What Is Autism Spectrum Disorder?

Autism spectrum disorder (ASD) is a complex neurodevelopmental difference that is present from birth or emerges in the first years of life. Its exact cause is unknown, but genetics are thought to play a major role and environmental factors are being studied too. Autism is not caused by parenting or by a family's financial situation.

What is autism spectrum disorder?

Autism is thought to stem from differences in the nervous system that affect how the brain is structured or how it works. For simplicity, we sometimes just say “autism” in this article when we mean autism spectrum disorder.

In recent years autism has become a widely discussed special-education category, in Türkiye as much as anywhere else. Over time, the term “autism” has given way to “autism spectrum disorders” (ASD).

What causes autism spectrum disorder?

We still don't know exactly what causes autism spectrum disorder, but there is strong evidence that it has a genetic basis. Which gene or genes are responsible, however, isn't yet known. There are also views that environmental factors may play a part, and a great deal of research is under way into both genetic and environmental influences.

It's not your fault!

Autism has nothing to do with how a child is raised or with a family's financial circumstances. That's why autism spectrum disorder is found in every society, region, ethnic group and kind of family. Experts stress that there is no link between autism and a family's income, lifestyle or level of education.

How common is autism?

Autism is now one of the most frequently diagnosed neurodevelopmental conditions. In earlier decades it was thought to affect about 1 in 500 children. According to the US Centers for Disease Control and Prevention (CDC), an estimated 1 in 150 children were diagnosed in the early 2000s; that figure rose to 1 in 54 in data published in 2020 and 1 in 44 in data published in 2021. In the CDC's report published in 2025, it was around 1 in 31. Part of this rise is explained by broader diagnostic criteria and greater awareness.

Figures on differences between the sexes vary, but the consensus is that autism is more common in boys than in girls; in the 2020 data, it was 4.3 times more common in boys.

Key facts about autism spectrum disorder

• Autism spectrum disorder is thought to have neurological causes. A significant share of autistic people (up to around a third, depending on the source) also have neurological problems such as seizures, involuntary movements or loss of consciousness linked to abnormal electrical activity in the brain.
• Autism spectrum disorder is not a mental illness, although some of its signs can resemble certain mental health conditions.
• Scientific research has shown that autism spectrum disorder is not linked to parenting style or to a family's socio-economic background.
• There is evidence that autism spectrum disorder can be inherited, but the gene or genes behind it have not yet been clearly identified.
• Some autistic people have learning difficulties or intellectual disability to varying degrees. On intelligence tests, certain areas can lag far behind others.
• A small proportion of autistic people (about 10%) have exceptional abilities, such as a very strong memory or musical talent.

Signs of autism

Differences in social communication and interaction

• Not making eye contact, or only briefly
• Not looking up when called by name
• Difficulty using gestures and facial expressions appropriately
• Seeming to be in their own world
• Little interest in children their own age; difficulty building friendships with peers
• Paying more attention to objects and details than to people's faces
• Difficulty responding emotionally
• Finding imitation or pretend play hard
• Not spontaneously sharing feelings and interests

Restricted and repetitive patterns of behaviour and interests

• Repetitive movements (such as rocking or hand-flapping)
• Intense interest in spinning objects
• Playing with toys in unusual ways
• Repetitive, idiosyncratic, monotone speech
• Insisting on sameness
• Narrow and unusual interests
• Ritualistic behaviour
• Over- or under-sensitivity to certain senses such as smell, hearing or touch

If you notice several of these signs in your child, talk to your paediatrician or a child and adolescent psychiatrist. Early diagnosis and early educational support make a real difference.

Nutrition and daily life

Many families pay particular attention to their autistic child's diet and digestion. Always plan any changes to your child's diet, and any use of food supplements, together with your child's doctor.

Related products

If you'd like to learn more about the Trinity Pack, ROOT's three-product daily routine set, take a look at its product page. The Trinity Pack consists of food supplements; it is not a treatment for autism. If you're interested in research on environmental factors, see our list on mercury and chronic illness. Any questions? Get in touch.

This article is for general information only and is not medical advice. Food supplements are not medicines and are not intended to diagnose, treat, cure or prevent any disease.