Diagnosis of autism

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Autism spectrum disorder (ASD) is diagnosed through observed and reported behavior; no biological or genetic markers currently allow for a definitive diagnosis. Clinicians base assessments on standardized behavioral criteria defined in the International Classification of Diseases (ICD) of the World Health Organization and the Diagnostic and Statistical Manual of Mental Disorders (DSM) of the American Psychiatric Association. [1]

Contents

The DSM-5 (2013) unified earlier subtypes such as Asperger syndrome under a single autism spectrum diagnosis, while the DSM-5-TR (2022) maintained this framework with clarifying revisions. The ICD-10 (1994) has been superseded by the ICD-11 (2022), which aligns closely with DSM-5 definitions and is now being adopted internationally. [2] [3]

According to the DSM-5-TR, ASD is characterized by:

  1. Persistent deficits in social communication and social interaction across contexts, and
  2. Restricted, repetitive patterns of behavior, interests, or activities.

Symptoms must appear in early development, cause significant functional impairment, and not be better explained by intellectual disability or global developmental delay. [2] [4] [5] [6] [7] [8] [9]

Diagnostic challenges

Process for screening and diagnosing ASD; M-CHAT is Modified Checklist for Autism in Toddlers; (+) is positive test result; (-) is negative test result Autism diagnostic process.png
Process for screening and diagnosing ASD; M-CHAT is Modified Checklist for Autism in Toddlers; (+) is positive test result; (−) is negative test result

Several factors make autism spectrum disorder (ASD) difficult to diagnose. There are no standardized imaging, molecular, or genetic tests that can confirm ASD. [10] Moreover, ASD presents with wide individual variation. Its behavioral characteristics differ depending on developmental stage, age of presentation, gender, level of support, and personal variability. [11] [12] ASD can also resemble several other conditions, including intellectual disability, hearing impairment, a specific language impairment [13] such as Landau–Kleffner syndrome, [14] ADHD, anxiety disorder, and psychotic disorders. [15] Furthermore, the presence of autism can make it harder to diagnose cooccurring psychiatric disorders such as depression. [16] Diagnosing ASD in adults poses additional difficulties, as many undiagnosed individuals have developed masking techniques which make recognition of symptoms challenging.

DSM-5-TR criteria

The DSM-5-TR lists five criteria (with examples) which include two groups of criteria (the first two): [12]

Diagnostic process

Ideally, the diagnosis of autism spectrum disorder (ASD) is made by a team of clinicians—such as pediatricians, medical specialists, psychologists, therapists and neurologists—based on information from the affected individual, caregivers, educators, other medical professionals, and direct observation. [17]

The age at which ASD is diagnosed varies. Some children can be diagnosed as early as 18 months, although diagnoses before age two are less reliable. [10] Diagnostic stability increases over the first three years of life; for example, a one-year-old who meets criteria is less likely than a three-year-old to do so later. [18] More severe forms of ASD are usually identified earlier. [19] Delays in appointment scheduling and the cost of care can also postpone diagnosis. [20]

Screening usually begins with a pediatrician or primary care physician taking a developmental history and performing a physical examination. If concerns arise, the physician may refer the individual for assessment to an ASD specialist who evaluates cognitive, communication, and family factors using standardized tools while considering any associated medical conditions. [13] A pediatric neuropsychologist may also assess behavior and cognitive abilities to support diagnosis and guide educational planning. [21]

After diagnosis, additional testing may be performed. A clinical genetics evaluation is often recommended when symptoms suggest a genetic cause. [22] Although up to 40% of ASD cases are linked to genetic factors, [23] comprehensive genetic testing is not routinely recommended. Current U.S. and U.K. guidelines limit testing to high-resolution chromosome and fragile X analysis. [22] Metabolic and neuroimaging tests are also not routinely used for diagnosis. [22]

In the United Kingdom, the National Autism Plan for Children recommends that diagnosis be completed within 30 weeks of first concern, though few assessments meet this target. [13] Increased awareness, broader diagnostic criteria, and improved access to care have contributed to more adults receiving ASD diagnoses. Diagnosing adults poses unique challenges because it relies on accurate developmental histories and may be complicated by coping strategies—known as "masking" or "camouflaging"—that conceal symptoms. [24] [25]

Presentation and diagnosis can also vary by sex and gender. Most studies have not clearly distinguished between biological and social factors. [26] Evidence suggests that autistic girls and women tend to display fewer repetitive behaviors and more camouflaging than males, [27] [28] often by imitating typical facial expressions or eye contact. [28] These differences, along with gender stereotypes, can delay or obscure diagnosis in females. [26] [27] As a result, many autistic women are diagnosed late, misdiagnosed, or remain undiagnosed. [27]

Because ASD diagnosis relies on behavioral observation, several professional organizations have published practice parameters. The American Academy of Neurology released guidelines in 2000, [29] followed by the American Academy of Child and Adolescent Psychiatry in 1999, [11] and a multi-society consensus panel the same year. [29] These recommend initial screening by general practitioners (Level 1) and a comprehensive evaluation by experienced clinicians (Level 2). They also emphasize a developmental framework, input from multiple informants such as parents and teachers, and a multidisciplinary team including clinical psychologists, neuropsychologists, and psychiatrists. [30]

As of 2019, psychologists typically wait until a child exhibits early signs of ASD before administering standardized assessment tools. [30] The Autism Diagnostic Interview-Revised (ADI-R) and Autism Diagnostic Observation Schedule (ADOS) are considered the gold-standard instruments for diagnosis. [31] [32] The ADI-R is a structured parent interview that explores current and past behavior, while the ADOS directly observes social and communication behaviors through interactive tasks. Other tools, such as the Childhood Autism Rating Scale, Autism Treatment Evaluation Checklist, and cognitive tests like the Peabody Picture Vocabulary Test, are often part of a full assessment battery. The Diagnostic Interview for Social and Communication Disorders (DISCO) may also be used. [33]

Screening

About half of parents of children with ASD notice their child's atypical behaviors by age 18 months, and about four-fifths notice by age 24 months. [18] If a child does not meet any of the following milestones, it "is an absolute indication to proceed with further evaluations. Delay in referral for such testing may delay early diagnosis and treatment and affect the [child's] long-term outcome." [29]

The Japanese practice is to screen all children for ASD at 18 and 24 months, using autism-specific formal screening tests. [35] In contrast, in the UK, children whose families or doctors recognize possible signs of autism are screened. It is not known which approach is more effective. [36] [ clarification needed ] The UK National Screening Committee does not recommend universal ASD screening in young children. Their main concerns includes higher chances of misdiagnosis at younger ages and lack of evidence of effectiveness of early interventions. [37] There is no consensus between professional and expert bodies in the US on screening for autism in children younger than 3 years. [39]

Screening tools include the Modified Checklist for Autism in Toddlers (M-CHAT), the Early Screening of Autistic Traits Questionnaire, and the First Year Inventory; initial data on M-CHAT and its predecessor, the Checklist for Autism in Toddlers (CHAT), on children aged 18–30 months suggests that it is best used in a clinical setting and that it has low sensitivity (many false-negatives) but good specificity (few false-positives). [18] It may be more accurate to precede these tests with a broadband screener that does not distinguish ASD from other developmental disorders. [40] Screening tools designed for one culture's norms for behaviors like eye contact may be inappropriate for a different culture. [41] Although genetic screening for autism is generally still impractical, it can be considered in some cases, such as children with neurological symptoms and dysmorphic features. [42]

Diagnosis and assessment

Diagnosis of Autism Spectrum Disorder (ASD) relies on behavioral assessment, as no biological or genetic marker can yet confirm the condition. Diagnostic tools are designed to standardize clinical observations and parent reports to ensure accuracy and consistency across evaluators. Most tools are used in conjunction with professional clinical judgment and multidisciplinary evaluation. [43] [44] [45] [46] [47] [48]

Core diagnostic assessments

Autism Diagnostic Observation Schedule (ADOS, ADOS-2)

The Autism Diagnostic Observation Schedule (ADOS), first developed by Catherine Lord and colleagues in 1989 and revised as ADOS-2 in 2012, is a semi-structured, play-based assessment that observes social communication and restricted behaviors. [49] [50]

  • Structure: The ADOS-2 consists of five modules selected according to an individual's age and expressive language level.
  • Administration: Conducted by a trained clinician in 30–60-minute sessions.
  • Purpose: Measures spontaneous communication, social reciprocity, and use of imagination during structured activities.
  • Scoring: Each behavior is coded and algorithm scores are compared to threshold values indicating the likelihood of ASD.

The ADOS-2 is considered a "gold-standard" observational measure and is used worldwide in both clinical and research contexts. [51]

Autism Diagnostic Interview–Revised (ADI-R)

The Autism Diagnostic Interview–Revised (ADI-R) is a structured caregiver interview providing a developmental history of social behavior, communication, and restricted interests. [52]

  • Format: Conducted with a parent or primary caregiver and lasting 90–150 minutes.
  • Domains: Early social development, communication milestones, play skills, and repetitive behaviors.
  • Purpose: Captures information on an individual's lifetime development to supplement direct observation.
  • Scoring: Responses are numerically coded and analyzed against diagnostic algorithms corresponding to DSM-5 and ICD-11 criteria.

The ADI-R complements the ADOS-2 by documenting early development that may not be observable in a clinical setting.

Supplementary and Screening Measures

Although the ADOS-2 and ADI-R remain the primary diagnostic tools, several other instruments assist in screening or assessing related domains.

Developmental and Behavioral Screeners

  • Modified Checklist for Autism in Toddlers, Revised with Follow-Up (M-CHAT-R/F): A brief parent questionnaire for children aged 16–30 months, used for early detection of risk.
  • Social Communication Questionnaire (SCQ): Adapted from the ADI-R for children aged four years and older to screen for social communication difficulties.
  • Social Responsiveness Scale (SRS): A quantitative rating scale measuring severity of autism-related social impairment.

These screeners identify children who may benefit from a comprehensive diagnostic evaluation.

Cognitive and Adaptive Functioning Assessments

To contextualize ASD-specific findings, clinicians often include standardized assessments such as:

  • Wechsler Intelligence Scales or other cognitive tests to evaluate intellectual ability.
  • Vineland Adaptive Behavior Scales to assess daily living skills and social functioning.

These tools help distinguish autism from intellectual disability and guide individualized intervention planning. [53]

Integration and Clinical Judgment

Clinical accuracy depends on integrating standardized instruments with professional expertise. Diagnosing clinicians synthesize behavioral observations, developmental history, and test results to determine whether the individual meets criteria for ASD. Research emphasizes the importance of ongoing professional training and multidisciplinary collaboration to ensure consistent application of diagnostic tools. [53]

Emerging Tools and Technologies

Recent developments aim to improve access and reduce diagnostic delays: [43]

These innovations expand diagnostic accessibility while maintaining reliability standards.

Prevalence of autism diagnosis rates

From 2011 to 2022, there was a 175% increase in autism diagnosis rates. [58] According to the CDC, in 2023, 1 in 36 8-year olds were found to be diagnosed with ASD while in 2018, only 1 in 44 8-year olds were found to be diagnosed with ASD. [59] Studies also show that boys are more likely to be diagnosed with ASD than girls despite there being no difference between the two in symptoms and overall expression. [60]

See also

References

  1. Bjorklund et al. 2018.
  2. 1 2 American Psychiatric Association 2022.
  3. World Health Organization 2018.
  4. Baird G, Cass H, Slonims V (August 2003). "Diagnosis of autism". BMJ. 327 (7413): 488–493. doi:10.1136/bmj.327.7413.488. PMC   188387 . PMID   12946972.
  5. Lord, Catherine; Charman, Tony; Havdahl, Alexandra; Carbone, Paul; Anagnostou, Evdokia; Boyd, Brian; Carr, Themba; de Vries, Petrus J; Dissanayake, Cheryl; Divan, Gauri; Freitag, Christine M; Gotelli, Marina M; Kasari, Connie; Knapp, Martin; Mundy, Peter (2022). "The Lancet Commission on the future of care and clinical research in autism". The Lancet . 399 (10321): 271–334. doi:10.1016/S0140-6736(21)01541-5. hdl: 11250/2975811 . PMID   34883054. S2CID   244917920.
  6. "Section 2: Neurodevelopmental Disorders". Diagnostic and statistical manual of mental disorders: DSM-5-TR (Print) (Fifth edition, text revision. ed.). Washington, DC: American Psychiatric Association Publishing. 2022. ISBN   978-0-89042-575-6.
  7. Bjorklund, G. et al. (2018). "Diagnostic and Severity-Tracking Biomarkers for Autism Spectrum Disorder." Journal of Molecular Neuroscience, 66(4), 492–511.
  8. American Psychiatric Association. (2022). Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, Text Revision (DSM-5-TR). American Psychiatric Publishing.
  9. World Health Organization. (2018). International Classification of Diseases, 11th Revision (ICD-11). World Health Organization.
  10. 1 2 CDC (31 March 2022). "Screening and Diagnosis | Autism Spectrum Disorder (ASD) | NCBDDD". Centers for Disease Control and Prevention. Retrieved 12 September 2022.
  11. 1 2 Volkmar F, Cook EH, Pomeroy J, Realmuto G, Tanguay P (December 1999). "Practice parameters for the assessment and treatment of children, adolescents, and adults with autism and other pervasive developmental disorders. American Academy of Child and Adolescent Psychiatry Working Group on Quality Issues". Journal of the American Academy of Child and Adolescent Psychiatry. 38 (12 Suppl): 32S –54S. doi:10.1016/s0890-8567(99)80003-3. PMID   10624084.
  12. 1 2
  13. 1 2 3 Dover CJ, Le Couteur A (June 2007). "How to diagnose autism". Archives of Disease in Childhood. 92 (6): 540–545. doi:10.1136/adc.2005.086280. PMC   2066173 . PMID   17515625.
  14. Mantovani, John F (2000). "Autistic regression and Landau-Kleffner syndrome: progress or confusion?". Developmental Medicine and Child Neurology . 42 (5): 349–353. doi: 10.1111/j.1469-8749.2000.tb00104.x . PMID   10855658.
  15. Constantino JN, Charman T (March 2016). "Diagnosis of autism spectrum disorder: reconciling the syndrome, its diverse origins, and variation in expression" (PDF). The Lancet. Neurology. 15 (3): 279–91. doi:10.1016/s1474-4422(15)00151-9. PMID   26497771. S2CID   206162618.
  16. Matson JL, Neal D (2009). "Cormorbidity: diagnosing comorbid psychiatric conditions". Psychiatric Times. 26 (4). Archived from the original on 3 April 2013.
  17. Simms MD (February 2017). "When Autistic Behavior Suggests a Disease Other than Classic Autism". Pediatric Clinics of North America. 64 (1): 127–138. doi:10.1016/j.pcl.2016.08.009. PMID   27894440.
  18. 1 2 3 Landa RJ (March 2008). "Diagnosis of autism spectrum disorders in the first 3 years of life". Nature Clinical Practice. Neurology. 4 (3): 138–147. doi: 10.1038/ncpneuro0731 . PMID   18253102.
  19. Mandell DS, Novak MM, Zubritsky CD (December 2005). "Factors associated with age of diagnosis among children with autism spectrum disorders". Pediatrics. 116 (6): 1480–1486. doi:10.1542/peds.2005-0185. PMC   2861294 . PMID   16322174.
  20. Shattuck PT, Grosse SD (2007). "Issues related to the diagnosis and treatment of autism spectrum disorders". Developmental Disabilities Research Reviews. 13 (2): 129–135. doi:10.1002/mrdd.20143. PMID   17563895.
  21. Kanne SM, Randolph JK, Farmer JE (December 2008). "Diagnostic and assessment findings: a bridge to academic planning for children with autism spectrum disorders". Neuropsychology Review. 18 (4): 367–384. doi:10.1007/s11065-008-9072-z. PMID   18855144. S2CID   21108225.
  22. 1 2 3 Caronna EB, Milunsky JM, Tager-Flusberg H (June 2008). "Autism spectrum disorders: clinical and research frontiers". Archives of Disease in Childhood. 93 (6): 518–523. doi:10.1136/adc.2006.115337. PMID   18305076. S2CID   18761374.
  23. Schaefer GB, Mendelsohn NJ (January 2008). "Genetics evaluation for the etiologic diagnosis of autism spectrum disorders". Genetics in Medicine. 10 (1): 4–12. doi: 10.1097/GIM.0b013e31815efdd7 . PMID   18197051. S2CID   4468548.
  24. Huang Y, Arnold SR, Foley KR, Trollor JN (August 2020). "Diagnosis of autism in adulthood: A scoping review". Autism. 24 (6): 1311–1327. doi:10.1177/1362361320903128. hdl: 1959.4/unsworks_67142 . PMID   32106698. S2CID   211556350.
  25. "6A02 Autism spectrum disorder". ICD-11 for Mortality and Morbidity Statistics. Retrieved 2023-05-05. Some individuals with Autism Spectrum Disorder are capable of functioning adequately by making an exceptional effort to compensate for their symptoms during childhood, adolescence or adulthood. Such sustained effort, which may be more typical of affected females, can have a deleterious impact on mental health and well-being.
  26. 1 2 Lai MC, Szatmari P (March 2020). "Sex and gender impacts on the behavioural presentation and recognition of autism". Current Opinion in Psychiatry. 33 (2): 117–123. doi:10.1097/YCO.0000000000000575. PMID   31815760. S2CID   209164138.
  27. 1 2 3 Lockwood Estrin G, Milner V, Spain D, Happé F, Colvert E (29 October 2020). "Barriers to Autism Spectrum Disorder Diagnosis for Young Women and Girls: a Systematic Review". Review Journal of Autism and Developmental Disorders. 8 (4). Springer Science and Business Media LLC: 454–470. doi:10.1007/s40489-020-00225-8. PMC   8604819 . PMID   34868805.
  28. 1 2 Hull L, Petrides KV, Allison C, Smith P, Baron-Cohen S, Lai MC, Mandy W (August 2017). ""Putting on My Best Normal": Social Camouflaging in Adults with Autism Spectrum Conditions". Journal of Autism and Developmental Disorders. 47 (8): 2519–2534. doi:10.1007/s10803-017-3166-5. PMC   5509825 . PMID   28527095.
  29. 1 2 3 Filipek PA, Accardo PJ, Ashwal S, Baranek GT, Cook EH, Dawson G, et al. (August 2000). "Practice parameter: screening and diagnosis of autism: report of the Quality Standards Subcommittee of the American Academy of Neurology and the Child Neurology Society". Neurology. 55 (4): 468–79. doi: 10.1212/wnl.55.4.468 . PMID   10953176.
  30. 1 2 Ozonoff S, Goodlin-Jones BL, Solomon M (September 2005). "Evidence-based assessment of autism spectrum disorders in children and adolescents" (PDF). Journal of Clinical Child and Adolescent Psychology. 34 (3). Taylor & Francis: 523–40. doi:10.1207/s15374424jccp3403_8. ISSN   1537-4416. PMID   16083393. S2CID   14322690. Archived from the original (PDF) on 18 April 2021. Retrieved 3 September 2019.
  31. Corsello C, Hus V, Pickles A, Risi S, Cook EH, Leventhal BL, Lord C (September 2007). "Between a ROC and a hard place: decision making and making decisions about using the SCQ". Journal of Child Psychology and Psychiatry, and Allied Disciplines. 48 (9): 932–40. doi:10.1111/j.1469-7610.2007.01762.x. eISSN   1469-7610. hdl: 2027.42/74877 . ISSN   0021-9630. OCLC   01307942. PMID   17714378.
  32. Huerta M, Lord C (February 2012). "Diagnostic evaluation of autism spectrum disorders". Pediatric Clinics of North America. 59 (1): 103–11, xi. doi:10.1016/j.pcl.2011.10.018. PMC   3269006 . PMID   22284796.
  33. Kan CC, Buitelaar JK, van der Gaag RJ (June 2008). "Autismespectrumstoornissen bij volwassenen" [Autism spectrum disorders in adults]. Nederlands Tijdschrift voor Geneeskunde (in Dutch). 152 (24): 1365–1369. PMID   18664213.
  34. "Autism case training part 1: A closer look – key developmental milestones". CDC.gov. 18 August 2016. Retrieved 5 August 2019.
  35. Kamio, Yoko; Haraguchi, Hideyuki; Stickley, Andrew; Ogino, Kazuo; Ishitobi, Makoto; Takahashi, Hidetoshi (December 2015). "Brief Report: Best Discriminators for Identifying Children with Autism Spectrum Disorder at an 18-Month Health Check-Up in Japan". Journal of Autism and Developmental Disorders. 45 (12): 4147–4153. doi:10.1007/s10803-015-2527-1. ISSN   0162-3257. PMC   4653231 .
  36. Levy SE, Mandell DS, Schultz RT (November 2009). "Autism". Lancet. 374 (9701): 1627–1638. doi:10.1016/S0140-6736(09)61376-3. PMC   2863325 . PMID   19819542. (Erratum:  doi:10.1016/S0140-6736(11)61666-8,  )
  37. 1 2 3 4 5 6 Siu AL, Bibbins-Domingo K, Grossman DC, Baumann LC, Davidson KW, Ebell M, et al. (February 2016). "Screening for Autism Spectrum Disorder in Young Children: US Preventive Services Task Force Recommendation Statement". JAMA. 315 (7): 691–696. doi: 10.1001/jama.2016.0018 . PMID   26881372.
  38. Johnson CP, Myers SM (November 2007). "Identification and evaluation of children with autism spectrum disorders". Pediatrics. 120 (5). American Academy of Pediatrics: 1183–1215. doi:10.1542/peds.2007-2361. PMID   17967920. S2CID   218028., cited in Blumberg SJ, Zablotsky B, Avila RM, Colpe LJ, Pringle BA, Kogan MD (October 2016). "Diagnosis lost: Differences between children who had and who currently have an autism spectrum disorder diagnosis". Autism. 20 (7): 783–795. doi:10.1177/1362361315607724. PMC   4838550 . PMID   26489772.
  39. For example:
    • US Preventive Services Task Force does not recommend universal screen of young children for autism due to poor evidence of benefits of this screening when parents and clinicians have no concerns about ASD. The major concern is a false-positive diagnosis that would burden a family with very time-consuming and financially demanding treatment interventions when it is not truly required. The Task Force also did not find any robust studies showing effectiveness of behavioral therapies in reducing ASD symptom severity. [37]
    • American Academy of Pediatrics recommends ASD screening of all children between the ages if 18 and 24 months. [37] The AAP also recommends that children who screen positive for ASD be referred to treatment services without waiting for a comprehensive diagnostic workup [38]
    • The American Academy of Family Physicians did not find sufficient evidence of benefit of universal early screening for ASD [37]
    • The American Academy of Neurology and Child Neurology Society recommends general routine screening for delayed or abnormal development in children followed by screening for ASD only if indicated by the general developmental screening [37]
    • The American Academy of Child and Adolescent Psychiatry recommend routinely screening autism symptoms in young children [37]
  40. Wetherby AM, Brosnan-Maddox S, Peace V, Newton L (September 2008). "Validation of the Infant-Toddler Checklist as a broadband screener for autism spectrum disorders from 9 to 24 months of age". Autism. 12 (5): 487–511. doi:10.1177/1362361308094501. PMC   2663025 . PMID   18805944.
  41. Wallis KE, Pinto-Martin J (May 2008). "The challenge of screening for autism spectrum disorder in a culturally diverse society". Acta Paediatrica. 97 (5): 539–540. doi:10.1111/j.1651-2227.2008.00720.x. PMID   18373717. S2CID   39744269.
  42. Lintas C, Persico AM (January 2009). "Autistic phenotypes and genetic testing: state-of-the-art for the clinical geneticist". Journal of Medical Genetics. 46 (1): 1–8. doi:10.1136/jmg.2008.060871. PMC   2603481 . PMID   18728070.
  43. 1 2 3 4 Howes, A. E.; Burns, M. E.; & Surtees, A. D. R. (2021). Barriers, Facilitators, and Experiences of the Autism Assessment Process: A Systematic Review of Qualitative Research with Health Professionals. Professional Psychology: Research and Practice.
  44. Lord, C.; Rutter, M.; DiLavore, P.; Risi, S.; Gotham, K.; & Bishop, S. (2012). Autism Diagnostic Observation Schedule, Second Edition (ADOS-2). Western Psychological Services.
  45. Lord, C.; Rutter, M.; Goode, S.; Heemsbergen, J.; Jordan, H.; Mawhood, L.; & Schopler, E. (1989). "Autism Diagnostic Observation Schedule: A Standardized Observation of Communicative and Social Behavior." Journal of Autism and Developmental Disorders, 19(2), 185–212.
  46. Rutter, M.; Le Couteur, A.; & Lord, C. (2003). Autism Diagnostic Interview–Revised (ADI-R). Western Psychological Services.
  47. Kamp-Becker, I. et al. (2018). "Diagnostic Accuracy of the ADOS and ADOS-2 in Clinical Practice." European Child & Adolescent Psychiatry, 27(9), 1193–1207.
  48. American Psychiatric Association. (2013). Diagnostic and Statistical Manual of Mental Disorders (5th ed.). American Psychiatric Publishing.
  49. Lord et al. 1989.
  50. Lord et al. 2012.
  51. Kamp-Becker et al. 2018.
  52. Rutter, Le Couteur & Lord 2003.
  53. 1 2 Howes, Burns & Surtees 2021.
  54. Juárez, A. P.; Weitlauf, A. S.; Nichols, H. M.; Broderick, N. A.; Hollway, J. A. (2022). "A Randomized Trial of the Remote Autism Diagnostic Observation Schedule (Tele-ADOS) for Toddlers During COVID-19". Journal of Autism and Developmental Disorders. 52 (9): 3980–3992. doi:10.1007/s10803-021-05190-4.
  55. Thabtah, Fadi (2022). "Machine Learning in Autism Spectrum Disorder Behavioral Research: A Review and Ways Forward". Informatics in Medicine Unlocked. 33 101096. doi:10.1016/j.imu.2022.101096.
  56. Zhao, Y.; Wu, J. (2023). "Deep Learning-Based Video Analysis for Automated Autism Screening in Young Children". JAMA Network Open. 6 (7): e2320492. doi:10.1001/jamanetworkopen.2023.20492.
  57. Norbury, Courtney F.; Sparks, Anna (2013). "Difference or Disorder? Cultural Issues in Understanding Neurodevelopmental Disorders". The Lancet Psychiatry. 1 (2): 91–100. doi:10.1016/S2215-0366(14)70283-9.
  58. Grosvenor, Luke P.; Croen, Lisa A.; Lynch, Frances L.; Marafino, Ben J.; Maye, Melissa; Penfold, Robert B.; Simon, Gregory E.; Ames, Jennifer L. (2024-10-30). "Autism Diagnosis Among US Children and Adults, 2011-2022". JAMA Network Open. 7 (10): e2442218. doi:10.1001/jamanetworkopen.2024.42218. ISSN   2574-3805. PMC   11525601 .
  59. "CDC Newsroom". CDC. 2016-01-01. Retrieved 2024-11-25.
  60. Duvekot, Jorieke; van der Ende, Jan; Verhulst, Frank C; Slappendel, Geerte; van Daalen, Emma; Maras, Athanasios; Greaves-Lord, Kirstin (August 2017). "Factors influencing the probability of a diagnosis of autism spectrum disorder in girls versus boys" . Autism. 21 (6): 646–658. doi:10.1177/1362361316672178. ISSN   1362-3613.