What is autism?

What is autism?

Autism is a difference. It's not a disease. It happens in the brain. Autism changes the way a person perceives and reacts to their environment and to others. Every autistic person is different, and the level of help they need changes from one person to the next. In short, autism affects communication, interactions with others, very strong interests (such as passions or collections), and a need to do things in a certain precise way. Autistic people sometimes make gestures that may seem strange, or speak differently. Autistic people can have many other differences.

Definition of autism

Autism changes the way a person interacts with their environment and with others. What is autism? It’s a neurodevelopmental disorder. Autism is one of the diagnoses found in the DSM-V, the great reference book in psychiatry. It manifests itself differently from one person to the next, even though autistic people have a lot in common. Basically, it’s a difference in the way the brain works, since it changes the way information is received and processed, and can also lead to challenges in carrying out certain daily activities.

Being autistic is not a physical or mental disease, and of course it’s not contagious. You can’t catch it. You’re born with autism and it stays with you for the rest of your life. You can’t stop being autistic.


ASD is the medical term for autism, short for autism spectrum disorder. Why a spectrum? Because there are so many varieties and differences between them, you could compare it to the color spectrum. Some will say: I’m on the spectrum. Many autistic people wish this wording would stop being used, mainly because of the negative connotation of the word “disorder”.

What are the levels of autism?

A level of autism is not the same as being a little autistic, moderately autistic or very autistic. You’re either autistic or you’re not. The three levels represent the level of support the person needs.

  1. Requires support
  2. Requires strong support
  3. Requires very strong support


What is mild autism?

The definition of mild autism is when the person needs support, but not a lot of support. You may need mild support in one area, for example, communication, and very significant support in another area, such as behaviors, so the person may have several levels of support within the same diagnosis.

What are the characteristics of autism?

Difficulties in social interaction and communication

Some autistic people do not speak and must use other means of communication. Most autistic people can communicate verbally, but that doesn’t mean they don’t have communication challenges.

They may have trouble sustaining a conversation. But it goes beyond that. Communicating is very complex. Humans use unspoken words, expressions, non-verbal cues, intonation, and all these details can be difficult for autistic people to understand and master.

There’s a big lack of instinct when it comes to guessing what the person communicating with us really means, especially if they’re not entirely clear.

Many autistic people don’t know how to start, continue, or end an exchange, or have difficulty doing so. If they do, it may be awkward or inappropriate, despite their best efforts to imitate. Social conventions can be misunderstood.

It can be difficult for autistic people to understand the emotions and intentions of others.

Social interaction can then become a major challenge, isolating the person socially.

Special interests

Autistic people can have very intense, repetitive interests. These used to be called restricted interests. The term has been changed, since there can be several different interests at the same time, and they can change and evolve over time.

These interests can be positive, and their pursuit can lead some autistic people to become true experts in their field.

Some interests are simply playful, and can be a source of motivation or joy.

In some cases, interests can become invasive and detrimental to the person.

Interests can be very diverse. Trains, their routes and timetables, certain animals, a science, a collection, concepts, a game or a fictional element. The list is endless.

90% of autistic people have specific interests.

Repetitive behaviors


Flapping, rocking the body and handling certain objects in a particular way are repetitive behaviours.

Echolalia (vocal repetition)

Some autistic people repeat words or phrases. For some, verbal communication (with the voice) is essentially echolalia.

Routines and rituals

Routines and rituals can be very important for people with autism. They can also emphasize similarity, for example certain colors, particular patterns or symmetry.

Sensory hypersensitivities and hyposensitivities

Although not a diagnostic criterion, sensory hypersensitivities and/or hyposensitivities are very common in people with autism.

Sensory hypersensitivity

Sensory hypersensitivity is an above-average perception of certain senses. It’s not a matter of having superhero senses, it’s that the brain prioritizes this information, which can become overwhelming.

Sensory hyposensitivity

Sensory hyposensitivity is a lower-than-average perception of certain senses. It’s not a matter of having paralysis of the senses, it’s that the brain retains or masks this information, which can become problematic.

Co-occuring conditions

Autism rarely occurs alone. It is usually accompanied by other challenges which, in medical jargon, was defined as comorbidity or associated disorders. It’s preferable to use the word condition, which is more respectful, because co-occuring conditions are highly variable and the word comorbidity defines them poorly and is stigmatizing. Intellectual disability, dyslexia, Tourette’s syndrome, epilepsy, ADHD, the list goes on.

These traits can also be found in people who are not autistic.