Summary
Developmental surveillance and standardized screening exist to identify autism spectrum disorder early, because earlier identification opens access to intervention during a period of maximal developmental plasticity [1][2]. Screening is a structured supplement to surveillance, not a replacement for the clinician's ongoing developmental judgment [1].
- Combine ongoing developmental surveillance at every visit with standardized autism-specific screening at the 18- and 24-month visits [1].
- The Modified Checklist for Autism in Toddlers, Revised with Follow-Up is the most widely used tool, and its two-stage design reduces false positives by adding a structured follow-up interview to a positive initial checklist [3].
- A positive screen is not a diagnosis. It triggers referral for comprehensive diagnostic evaluation and for early intervention services in parallel, without waiting for the diagnosis to be confirmed [1].
- General developmental screening at the 9-, 18-, and 30-month visits complements the autism-specific tools and captures the broader developmental delays that often accompany or mimic autism [1].
Caution. Do not let a negative screen override clinical or parental concern. Screening tools miss cases, and a child whose parent or clinician is worried warrants evaluation regardless of the score. Screening supplements surveillance; it does not veto it [1].
Screening
The recommended schedule layers general and autism-specific screening across the toddler visits [1].
| Visit |
Screening |
| 9 months |
General developmental screening [1] |
| 18 months |
General developmental plus autism-specific screening [1] |
| 24 months |
Autism-specific screening [1] |
| 30 months |
General developmental screening [1] |
The two-stage autism screen is the core instrument. The initial checklist identifies children at risk, and the structured follow-up interview on the intermediate-risk group sharpens the result before referral.
Score the checklist and follow-up in M-CHAT-R/F →
A broad psychosocial screen helps capture the developmental and behavioral concerns that present alongside autism in the same visits.
Screen for psychosocial concerns in PSC-17 →
Attention and hyperactivity symptoms frequently co-occur with autism and become more prominent at school age, so structured rating scales are useful when those concerns emerge.
Collect structured ADHD rating-scale data in Vanderbilt ADHD →
Evaluation
A positive screen sets two referrals in motion at once. The first is a comprehensive diagnostic evaluation by a clinician or team experienced in autism, which integrates developmental history, direct observation, and a standardized diagnostic instrument [1][4]. The second is immediate referral to early intervention, because eligibility for services does not require a confirmed diagnosis and the intervention window is time-sensitive [1].
The diagnostic evaluation also looks for co-occurring and contributing conditions, including intellectual disability, language disorder, hearing impairment, and specific genetic conditions, since these change management and counseling [2][4]. Autism is clinically heterogeneous, and its presentation ranges from the child with obvious early language regression to the verbally fluent child whose social differences surface only under school-age demands [4].
Management is multidisciplinary and centered on evidence-based behavioral and developmental intervention, with medical treatment reserved for specific co-occurring symptoms rather than for the core condition [1][4]. The clinician's role continues after diagnosis, coordinating services, monitoring for co-occurring conditions, and supporting the family [1].
References
- Hyman SL, Levy SE, Myers SM, et al. Identification, evaluation, and management of children with autism spectrum disorder. Pediatrics. 2020;145(1):e20193447. doi:10.1542/peds.2019-3447
- Hyman SL, Levy SE, Myers SM. Executive summary: identification, evaluation, and management of children with autism spectrum disorder. Pediatrics. 2020;145(1):e20193448. doi:10.1542/peds.2019-3448
- Robins DL, Casagrande K, Barton M, 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. doi:10.1542/peds.2013-1813
- Lord C, Elsabbagh M, Baird G, Veenstra-Vanderweele J. Autism spectrum disorder. Lancet. 2018;392(10146):508-520. doi:10.1016/S0140-6736(18)31129-2