What autism is
- Read the behaviour as a message. Check pain, noise, hunger and change before you correct anything. Behaviour is communication.
- Ask which support level the report gives, then stop treating it as a ceiling. It describes today. The three levels.
- If the child is under 3, call your state's early intervention programme today. The evaluation is free by law, no referral needed. Across a lifetime.
- Get the medical list checked, not just the behaviour list. Seizures, gut pain and sleep show up as behaviour first. What comes with it.
- Stop looking for what you did wrong. The evidence points at genes. No parenting style causes autism. What causes it.
What autism is
The CDC: autism spectrum disorder is a developmental disability caused by differences in the brain. It "begins before the age of 3 years and can last throughout a person's life, although symptoms may change over time."
Clinicians diagnose it on two areas only, from their manual, the DSM-5-TR:
- Social communication and interaction. Lasting differences in back-and-forth conversation, body language, and building relationships. CDC's examples: avoiding eye contact, not responding to a name by 9 months, not pointing to show you something by 18 months.
- Restricted and repetitive patterns. At least two of: repeated movements or speech (lining things up, echoing phrases, hand flapping, rocking), needing sameness, intense focused interests, and sensory differences, meaning over- or under-reactivity to sensory input. A hand dryer that makes a shop unbearable is part of the diagnosis.
The signs must be present in early childhood, though the manual says they may be "masked by learned strategies in later life." That is why someone diagnosed at 40 was autistic at 4. Autism is not an illness, and there is no cure to hunt for: a different brain is not a broken one.
How common it is
The CDC's ADDM Network published its latest count in April 2025, from 2022 data at 16 US sites. About 1 in 31 children aged 8 (3.2%) was identified as autistic. Autism was 3.4 times as common in boys (49.2 per 1,000) as in girls (14.3 per 1,000).
In 2000 it was 1 in 150. Sites in the same country range from 1 in 103 in Laredo, Texas to 1 in 19 in California. CDC's explanation: "differences in ASD prevalence are likely due to differences in evaluation and testing practices." Research, it adds, "does not show that living in certain communities puts children at greater risk for developing ASD."
So the count largely tracks who gets looked at. The definition broadened when separate diagnoses were folded into one spectrum, recognition came earlier, and more children are evaluated at all. Your child is not part of an epidemic, but of a group that used to be missed.
The varying degrees of need
The DSM-5-TR records how much support a person needs, in three levels:
- Level 1, "requiring support." Without supports, the social differences "cause noticeable impairments." In life: a teenager who talks happily about trains, cannot start a conversation with a classmate, and falls apart after a day of holding it together.
- Level 2, "requiring substantial support." Marked differences that stay obvious even with supports. In life: a child who speaks in short phrases, needs the same route home, and needs an hour of help after a changed plan.
- Level 3, "requiring very substantial support." Very little social initiation, and behaviours that "markedly interfere with functioning in all spheres." In life: an adult who communicates with a device or a few signs, and needs someone within reach all day.
Hold the level lightly. It is a snapshot of one day, not a verdict, and it moves with the year, the school, the sleep and the noise. Written for services and funding, it tells you what to build, not what to expect.
It is also two numbers, not one. The manual says severity "should be separately rated" for social communication and for restricted, repetitive behaviours. The same person can be Level 1 in one and Level 3 in the other. If your report gives a single number, ask for both.
We do not say "high-functioning" or "low-functioning": they hide a Level 1 person's real struggles and lower what is expected of a Level 3 person. In the UK survey described below, only a minority of autistic adults endorsed either term.
The words "profound autism"
In 2021 the Lancet Commission on the future of care and clinical research in autism proposed the term profound autism. It is for people who are "minimally verbal or non-verbal, are not able to advocate for themselves, and require 24-hour access to an adult who can care for them." Across six research samples, 11% to 48% of autistic people met it (Clarke and others, 2024). The aim was to make clinicians and researchers prioritise a group it called vulnerable and underserved.
CDC researchers then measured it across 15 ADDM sites, counting 8-year-olds who were nonverbal, minimally verbal, or had an IQ under 50. 26.7% of autistic 8-year-olds met that definition. In 2016 it affected 4.6 per 1,000 8-year-olds, and those children were more likely to have seizure disorders and self-injurious behaviour.
Autistic self-advocates object, specifically. The Autistic Self Advocacy Network says the definition "conflates needing 24/7 support with having a measured IQ of 50 or below or being nonspeaking," which it calls "a harmful oversimplification." Some people who speak fluently need round-the-clock support; some device users live independently. ASAN adds that "IQ tests are notoriously unreliable for autistic people, particularly nonspeaking autistics."
Both are worth hearing. If the term gets your family a placement, use it. If a clinician uses it as a reason to stop teaching your child to read, do not accept it.
Across a lifetime
The toddler years
Some signs show in the first 12 months. In others, CDC says, they "may not show up until 24 months of age or later." What families notice: no response to their own name, no pointing to share something, losing words they used to have, an extreme reaction to a sound or a texture.
You do not need a diagnosis, a referral, or money to start. Under IDEA Part C, every state runs early intervention from birth to the third birthday. The Center for Parent Information and Resources states the evaluation "is free of charge," and that Child Find, evaluations, the IFSP and service coordination cost families nothing. Other services may carry a sliding-scale fee by state.
Call the programme yourself, and put it in writing, so there is a date. I am worried about my child's development. I would like to request an evaluation for early intervention services. More on the school page.
School age
Some children hold together all day by sheer effort, then release everything at home. Others cannot hold it together at school, and the calls start. Now the environment becomes negotiable: noise, lighting, transitions, unstructured lunchtimes and handwriting demands can all be written into a plan. See the school page.
The teen years
Puberty arrives on the usual schedule, with a widening social gap that autistic teenagers usually notice themselves. Watch mental health. A 2019 meta-analysis in The Lancet Psychiatry found pooled rates of 20% for anxiety disorders and 11% for depressive disorders in the autism population.
Masking is the hidden cost. The National Autistic Society calls it "a strategy used by some autistic people, consciously or unconsciously, to appear non-autistic in order to fit in and be accepted in society." It looks like forcing eye contact, mirroring expressions, suppressing stimming, scripting conversations in advance. NAS says the effects include exhaustion and autistic burnout, and increased suicidality or self-harm.
Masking is why girls get missed. NAS notes that autistic women, girls and non-binary people may mask more than autistic men and boys, and that it causes late diagnosis or none. If this is a 14-year-old girl called shy and anxious for a decade, you are not imagining it.
Adult life
School ends and the scaffolding goes with it. What the district arranged must now be assembled by you and by them: benefits, health cover, work, housing, and who gets to decide. See adult life.
Growing older
Nobody knows enough here yet. A 2025 review reported that less than 1% of autism research has focused on older autistic people, and cited an estimate that 89% of autistic people aged 40 to 59 may be undiagnosed. What research does find: higher rates of physical and mental health conditions, lower quality of life than non-autistic peers, and real benefit from social connection.
The other ageing person here may be you. If the question underneath is what happens when you are gone, that one has real answers: when I am gone.
What often comes with it
Autism rarely travels alone, and the companions are often treatable.
- Intellectual disability. 39.6% of autistic 8-year-olds with cognitive testing in CDC's 2022 data (IQ of 70 or below).
- Epilepsy. Children's Hospital of Philadelphia states 25% to 40% of autistic patients. CDC: about 1% of US adults.
- ADHD. Pooled prevalence of 28% in The Lancet Psychiatry meta-analysis.
- Anxiety. 20% in the same analysis, with obsessive-compulsive disorder at 9%.
- Gut problems. Estimates vary widely by study, from 9% to 70%, with chronic constipation at a median of 22%.
- Sleep. Chronic sleep problems in 50% to 80% of autistic children, against 9% to 50% of non-autistic children.
- Feeding differences. Around 27% have problems with food selectivity, often linked to the gut problems above.
Why the list matters. An autistic person in pain may not be able to tell you where. Constipation, reflux, an ear infection, a bad tooth or a seizure can arrive as screaming, hitting, refusing food or not sleeping.
Behaviour is communication
Behaviour is a message from someone who cannot deliver it another way. The job is to read it, not to stop it.
A meltdown is not a tantrum. The National Autistic Society defines it as "an intense response to an overwhelming situation" in which someone "temporarily loses control of their behaviour", and says directly: "A meltdown is not the same as a temper tantrum. It is not bad or naughty behaviour." A tantrum has an audience and a goal. A meltdown has neither, and giving the person what they wanted does not end it.
A shutdown is not defiance. The same overload can go inward: going still and silent, refusing to move, appearing to ignore you. Pushing harder makes it longer. NAS describes an earlier "rumble stage" of pacing, repeated questions, rocking or becoming still. That stage is your window.
Check these five before you correct anything:
- Pain or illness. Teeth, ears, gut, head, seizures.
- Sensory load. Noise, lights, smell, crowding, a label in a shirt, a hand dryer two rooms away.
- Change. A different route, a substitute teacher, a plan that shifted without warning.
- Fear. Something that happened here before, or something coming that nobody explained.
- An unmet need with no words attached. Hunger, thirst, the toilet, needing to leave.
NAS's first advice for the moment itself is to give time and make space. More on Help now.
The words, and why they matter
We say "autistic person" rather than "person with autism", because autistic adults asked for it. Kenny and colleagues' 2016 study in the journal Autism surveyed the UK autism community: more autistic adults endorsed "autistic" and "autistic person" than "person with autism". The same study found no single term everyone accepted.
- "Autistic" is a description, the way "left-handed" is. Lowering your voice to say it teaches a child that it is shameful.
- "Nonspeaking" beats "nonverbal". Many people who do not speak use language by typing, writing, signing or a device. "Nonverbal" gets heard as "understands nothing", and that leads to being talked over.
- Never "suffers from autism". A person may suffer from pain, from anxiety, or from a world built for someone else. That is a different sentence.
- Say "non-autistic", not "normal". The opposite of a normal child is a wounded one.
Loving families use both kinds of language, and some autistic adults prefer person-first. If the person can tell you what they want to be called, that outranks every survey.
What causes it, and what does not
The weight of the evidence sits on genetics. NICHD states that "a great deal of evidence supports the idea that genes are one of the main causes of or a major contributor to ASD," and that "more than 100 genes on different chromosomes may be involved." There is no single autism gene, which is why there is no simple test.
CDC says "scientists believe there are multiple causes of ASD that act together". What makes it more likely: an autistic sibling, genetic conditions such as fragile X syndrome or tuberous sclerosis, complications at birth, older parents. Other environmental factors are under study, not settled.
Vaccines do not cause autism. The American Academy of Pediatrics puts it in one sentence: "Decades of rigorous research have shown vaccines do not cause autism." On the 1998 study that started the claim, AAP says "the results of the study were later proven false". On the mercury preservative: "no causal association was found between ASD and thimerosal (mercury)."
Read on 5 September 2026, CDC's own "Autism and Vaccines" page, changed under the Data Quality Act, now says that claim "is not an evidence-based claim"; the research did not change, so we quote the AAP.
It is nobody's fault. Not how you held your baby, not screen time, not working, not divorce, not diet, not anything you have replayed at 3am. Cold parenting was blamed for decades, and that theory was wrong. Autism starts before birth, in the wiring.
ABA, medication, and telling your child the diagnosis: both sides, with the questions to ask, on hard choices.
"For You formed my inmost being; You knit me together in my mother's womb. I praise You, for I am fearfully and wonderfully made. Marvelous are Your works, and I know this very well." (Psalm 139:13-14, Berean Standard Bible.) Made, on purpose, and known. Not a project to be corrected back into someone else.
Verified September 2026 against the CDC's autism pages and the ADDM Network's 2025 report, the DSM-5-TR criteria, NICHD, the American Academy of Pediatrics, the Lancet Commission, the Autistic Self Advocacy Network and the National Autistic Society. Sources on the sources page. Background for a caregiver, not medical, legal or financial advice.