By Clinical Partners on Friday, 05 September 2025
Category: Child Autism

Do we know what causes autism?

There isn't a single known cause of autism. However, research suggests that a combination of genetic and environmental factors may contribute to its development.

Autism is a neurodevelopmental condition. ASD affects how people communicate, interact, and experience the world. While autism is often present from birth with noticeable characteristics developing in the first three years of life, the exact reasons why some people are autistic and others are not are still being studied.

This resource will explore these potential causes to give you a clearer understanding of how autism might develop.

Table of contents


The causes of autism

Autism doesn't have a single cause. Instead, research points to various factors that can contribute to its development. These factors can be broadly divided into two main categories:

Understanding these potential influences can offer insights into why autism develops. It’s important to note that no one factor alone can explain autism in every individual. Autism is different for every person, which means that causes and symptoms will not always be the same.

Environmental factors

While no single environmental factor is known to cause autism, research suggests that several factors might influence the likelihood of developing autism spectrum disorder.

Here are some key environmental aspects:

Maternal health

Maternal health before and during pregnancy can impact a child’s development. Some conditions may be associated with a higher risk of autism. These may include:

Prenatal exposure

Exposure to certain substances during pregnancy has been studied for its potential link to autism. These substances may include alcohol, drugs, or high levels of stress. While research is ongoing, stress was most associated with higher rates of neurodevelopmental conditions.

Parental age and autism risk

Advanced parental age, particularly older maternal and paternal ages, has been linked with a slightly increased risk of autism. This may be due to genetic changes or other factors associated with ageing. Families considering later parenthood should be aware of this potential risk and consult with healthcare providers.

Birth complications and their impact

Complications during birth have been studied for their association with autism. These complications may include:

While these factors alone do not cause autism, they can contribute to developmental challenges. Proper prenatal care and monitoring can help manage and mitigate risks.

Genetic factors

Genetics play a significant role in the development of autism. While no single gene causes autism, research indicates that both inherited and spontaneous genetic changes can contribute to its development.

Myths about what causes autism

There are a number of myths about what causes autism. It is important to understand these myths, and share the correct statements:

How autism presents differently in individuals

Autism affects people in various ways and to different extents. Understanding these differences helps to appreciate the individuality of each person with autism and fosters a more inclusive environment.

Here are some ways autism can present differently in individuals:

Conditions that often co-occur with autism

Autism often co-occurs with other conditions. Many individuals with autism may also experience conditions such as anxiety, attention deficit hyperactivity disorder (ADHD), or sensory processing disorders.

These additional conditions can influence how autism affects their daily life and interactions. For some, challenges like learning disabilities or developmental delays might also be present.

Each person should be approached with understanding and support. Addressing co-occurring conditions can significantly enhance overall well-being and quality of life.

By acknowledging and treating these additional conditions, we can help autistic individuals thrive and lead fulfilling lives.

Next steps towards an autism diagnosis

If you are looking for support with autism or are interested in assessment for yourself or a loved one, you can contact us on 0203 326 9160 or request a free confidential call back from one of our trained assistant psychologists to discuss how we might be able to help.

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