Diagnostic Criteria of ASD

DSM-5 Diagnostic Criteria for Autism Spectrum Disorder

Criterion A: Social Communication and Social Interaction Deficits

All THREE of the following must be present (currently or by history):

A1. Deficits in Social-Emotional Reciprocity:

Examples:

  • Abnormal social approach
  • Failure of normal back-and-forth conversation
  • Reduced sharing of interests, emotions, or affect
  • Failure to initiate or respond to social interactions
  • One-sided conversations
  • Difficulty understanding social nuances

Manifestations:

  • Not initiating interactions
  • Inappropriate social approach (too formal, too familiar)
  • Difficulty maintaining conversation flow
  • Limited response to others’ social overtures
  • Appears disinterested in others

A2. Deficits in Nonverbal Communicative Behaviors:

Examples:

  • Poorly integrated verbal and nonverbal communication
  • Abnormalities in eye contact and body language
  • Deficits in understanding and use of gestures
  • Total lack of facial expressions and nonverbal communication

Manifestations:

  • Limited or absent eye contact
  • Unusual facial expressions or lack thereof
  • Difficulty interpreting others’ nonverbal cues
  • Limited use of gestures (pointing, waving, nodding)
  • Monotone or unusual voice tone/pitch
  • Rigid or unusual body posture

A3. Deficits in Developing, Maintaining, and Understanding Relationships:

Examples:

  • Difficulties adjusting behavior to suit various social contexts
  • Difficulties in sharing imaginative play or making friends
  • Absence of interest in peers

Manifestations:

  • Difficulty forming age-appropriate friendships
  • Limited interest in peers (prefers adults or younger children)
  • Problems with imaginative/pretend play
  • Difficulty understanding social rules and norms
  • Inappropriately formal or familiar with different people
  • Preference for solitary activities
  • Limited understanding of relationships

Severity: Specify current severity based on level of support needed due to social communication impairments

Criterion B: Restricted, Repetitive Patterns of Behavior, Interests, or Activities

At least TWO of the following must be present (currently or by history):

B1. Stereotyped or Repetitive Motor Movements, Use of Objects, or Speech:

Motor Stereotypies:

  • Hand flapping
  • Body rocking
  • Spinning in circles
  • Toe walking
  • Finger flicking

Object Use:

  • Lining up toys
  • Spinning wheels repeatedly
  • Flipping objects
  • Unusual attachment to specific objects

Speech:

  • Echolalia: Repeating words or phrases heard (immediate or delayed)
  • Idiosyncratic phrases: Personal phrases used repetitively
  • Scripting: Repeating lines from movies, books
  • Repetitive questioning

B2. Insistence on Sameness, Inflexible Adherence to Routines, or Ritualized Patterns:

Examples:

  • Extreme distress at small changes
  • Difficulties with transitions
  • Rigid thinking patterns
  • Greeting rituals
  • Need to take same route or eat same food daily

Manifestations:

  • Meltdowns when routine disrupted
  • Must follow specific sequences (morning routine, meals)
  • Ritualized patterns of verbal/nonverbal behavior
  • Extreme distress at trivial changes
  • Difficulty with flexibility
  • Need for predictability and control

B3. Highly Restricted, Fixated Interests Abnormal in Intensity or Focus:

Examples:

  • Strong attachment to unusual objects
  • Excessively circumscribed or perseverative interests

Manifestations:

  • Intense preoccupation with specific topics (trains, weather, dates)
  • Encyclopedic knowledge in narrow areas
  • Talking exclusively about specific interests
  • Difficulty shifting attention from interest
  • Collecting information/objects about interest obsessively
  • Unusual objects of interest (vacuum cleaners, ceiling fans)

B4. Hyper- or Hyporeactivity to Sensory Input or Unusual Interest in Sensory Aspects:

Hyperreactivity (Over-sensitive):

  • Covers ears at normal sounds
  • Distress at certain textures, clothing tags
  • Avoids certain food textures
  • Bothered by lights, fluorescent lighting
  • Distressed by smells others don’t notice

Hyporeactivity (Under-sensitive):

  • Apparent indifference to pain or temperature
  • Doesn’t respond to name being called
  • High pain threshold
  • Seeks intense sensory input

Unusual Interest:

  • Excessive smelling or touching of objects
  • Visual fascination with lights or movement
  • Seeking proprioceptive input (crashing, jumping)
  • Fascination with spinning objects

Severity: Specify current severity based on level of support needed due to restricted, repetitive behaviors

Criterion C: Early Developmental Period

Symptoms must be present in early developmental period

However:

  • May not become fully manifest until social demands exceed capacities
  • May be masked by learned strategies in later life
  • Can be diagnosed in adulthood if developmental history supports early presence

Typical Recognition:

  • Many identified by age 2-3
  • Some not recognized until school age or later
  • Higher-functioning individuals may not be diagnosed until adolescence/adulthood

Criterion D: Functional Impairment

Symptoms cause clinically significant impairment in:

  • Social functioning
  • Occupational functioning
  • Other important areas of current functioning

Must interfere with life: Not just present, but causing problems

Criterion E: Exclusion

Disturbances are not better explained by:

  • Intellectual Disability (Intellectual Developmental Disorder)
  • Global Developmental Delay

However: ASD and intellectual disability frequently co-occur; diagnose both if:

  • Social communication is below expected for general developmental level

Specify Current Severity Level

Based on social communication impairments and restricted, repetitive patterns of behavior:

Level 3: “Requiring Very Substantial Support”

Social Communication:

  • Severe deficits in verbal and nonverbal social communication
  • Very limited initiation of social interactions
  • Minimal response to social overtures from others
  • May be nonverbal or minimally verbal

Restricted/Repetitive Behaviors:

  • Inflexibility of behavior
  • Extreme difficulty coping with change
  • Restricted/repetitive behaviors markedly interfere with functioning in all spheres
  • Great distress/difficulty changing focus or action

Support Needs: Requires substantial support in daily life

Level 2: “Requiring Substantial Support”

Social Communication:

  • Marked deficits in verbal and nonverbal social communication
  • Social impairments apparent even with supports in place
  • Limited initiation of social interactions
  • Reduced or abnormal responses to social overtures from others
  • Speech may be present but atypical

Restricted/Repetitive Behaviors:

  • Inflexibility of behavior
  • Difficulty coping with change
  • Restricted/repetitive behaviors appear frequently enough to be obvious
  • Distress/difficulty changing focus or action

Support Needs: Requires substantial support in daily life

Level 1: “Requiring Support”

Social Communication:

  • Without supports, social communication deficits cause noticeable impairments
  • Difficulty initiating social interactions
  • Atypical or unsuccessful response to social overtures of others
  • May appear to have decreased interest in social interactions
  • Can speak in full sentences and engage in communication

Restricted/Repetitive Behaviors:

  • Inflexibility of behavior causes significant interference with functioning in one or more contexts
  • Difficulty switching between activities
  • Problems of organization and planning hamper independence

Support Needs: Requires support; without it, impairments noticeable

Specify If:

With or Without Accompanying Intellectual Impairment

With or Without Accompanying Language Impairment:

  • Note level of language functioning (nonverbal to fluent)

Associated With:

  • Known genetic or other medical condition
  • Environmental factor
  • Another neurodevelopmental, mental, or behavioral disorder
  • Catatonia

Changes from DSM-IV to DSM-5

Major Changes:

  1. Single Spectrum: Combined Autistic Disorder, Asperger’s, PDD-NOS into one diagnosis

  2. Two Core Domains (instead of three):

    • Social communication/interaction (combined from two separate domains)
    • Restricted/repetitive behaviors

  3. All Criteria Must Be Met: More stringent diagnosis

  4. Sensory Issues Added: Now part of diagnostic criteria (B4)

  5. Severity Levels: Three levels based on support needs

  6. Can Co-diagnose with ADHD: Previously excluded

  7. Asperger’s Eliminated: Now all fall under ASD spectrum

Associated Features

Commonly Co-occurring:

  • Intellectual disability (30-40%)
  • Language impairment (25-30% minimally verbal)
  • ADHD symptoms (40-70%)
  • Anxiety (40-50%)
  • Depression (especially adolescence/adulthood)
  • Epilepsy (20-30%)
  • Sleep disturbances (50-80%)
  • Gastrointestinal problems
  • Motor coordination problems

Strengths (individual variation):

  • Attention to detail
  • Strong memory for specific information
  • Visual/spatial skills
  • Pattern recognition
  • Honesty and directness
  • Logical thinking in interest areas

Assessment Requirements

Comprehensive Evaluation Includes:

  1. Developmental History:

    • Early developmental milestones
    • Age of first words, first phrases
    • Social development
    • Regression (if any)

  2. Autism-Specific Assessments:

    • ADOS-2 (Autism Diagnostic Observation Schedule): Gold standard observational assessment
    • ADI-R (Autism Diagnostic Interview-Revised): Parent interview
    • M-CHAT (screening tool for toddlers)

  3. Cognitive Assessment: IQ testing to determine if intellectual disability present

  4. Language Assessment: Speech and language evaluation

  5. Adaptive Behavior Assessment: Functional skills in daily life

  6. Medical Evaluation:

    • Hearing test (rule out hearing loss)
    • Genetic testing (if indicated)
    • EEG (if seizures suspected)
    • Medical examination

  7. Behavioral Observations: Multiple settings, situations

  8. Comorbidity Screening: ADHD, anxiety, depression

Differential Diagnosis

Must Distinguish From:

Social (Pragmatic) Communication Disorder: Social communication deficits WITHOUT restricted/repetitive behaviors

Intellectual Disability: If social communication appropriate for developmental level

ADHD: Social problems from inattention/impulsivity, not social communication deficits

Language Disorders: Language problems without broader ASD features

Selective Mutism: Speaks in some situations, mute in others (anxiety-based)

Attachment Disorders: From severe neglect; improves with appropriate care

Schizophrenia: Later onset, hallucinations/delusions present

Red Flags in Early Development

12-24 Months:

  • No babbling by 12 months
  • No gestures (pointing, waving) by 12 months
  • No single words by 16 months
  • No two-word phrases by 24 months
  • Loss of previously acquired language or social skills
  • Limited eye contact
  • No response to name
  • Limited interest in other children

Any Age:

  • No social smile
  • Preference for being alone
  • Unusual ways of playing with toys
  • Extreme resistance to change
  • Unusual sensory responses

Key Diagnostic Points for Exams

  1. Two core domains: Social communication/interaction deficits + restricted/repetitive behaviors
  2. All three A criteria must be met (all social/communication deficits)
  3. At least two B criteria must be met (restricted/repetitive behaviors)
  4. Present in early development (even if masked or not recognized)
  5. Causes functional impairment in daily life
  6. Three severity levels based on support needs (1, 2, 3)
  7. Spectrum disorder: Wide range of presentations and severities
  8. Sensory issues now part of diagnostic criteria
  9. Can co-occur with intellectual disability, ADHD, others
  10. Comprehensive assessment required with specialized tools (ADOS-2, ADI-R)