The two core domains
The DSM-5-TR (American Psychiatric Association, 2022) defines autism by persistent differences in two domains, present from early development:
A. Social communication and interaction
All three must be present:
- Differences in social-emotional reciprocity (back-and-forth conversation, sharing interests/emotions).
- Differences in nonverbal communication (eye contact, gestures, facial expression).
- Differences in developing, maintaining, and understanding relationships.
B. Restricted, repetitive patterns
At least two of:
- Repetitive motor movements, speech, or use of objects (stimming, echolalia, lining up).
- Insistence on sameness, routines, or ritualized behavior.
- Highly restricted, intense interests.
- Hyper- or hypo-reactivity to sensory input, or unusual sensory interest.
Support levels
The DSM-5 specifies how much support a person needs in each domain:
- Level 1 — "Requiring support"
- Level 2 — "Requiring substantial support"
- Level 3 — "Requiring very substantial support"
Support needs can change over time and across environments. A person may be Level 1 socially but Level 2 in sensory regulation, or be Level 1 in a familiar setting and Level 3 in a chaotic one.
What changed in DSM-5
Previous DSM-IV diagnoses (Asperger's, PDD-NOS, autistic disorder) were consolidated into a single Autism Spectrum Disorder diagnosis in 2013.
Limits of the criteria
The DSM-5 criteria were validated mostly on young white boys. They under-identify:
- Girls and women (who often mask)
- Adults seeking later diagnosis
- People of color, who are diagnosed later on average (CDC, 2023)
- People with a PDA (Pathological/Persistent Demand Avoidance) profile
An experienced clinician will look beyond the checklist.