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Guide des troubles cliniques

Autism
Spectrum Disorder

A neurodevelopmental condition characterized by persistent differences in social communication, restricted interests, repetitive behaviors, and atypical sensory processing. Presents across a spectrum of support needs.

1 in 36
Prévalence
~18mo
Âge d'apparition
4:1
Ratio
70-90%
Taux de réponse

Critères diagnostiques du DSM-5-TR

Criterion A: Social Communication & Interaction Deficits

Persistent deficits across multiple contexts. All three required:

  • • Social-Emotional Reciprocity (Abnormal social approach, reduced sharing of interests/emotions, failure to initiate/respond to social interactions)
  • • Nonverbal Communication (Poorly integrated verbal/nonverbal communication, abnormal eye contact and body language, deficits in understanding/using gestures)
  • • Relationships (Difficulty adjusting behavior to social contexts, challenges in sharing imaginative play, difficulty making friends, absence of interest in peers)

Criterion B: Restricted, Repetitive Behaviors

2+ required:

  • • Stereotyped/Repetitive Motor Movements or Speech (Hand flapping, rocking, echolalia, idiosyncratic phrases)
  • • Insistence on Sameness (Inflexible routines, ritualized patterns, extreme distress at changes)
  • • Highly Restricted, Fixated Interests (Abnormal in intensity or focus)
  • • Atypical Sensory Responses (Hyper/hypo-reactivity, unusual sensory interests, adverse response to textures/sounds)

Criterion C & D: Development & Function

Onset and impact requirements:

  • • Criterion C: Symptoms must be present in early childhood
  • • Criterion D: Symptoms cause clinically significant impairment in social, occupational, or other areas

Specifiers

Additional diagnostic information:

  • • With or without intellectual impairment
  • • With or without language impairment
  • • Associated with known genetic/medical condition
  • • Level of support required (Level 1, 2, or 3)

Protocoles d'évaluation

Outils validés pour le dépistage et le suivi de la sévérité

ADOS-2

Autism Diagnostic Observation Schedule, Second Edition

Criterion-standard semi-structured assessment using standardized activities to observe social-communication and restricted/repetitive behaviors.

Cotation :

Comparison scores (1-10); scores ≥8 suggest autism, 4-7 autism spectrum; module selected by age/language level

Durée :40-60 minutes

ADI-R

Autism Diagnostic Interview-Revised

Detailed parent/caregiver interview covering developmental history and current behaviors; complements ADOS-2.

Cotation :

Algorithm scores for social interaction, communication, and restricted/repetitive behaviors

Durée :90-150 minutes

M-CHAT-R/F

Modified Checklist for Autism in Toddlers, Revised with Follow-Up

Parent questionnaire for screening toddlers (16-30 months); includes follow-up interview to reduce false positives.

Cotation :

Low, medium, high risk based on critical items; high risk warrants immediate diagnostic evaluation

Durée :5 minutes (screener), 5-10 minutes (follow-up)

SRS-2

Social Responsiveness Scale, Second Edition

Quantitative measure of autistic traits across social awareness, cognition, communication, motivation, and restricted/repetitive behaviors.

Cotation :

T-scores: ≥76 severe, 66-75 moderate, 60-65 mild deficits in social interaction

Durée :15-20 minutes

Causes et étiologie

Neurobiological

  • Atypical brain connectivity (reduced long-range, increased local)
  • Brain volume changes in early childhood
  • Abnormalities in temporal cortex, amygdala, cerebellum
  • Altered excitatory/inhibitory (E/I) balance

Genetic

  • Heritability: 70-90%
  • Polygenic architecture: 100+ genes
  • De novo mutations (SHANK3, NLGN, NRXN)
  • Copy number variants (16p11.2 deletion, 15q duplication)

Environmental

  • Advanced parental age
  • Prenatal exposure to valproate
  • Maternal immune activation
  • Extreme prematurity and low birth weight

Neuropsychological

  • Theory of Mind deficits
  • Weak central coherence
  • Executive function impairments
  • Atypical sensory processing
Fondé sur des données probantes

Sources scientifiques

ADOS-2 Validation

Lord C, Rutter M, et al. Autism Diagnostic Observation Schedule, Second Edition (ADOS-2) Manual. Western Psychological Services. 2012.

DSM-5-TR Criteria

American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, Text Revision (DSM-5-TR). 2022.

Early Intensive Behavioral Intervention

Dawson G, Rogers S, et al. Randomized, controlled trial of an intervention for toddlers with autism: the Early Start Denver Model. Pediatrics. 2010;125(1):e17-23.

Genetic Architecture of Autism

Grove J, Ripke S, et al. Identification of common genetic risk variants for autism spectrum disorder. Nat Genet. 2019;51(3):431-444.

Neurobiology of Autism

Geschwind DH, Levitt P. Autism spectrum disorders: developmental disconnection syndromes. Curr Opin Neurobiol. 2007;17(1):103-111.

M-CHAT-R/F Screening Tool

Robins DL, Casagrande K, et al. Validation of the Modified Checklist for Autism in Toddlers, Revised with Follow-up (M-CHAT-R/F). Pediatrics. 2014;133(1):37-45.

Recherche et actualités sur ASD Clinical Guide: ADOS-2, M-CHAT and DSM-5-TR Criteria

Nouvelles, recherches et politiques récentes provenant de sources fiables.