# Lost words and skills: regression is a red flag, not a phase

> Your toddler used to say words, wave or point, and has stopped. Why losing skills is a reason to act now, and where to start in Quebec.

- Reading time: 5 min
- Evidence level: strong
- Reviewed: 2026-09-03
- Canonical: https://neurosphere.club/resources/lost-words-regression

**Losing words or skills a child already had is on Canada's official list of autism signs and is common in autistic children, typically around 18 to 24 months. It is not a phase to wait out. Write down what was lost and when, and ask for a developmental referral and a hearing test this week.**


Your child had words. "Mama", "ball", "bye-bye", maybe ten of them. Or they used to wave and look at you when you came in the room. Then, over a few weeks or months, those things faded. Someone told you it is a phase. This page is here to say, calmly and directly: it is not, and you are right to be paying attention.

## What "regression" means

Regression is the loss of skills a child already had. In young children it usually shows up as:

- **Words disappearing.** A child who said several words and now says few or none.
- **Gestures fading.** Waving, pointing and reaching to be picked up stop.
- **Social engagement dimming.** Less eye contact, less turning to their name, less interest in peek-a-boo or in you.
- **Play narrowing.** Pretend play or copying stops; play becomes repetitive.

The Public Health Agency of Canada lists "starting to develop language skills but then stopping or losing those skills" among the signs of autism it asks parents and clinicians to watch for. [Evidence: official]

## Why it is a red flag and not a phase

Regression is common in autism, and it happens right in the window when most early signs appear. A large review that pooled 85 studies and more than 29,000 children found regression reported in roughly a third of autistic children, with an average onset around 21 months. Language regression alone was the most common pattern; language and social regression together was reported even more often when studies looked for both. [Evidence: strong]

Two things follow from that.

First, losing skills is different from developing slowly. A child who is simply late may be on their own timetable. A child who *had* a skill and lost it has changed direction. Clinicians treat that change as meaningful, and so should the person you talk to.

Second, the age is not a coincidence. Regression tends to appear around the same time as the other reliable signs (pointing, response to name, shared gaze), and around the age the M-CHAT-R/F is designed to be used. In Canada the median age of diagnosis is 3.7 years. A regression at 20 months, noticed and acted on, is a chance to close most of that gap. [Evidence: official]

## What regression does not mean

It is worth being precise, because the word frightens people.

- **It is not something you caused.** Vaccination, screens, a new sibling, a move: none of these cause autism. Autism is very largely inherited; a study of over two million children across five countries put heritability at about 80 percent. [Evidence: strong]
- **It does not predict a fixed future.** Regression describes the past few months. Many children who lose words early regain and build language. Early language is not destiny, and developmental profiles keep shifting through childhood. [Evidence: moderate]
- **It is not always autism.** Hearing loss, some rare medical conditions, and periods of illness can also cost a child skills. That is exactly why an assessment, not a guess, is the right response.

## When to move faster

Most regression is gradual, over weeks. A few situations are worth a same-week call to your doctor rather than a routine referral:

- Loss of skills that is **sudden**, over days.
- Regression together with **staring spells, unusual movements or possible seizures**.
- Regression **after age 3**, especially of many skills at once.
- Loss of **motor** skills (walking, hand use), not only words.

These do not mean something worse is happening. They mean a physician should look sooner, and may add a hearing test, a neurology visit or genetic work-up to the developmental referral.

## What to do in Quebec

The route is the same as for any developmental concern, and the loss of skills is a strong reason to state clearly.

- **Write it down.** The words or skills your child had, roughly when they had them, and when you noticed them gone. Photos and videos on your phone are often timestamped: they are evidence.
- **Book your family doctor or pediatrician**, or call your **CLSC**. Say "my child has lost words and skills; I'd like a developmental referral and a hearing test documented today." The full script is on [What to say to your doctor](/resources/what-to-say-to-your-doctor).
- **Ask about Agir tôt** on the same call. It is Quebec's early-development program for children under 7, free, voluntary, and does not require a diagnosis. [Evidence: official]
- **Do the M-CHAT-R/F** if your child is around 18 to 24 months; it asks directly about the skills that tend to be lost. See [M-CHAT-R/F explained](/resources/m-chat-r-f-explained).

While you wait, keep talking, singing, and playing at your child's pace, and get down to their level. Losing words does not mean losing communication: gestures, pictures and signs do not delay speech, they support it. See [AAC and signs do not delay speech](/resources/aac-and-signs-do-not-delay-speech) and [Waiting is not wait-and-see](/resources/waiting-is-not-wait-and-see).

## This week

- [ ] Make a dated list of the words and skills your child had and no longer uses. Add two or three phone videos, old and recent.
- [ ] Call your doctor or CLSC and ask for a developmental referral and a hearing test, and ask that your concern be written in the file today.
- [ ] Ask about Agir tôt on the same call.

## Sources

- [Autism: Signs and characteristics](https://www.canada.ca/en/public-health/services/diseases/autism-spectrum-disorder-asd/signs-characteristics.html) — Public Health Agency of Canada, accessed 2026
- [Prevalence and onset of regression within autism spectrum disorders: a meta-analytic review](https://doi.org/10.1007/s10803-012-1621-x) — Barger, Campbell and McDonough, Journal of Autism and Developmental Disorders, 2013
- [Autism spectrum disorder: Highlights from the 2019 Canadian Health Survey on Children and Youth](https://www.canada.ca/en/public-health/services/publications/diseases-conditions/autism-spectrum-disorder-canadian-health-survey-children-youth-2019.html) — Public Health Agency of Canada, 2022
- [Association of genetic and environmental factors with autism in a 5-country cohort](https://doi.org/10.1001/jamapsychiatry.2019.1411) — Bai et al., JAMA Psychiatry, 2019
- [Mid-childhood developmental and behavioural outcomes in infants with a family history of autism and/or ADHD](https://pubmed.ncbi.nlm.nih.gov/40923413/) — Charman et al., Journal of Child Psychology and Psychiatry, 2026
- [Agir tôt program](https://www.quebec.ca/en/famille-et-soutien-aux-personnes/enfance/developpement-des-enfants/outils-ressources-developpement-enfants/the-agir-tot-program-early-screening-to-better-address-childrens-needs) — Gouvernement du Québec, accessed 2026