Frequently Asked Questions

How does NCSA define severe autism?

NCSA believes in many “autisms.” A 2025 study by Whiteley and colleages examined the pluralisation of autism based on different severity levels and different developmental trajectories (Whiteley et al., British Journal of Psychiatry, 2025). As with many issues in autism, there is no single scientifically precise definition of "severe autism" adopted uniformly across clinical, research, or policy contexts. NCSA recognizes many severe forms of autism and, thus, uses the term “severe autism” as an encompassing term for those many forms. “Severe autism” describes individuals who meet the DSM-5 criteria for Autism Spectrum Disorder (ASD), who have significant functional impairment, intellectual disability (IQ ≤70), and who depend on caregivers for safety, supervision, and support at a constant to near-constant level consistently throughout their entire lives. This typically includes individuals who have no to negligible functional communication and who may engage in dangerous behaviors such as aggression, self-injury, elopement, or pica. This is not a description of the full autism spectrum. It describes the most significantly affected subgroup whose safety and well-being are gravely impacted without appropriate, specialized care — one that is frequently excluded from mainstream autism advocacy, policy discussions, and research priorities.

What is the difference between "severe autism" and "profound autism"?

Both terms describe the most significantly affected individuals with autism, and NCSA uses both."Severe autism" is the broader, more established informal term. "Profound autism" is a more recent academic designation developed to better capture the subpopulation most excluded in clinical research. A 2023 study by Hughes and colleagues estimated that approximately 26.7% of 8-year-old children with autism met the “profound autism” threshold first introduced by the Lancet Commission in 2021 (Hughes et al., CDC/MMWR, 2023; Lord et al., The Lancet, 2021). The original criteria, however, were not defined by factors NCSA had long held as contributing to the greatest support needs (i.e., self-injury/aggression, IQ ≤70 not 50, etc). A new consensus for a more precise classification of the term “profound autism” was announced during the 2025 annual meeting of the International Society for Autism Research (INSAR). See here for details on the new criteria for “profound autism,” which now more closely align with the broader community NCSA has been serving since 2018. NCSA uses both terms, recognizing that "profound autism" carries emerging clinical specificity while "severe autism" remains widely understood by families and policymakers alike.

How many Americans are affected by severe forms of autism?

According to the CDC's Autism and Developmental Disabilities Monitoring (ADDM) Network, approximately 1 in 31 (3.22%) of 8-year-old children were identified with autism spectrum disorder in 2022 — the most recent surveillance year available (Shaw, CDC Surveillance Summaries, 2025). Of those with data on cognitive ability, 39.6% had autism with co-occurring intellectual disability (IQ ≤70) (Shaw, CDC Surveillance Summaries, 2025). While autism diagnoses have risen steeply over recent decades, rates of intellectual disability have remained comparatively flat, suggesting that expanded diagnostic criteria and increased awareness do not fully account for the rise (Van Naarden Braun et al., 2015). Data from California's Department of Developmental Services show an exponential rise in individuals served, approaching nearly 20,000 by birth year 2019 (California DDS records request, Lauren Libero, January 2026). These numbers represent hundreds of thousands of Americans with profound support needs, and millions of family members and caregivers bearing the weight of a system that has failed to keep pace.

What causes autism?

Autism is a complex neurodevelopmental condition with multiple contributing causes, including genetic, genomic, and environmental factors. Research has identified hundreds of genetic variants associated with autism risk, and in some individuals a single causative mutation can be identified — such as in SYNGAP1, FMR1 (Fragile X), or TSC1/TSC2 (tuberous sclerosis). In many cases, no single cause is identified, reflecting what researchers call the "missing heritability" of autism (Thapar and Rutter, J Autism Dev Disord, 2021). The science of autism causation is active and evolving, and NCSA supports rigorous inquiry into all plausible contributing factors.

The causal relationship between childhood vaccines and autism has been studied extensively across large populations worldwide; peer-reviewed research to date has not established a causal link between vaccination and autism. NCSA's positions follow the scientific evidence as the research community develops it, and we recognize that the science continues to evolve. NCSA supports vaccination in accordance with the recommendations of the American Academy of Pediatrics. We also recognize that many families in our community have deeply personal beliefs about the origins of their child's condition. Families need not agree with every NCSA position to find a home here.

What does NCSA mean by "related disorders"?

NCSA's mission encompasses individuals severely affected by autism and related disorders. These are conditions that share functional features with severe autism — significant intellectual disability, behavioral challenges, communication impairment, and dependence on lifelong supports — and that often co-occur with autism or are classified under the autism spectrum. Examples include, but are not limited to, genetic conditions such as Fragile X Syndrome (FMR1), Phelan-McDermid Syndrome (SHANK3), SynGAP1-Related Disorders (SynGAP1), Angelman Syndrome (UBE3A), and Rett Syndrome (MECP2). In some cases, individuals with these diagnoses have also received an autism diagnosis; in others, the related disorder is the primary diagnosis, but the functional profile and support needs are comparable to those of individuals with severe forms of autism.

Does NCSA contend that autistic people with lower support needs are not disabled?

No. Every form of autism is real, and every autistic person's experience and challenges matter. Many autistic people with lower support needs experience severe disabilities — including significant mental health conditions, employment difficulties, sensory processing challenges, and profound social isolation. NCSA does not dispute that. Our focus on severe autism is not a claim that other autistic people are not disabled or that their needs are unimportant. It is a recognition that the individuals we represent have been systematically underserved and underrepresented in policy, research, and advocacy, and that their particular needs require dedicated attention they have not received.

Is NCSA duplicating the work of other autism advocacy organizations?

No. The mainstream autism advocacy landscape has shifted substantially over the past two decades toward centering the priorities of autistic people with higher cognitive abilities and functional communication abilities. While this shift has produced important advances for some portions of the autism community, it has simultaneously left individuals with severe and profound autism — those who cannot self-advocate effectively, who have limited to no functional communication, and who depend entirely on caregivers and a functional support system — without adequate representation in federal policy, research funding priorities, or public discourse. NCSA was founded in 2018 to fill that gap. Our work is not duplicative; it is corrective.

What is Applied Behavior Analysis (ABA) and why does NCSA support access to it?

Applied Behavior Analysis (ABA) is a therapeutic approach grounded in the science of learning and behavior. When appropriately designed and implemented, ABA can help individuals with severe autism reduce dangerous behaviors — including aggression, self-injury, elopement, and pica — and build adaptive skills that support greater independence and quality of life. NCSA supports broad access to recognized evidence-based interventions across the lifespan for individuals with severe and profound autism and opposes efforts to deny or restrict that access on ideological grounds. ABA, like any clinical approach, varies in quality and implementation; NCSA supports individualized, evidence-based, and compassionate application through contemporary practices — not aversive techniques such as contingent shock. See our full position statement on ABA to learn more.

What is the neurodiversity movement and how does NCSA relate to it?

The neurodiversity movement holds that neurological differences — including autism — are natural human variation rather than deficits requiring correction or cure. NCSA respects that framework as it applies to many autistic individuals, and we share the movement's commitment to dignity, inclusion, and self-determination. However, the movement's dominant policy positions frequently do not account for those with severe and profound autism, who face life-threatening behavioral challenges, require full-time supervision, and in many cases cannot communicate their own preferences at all. NCSA does not oppose neurodiversity as a concept. We oppose its misapplication as a universal policy framework — one that, in practice, excludes those most in need of protection.

Does NCSA support research into autism causes?

Yes, unequivocally. NCSA supports rigorous scientific research into all aspects of autism — prevalence, causation, biology, treatment, and outcomes — with particular urgency around the needs of those most severely affected. We reject the framing that researching the causes of autism is inherently eugenically motivated. Understanding causation is essential to developing effective interventions, identifying at-risk populations, and informing sound public health and education policy. The dramatic, documented rise in autism prevalence warrants serious scientific inquiry, and NCSA insists on that inquiry being conducted with methodological rigor and scientific integrity, free from ideological constraint.

What residential and community supports does NCSA advocate for?

NCSA advocates for a full continuum of residential, therapeutic, and community support options for individuals with severe and profound autism — including group homes, supported living arrangements, specialized therapeutic settings, and family-based models supported by robust home and community-based services (HCBS). We oppose policies that artificially restrict housing to a single model. The current shortage of qualified direct support professionals and appropriate residential placements constitutes a crisis affecting hundreds of thousands of American families, and NCSA presses for legislative and regulatory solutions at both the state and federal level.

Why does NCSA focus on a specific subgroup rather than all autism?

Because all parts of the autism spectrum are not equally represented in policy, research, or advocacy, and the representation gap is most severe for those with the most severe forms of autism. Individuals with profound and severe autism who have negligible functional communication, who have intellectual disability, and who require around-the-clock support face fundamentally different challenges and policy needs than those with normal to above average IQ, who require supports intermittently or at a minimal to moderate level, and who are capable of effective self-advocacy. Treating the autism spectrum as a monolith routinely obscures these differences and consistently disadvantages those who cannot effectively speak for themselves. NCSA exists to ensure that this population is counted, heard, and served.

How does NCSA work with families and caregivers?

Families and caregivers are the backbone of the severe autism community and the primary constituency NCSA is accountable to. We work to amplify family voices in federal and state policy processes, provide resources and information grounded in rigorous science, and build a national community through the NCSA National Grassroots Network. Family caregivers are often the most reliable proxy to express the authentic needs of their loved one. Their knowledge, their grief, and their insistence on better must be centered — not managed, not patronized, not dismissed, and not explained away. Attempts to silence families caring for those with severe autism effectively silence the individual with severe autism who does not have the functional communication or cognitive capacity to engage in policy debates that decide their supports and services.

How can I submit content or connect with NCSA?

NCSA welcomes blog submissions, personal stories, and policy perspectives from families and caregivers affected by severe autism. Submissions may be sent to info@ncsautism.org. For policy questions, contact policy@ncsautism.org. For media inquiries, contact press@ncsautism.net. You can also follow NCSA on social media and join the National Grassroots Network to stay informed and connected with families across the country.

How can I support NCSA?

The most meaningful way to support this work is through a tax-deductible donation. NCSA is a 501(c)(3) nonprofit organization entirely dependent on the generosity of individuals and families who believe that those most severely affected by autism deserve a voice in the rooms where decisions are made. Every donation — at any level — directly funds advocacy, policy work, public education, and the infrastructure that lets family voices reach federal and state decision-makers. Donations can be made at NCSAutism.org/donate.

You can also make an impact on the ground by joining the NCSA National Grassroots Network — a growing community of families, providers, and advocates working to advance policy change at the state and federal level. Membership is free. The work is urgent.

These FAQs are subject to revision by the NCSA Board of Directors at any time.

NCSA is a community that welcomes all families and caregivers affected by severe autism. Families need not agree with every NCSA position to find a home here. Our common purpose is ensuring that those most severely affected by severe forms of autism have the policy, recognition, and solutions they deserve.