High overlap
OCD is more common in autistic and children than in the general population. Studies suggest:
- Around 17–37% of autistic people also have OCD
- and OCD co-occur more than chance would predict
- All three conditions share difficulties with anxiety, rigidity, and impulse control
Why the overlap happens
- Executive function differences – planning, inhibition, and shifting attention are affected in all three
- Intolerance of uncertainty – common in autism and OCD
- Sensory sensitivities – can drive compulsions (e.g. washing to remove a "contaminated" feeling)
- Repetitive behaviours – stimming can look like compulsions, and vice versa
Telling them apart
| Autism / Stimming | OCD Compulsion |
|---|---|
| Usually enjoyable or regulating | Driven by anxiety or fear |
| Done freely | Feels forced or "must do" |
| Stops when satisfied | Must be done "right" or repeated |
| Child is calm during | Child is anxious until finished |
Diagnostic challenges
- Clinicians may miss OCD in autistic children because they assume behaviours are "just autism"
- symptoms (impulsivity, inattention) can mask OCD rituals
- Anxiety disorders and OCD are often confused
What to ask the assessor
- "Are you screening for OCD as well as autism/?"
- "Can these repetitive behaviours be both stimming and compulsions?"
- "What treatment would you recommend if both are present?"
Treatment when both are present
- CBT for OCD can be adapted for autistic children (slower pace, more visuals, concrete examples)
- ERP (Exposure and Response Prevention) may need adjusting if your child has sensory needs
- Medication (SSRIs) can help OCD symptoms and is generally safe with autism/
- Occupational Therapy can address sensory drivers of compulsions