DSM-5 Diagnostic Criteria for Autism Spectrum Disorder
The DSM-5 requires persistent deficits in social communication and social interaction across multiple contexts (Criterion A), plus restricted, repetitive patterns of behavior, interests, or activities (Criterion B), with symptoms present in the early developmental period (Criterion C). 1
Core Diagnostic Criteria
Criterion A: Social Communication and Social Interaction Deficits
All three of the following must be present 1:
Deficits in social-emotional reciprocity - ranging from abnormal social approach and failure of normal back-and-forth conversation, to reduced sharing of interests, emotions, or affect, to complete failure to initiate or respond to social interactions 1, 2
Deficits in nonverbal communicative behaviors - ranging from poorly integrated verbal and nonverbal communication, to abnormalities in eye contact and body language or deficits in understanding and use of gestures, to total lack of facial expressions and nonverbal communication 1, 3
Deficits in developing, maintaining, and understanding relationships - ranging from difficulties adjusting behavior to suit various social contexts, to difficulties in sharing imaginative play or making friends, to absence of interest in peers 1, 3
Criterion B: Restricted, Repetitive Patterns of Behavior
At least two of the following four must be present 1:
Stereotyped or repetitive motor movements, use of objects, or speech - including simple motor stereotypies, lining up toys, echolalia, or idiosyncratic phrases 1
Insistence on sameness, inflexible adherence to routines, or ritualized patterns - including extreme distress at small changes, difficulties with transitions, rigid thinking patterns, or need to take same route or eat same food daily 1
Highly restricted, fixated interests that are abnormal in intensity or focus - such as strong attachment to or preoccupation with unusual objects, or excessively circumscribed or perseverative interests 1
Hyper- or hyporeactivity to sensory input or unusual interest in sensory aspects of environment - including apparent indifference to pain/temperature, adverse response to specific sounds or textures, excessive smelling or touching of objects, or visual fascination with lights or movement 1
Additional Required Criteria
Criterion C: Early Developmental Period
Symptoms 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 1
Criterion D: Functional Impairment
Symptoms must cause clinically significant impairment in social, occupational, or other important areas of current functioning 1
Criterion E: Exclusion Criteria
The disturbances are not better explained by intellectual disability or global developmental delay, though ASD and intellectual disability frequently co-occur 1, 3
Severity Specification Requirements
Clinicians must specify severity levels (Level 1,2, or 3) separately for both Criterion A (social communication) and Criterion B (restricted/repetitive behaviors), based on the amount of support required. 3
- Level 3 ("Requiring very substantial support") - Severe deficits causing severe impairments in functioning 3
- Level 2 ("Requiring substantial support") - Marked deficits with noticeable impairments even with support in place 3
- Level 1 ("Requiring support") - Without supports in place, deficits cause noticeable impairments 3
Important Clinical Considerations
Diagnostic Stability and Age
The diagnostic stability of ASD is well established in children aged 24 months and older, though diagnosis before 24 months may have higher false-positive rates 4. Between 12 and 24 months, key markers include reduced social attention and social communication, along with increased repetitive behavior with objects 2.
Assessment Requirements
A comprehensive multidisciplinary assessment must include direct observation using standardized measures such as the Autism Diagnostic Observation Schedule (ADOS), structured parent interviews, and cognitive and language assessment 2, 3. Hearing should be formally assessed with an audiogram to rule out hearing loss that could mimic ASD symptoms 2.
Common Pitfalls to Avoid
The distinction between ASD and developmental language disorders is particularly difficult in preschool children, but two behaviors consistently differentiate autistic children from language-impaired peers at 20 and 42 months: pointing for interest and use of conventional gestures 1. Similarly, differentiating mild to moderate developmental delay from ASD may be difficult, particularly in younger children, but items like use of other's body, attention to voice, pointing, and finger mannerisms help distinguish these conditions at 36 months 1.