psychiatric Association: Autism spectrum disorder — DSM-5/DSM-5-TR terminology and subsuming of childhood disintegrative disorder.
2. World Health Organization: ICD-11 Clinical Descriptions and Diagnostic Requirements — current ASD classification, intellectual-development and functional-language specifiers, and the qualifier for loss of previously acquired skills.
3. Hyman et al. Identification, Evaluation, and Management of Children With Autism Spectrum Disorder — evaluation of regression and indication-based neurologic testing (American Academy of Pediatrics, 2020).
4. American Speech-Language-Hearing Association: Augmentative and Alternative Communication — individualized, multimodal AAC assessment and no-prerequisite guidance.
5. Centers for Medicare & Medicaid Services: FY 2026 ICD-10-CM definitions — current F84.3 descriptor.
6. Volkmar and Rutter. Childhood disintegrative disorder: results of the DSM-IV autism field trial — historical diagnostic framing and field-trial evidence (1995; PMID 7665448).
7. Mehra et al. Childhood disintegrative disorder and autism spectrum disorder: a systematic review — evidence limitations and characteristics of 96 reported participants (2019; PMID 30548847).

Review boundary

This guide cannot determine why a person lost skills or select tests and treatment. A developmental or neurologic clinician should review active regression, and an interdisciplinary team should translate findings into individualized communication and support plans.