Diagnostic Criteria for Autism Spectrum Disorder

Core Diagnostic Criteria

The American Academy of Child and Adolescent Psychiatry requires persistent deficits in social communication and social interaction across multiple contexts, plus restricted, repetitive patterns of behavior, interests, or activities, with symptoms present in the early developmental period 1, 2
Deficits in social-emotional reciprocity, nonverbal communicative behaviors, and developing, maintaining, and understanding relationships are required for a diagnosis of Autism Spectrum Disorder, according to the American Academy of Child and Adolescent Psychiatry 2

The American Academy of Child and Adolescent Psychiatry identifies stereotyped or repetitive motor movements, use of objects, or speech, insistence on sameness, inflexible adherence to routines, or ritualized patterns, highly restricted, fixated interests, and hyper- or hyporeactivity to sensory input or unusual interest in sensory aspects of environment as restricted, repetitive patterns of behavior 2

Symptoms of Autism Spectrum Disorder must be present in the early developmental period, although they may not become fully manifest until social demands exceed limited capacities, or may be masked by learned strategies in later life, as stated by the American Academy of Child and Adolescent Psychiatry 1, 2
The American Academy of Child and Adolescent Psychiatry requires that symptoms cause clinically significant impairment in social, occupational, or other important areas of current functioning 2

The American Academy of Child and Adolescent Psychiatry recommends specifying severity levels (Level 1, 2, or 3) separately for both social communication and restricted/repetitive behaviors, based on the amount of support required 3

The diagnostic stability of Autism Spectrum Disorder is well established in children aged 24 months and older, though diagnosis before 24 months may have higher false-positive rates, according to the American Academy of Child and Adolescent Psychiatry 2
A comprehensive multidisciplinary assessment must include direct observation using standardized measures, structured parent interviews, and cognitive and language assessment, as recommended by the American Academy of Child and Adolescent Psychiatry 2, 4

The American Academy of Child and Adolescent Psychiatry acknowledges that ASD symptoms "may be masked by learned strategies in later life," creating a diagnostic barrier because clinicians rely on observable behaviors that masking conceals, which can lead to delayed diagnosis and misdiagnosis 5, 6
The DSM-5 requires "clinically significant impairment in social, occupational, or other important areas of current functioning," but masking creates apparent functioning that conceals profound internal impairment and distress, making it essential to consider internal experience in diagnosis 5, 6
Comprehensive assessment must include structured parent interviews about early childhood behaviors before masking strategies developed, and direct observation using standardized measures like ADOS-2 should specifically assess for compensation by comparing observed social behavior against cognitive measures of social understanding 5, 6
The presence of exhaustion, burnout, anxiety, and depression in someone with subtle social differences should prompt consideration of masked ASD rather than dismissing ASD due to apparently adequate social functioning, as recommended by the American Academy of Child and Adolescent Psychiatry 5, 6

Belief systems and cultural factors impact screening and diagnosis outcomes, and families may not report differences if masking makes the child appear typical in clinical settings, highlighting the need for repeat screening at different ages to detect individuals missed on earlier occasions due to effective masking, as suggested by the American Academy of Pediatrics 5, 6
The heterogeneous presentation and time course of ASD deficits necessitates repeat screening at different ages to detect individuals missed on earlier occasions due to effective masking, which can help reduce missed diagnoses and improve diagnostic accuracy 5, 6

The American Academy of Child and Adolescent Psychiatry defines Autism Spectrum Disorder as requiring two core symptom domains – (1) persistent deficits in social communication and interaction across multiple contexts, and (2) restricted, repetitive patterns of behavior, interests, or activities, with symptoms present in the early developmental period and causing clinically significant impairment. 7

The American Academy of Child and Adolescent Psychiatry states that symptoms must be present in the early developmental period, although they may not become fully manifest until social demands exceed the individual’s limited capacities. 7
The Academy notes that the previous DSM‑IV requirement of onset before age 3 years was changed to “early developmental period” to provide greater diagnostic flexibility. 7

The American Academy of Child and Adolescent Psychiatry recommends documenting the presence or absence of the following specifiers when diagnosing ASD: