What are the DSM‑5 (Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition) diagnostic criteria for autism spectrum disorder?

DSM-5 Diagnostic Criteria for Autism Spectrum Disorder

Autism spectrum disorder requires two core symptom domains: (1) persistent deficits in social communication and social interaction across multiple contexts, and (2) restricted, repetitive patterns of behavior, interests, or activities, with symptoms present in the early developmental period causing clinically significant impairment. 1, 2

Core Domain 1: Social Communication and Interaction Deficits

All three of the following must be present 2, 3:

• 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 2, 3

• Deficits in nonverbal communicative behaviors — ranging from poorly integrated verbal and nonverbal communication to abnormalities in eye contact and body language, to deficits in understanding and use of gestures, to total lack of facial expressions and nonverbal communication 2, 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 2, 3

Core Domain 2: Restricted, Repetitive Patterns of Behavior

At least two of the following four must be present 2, 3:

• Stereotyped or repetitive motor movements, use of objects, or speech — including simple motor stereotypies, lining up toys or flipping objects, echolalia, or idiosyncratic phrases 2

• Insistence on sameness, inflexible adherence to routines, or ritualized patterns — including extreme distress at small changes, difficulties with transitions, rigid thinking patterns, greeting rituals, or need to take same route or eat same food daily 2

• 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 2

• 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 2

Additional Required Criteria

Timing and developmental considerations 1, 2:

• Symptoms must be present in the early developmental period, though they may not become fully manifest until social demands exceed limited capacities 1, 2
• Symptoms may be masked by learned strategies in later life, particularly in individuals who develop compensatory mechanisms 2
• The strict DSM-IV requirement for onset before age 3 years was changed to "early developmental period" to allow for diagnostic flexibility 1

Functional impairment requirement 2, 3:

• Symptoms must cause clinically significant impairment in social, occupational, or other important areas of current functioning 2
• This criterion can be challenging when masking is present, as apparent functioning may conceal profound internal impairment and distress 2

Exclusion criteria 3:

• The disturbances are not better explained by intellectual disability or global developmental delay, though ASD and intellectual disability frequently co-occur 3

Severity Specification

Specify current severity level separately for each core domain (social communication and restricted/repetitive behaviors) based on the amount of support required 2:

• Level 3: "Requiring very substantial support" — severe deficits causing severe impairments in functioning 2
• Level 2: "Requiring substantial support" — marked deficits with noticeable impairments even with support in place 2
• Level 1: "Requiring support" — noticeable difficulties without support, but able to function with assistance 2

Additional Diagnostic Specifiers

Document the presence or absence of 1, 2:

• Accompanying intellectual impairment 1
• Accompanying language impairment 1
• Associated with a known medical, genetic, or environmental factor 1
• Associated with another neurodevelopmental, mental, or behavioral disorder 1
• With catatonia 1

Critical Diagnostic Considerations

Diagnostic stability and timing 2, 4:

• Diagnosis is well-established and stable in children aged 24 months and older 2
• Diagnosis before 24 months may have higher false-positive rates, though early evaluation is justified when concerns exist 2

Masking and compensation 2:

• The presence of exhaustion, burnout, anxiety, and depression in someone with subtle social differences should prompt consideration of masked ASD rather than dismissing the diagnosis due to apparently adequate social functioning 2
• Assessment must include structured parent interviews about early childhood behaviors before masking strategies developed 2
• Direct observation should specifically assess for compensation by comparing observed social behavior against cognitive measures of social understanding 2

Common early signs in the first 2 years 3:

• No response to name when called 3
• No or limited use of gestures in communication 3
• Lack of imaginative play 3

Required assessment components 2, 4, 3:

• Direct observation using standardized measures such as the Autism Diagnostic Observation Schedule-Second Edition (ADOS-2), which has 91% sensitivity and 76% specificity 2, 4, 3
• Structured parent interview using tools like the Autism Diagnostic Interview-Revised (ADI-R), which has 80% sensitivity and 72% specificity 4, 3
• Cognitive and language assessment across all domains 2, 4
• Adaptive functioning evaluation 4

Key diagnostic pitfalls to avoid 4:

• Relying on screening tools alone for diagnosis — screening identifies risk but cannot establish diagnosis 4
• Single-provider evaluation — comprehensive multidisciplinary assessment is required 4
• Diagnostic overshadowing — failing to recognize ASD when other conditions are present 4
• Dismissing ASD diagnosis based on apparently adequate social functioning without considering masking 2