Autism spectrum disorder (ASD) is a condition that affects the ability to interact and communicate. It may have symptoms that are similar to those seen in some brain injuries.

Autism spectrum disorder (ASD) is a group of neurodevelopmental conditions that affect a person’s ability to communicate and interact socially. Symptoms of autism usually develop in early childhood and can involve restricted and repetitive patterns of behavior.

Autism affects the brain in different ways, including causing changes to brain structure and nerve signal processing. Characteristics of autism can sometimes be similar to those seen in a brain injury, and the relationship between the two can be complicated.

It has not been proven that a brain injury can cause autism. However, the relationship between brain injuries and autism is complex, and their symptoms often overlap. Pediatric brain injuries and autism also show some shared biological mechanisms that cause the symptoms. These symptoms can include:

There are different types of brain injuries, and their effects can vary widely. It is not uncommon for some effects of a brain injury to mask symptoms of autism. Having a brain injury may also lead to a delayed autism diagnosis, especially in very young children.

A 2023 study of children who experienced pediatric brain injuries before two years of age showed an increased chance of being diagnosed with ASD. However, the ASD diagnosis was delayed by several years, likely due to symptom overlap with the brain injury. Additionally, all subjects had at least one medical comorbidity, further complicating an ASD diagnosis.

This study was limited but points to the need for more research and early ASD screening in young children who have experienced a brain injury.

The age at which a brain injury occurs does seem to play a role in the development of autism, though this is not a cause-and-effect relationship. Infants or children who experience a brain injury will not necessarily develop autism, and those with autism may never have had a brain injury.

Autism is a developmental disorder, which means that symptoms are present within the first few years of life. When an adult is diagnosed with autism, it is usually a delayed diagnosis that can explain certain behaviors or symptoms that have long been present. It is also possible for a brain injury experienced as an adult to cause symptoms that are similar to ASD behaviors.

Childhood trauma and stress do not cause autism, but they can be connected.

Mental health issues such as depression, anxiety, and PTSD are common comorbidities in those with autism. These issues can lead to a worsening of autism symptoms.

Stressful life events and trauma can be a considerable risk factor for psychological issues, especially when experienced at a very young age. It is not uncommon for a child with ASD to have also experienced a stressful life event, which could lead to more extreme autism symptoms.

The exact cause of autism is not known. The disorder is highly complex and can develop very differently in individuals. It is likely that the cause of autism is a combination of factors.

While the specific cause is unknown, certain factors have been discovered that may cause a child to be more likely to develop autism. These include:

  • Genetic components: Certain gene mutations and common genetic variations have been seen in autistic people.
  • Family history: Having a sibling with ASD or other genetic conditions may increase the chance of having autism.
  • Environmental factors: Exposure to certain chemical agents during pregnancy or other environmental factors, such as air pollutants, could increase the chance of ASD.
  • Birth complications: Low birth weight, premature birth, or neonatal jaundice could increase the chance of autism.

Autism can cause several physical and emotional changes in the brain. It may also affect certain brain regions related to emotions and social function. The changes in these brain regions may account for many symptoms seen in ASD.

Autistic people are developmentally diverse, or neurodiverse. This means they will experience their world in different ways from neurotypical people. In this model, differences are not seen as deficits, and it’s understood that there is no “right” way of thinking or behaving.

An autistic brain is a different type of brain, but its development responds to cultural and environmental influences as with neurotypical brains. Learning to value neurodiversity can help encourage the acceptance and inclusion of all people.

Autism is a complex type of neurodevelopmental disorder that usually shows symptoms in early childhood. While researchers are still exploring its causes, brain injuries have not been found to cause autism.

However, children who have had brain injuries at very young ages may have a higher chance of developing autism. Because the symptoms of brain injuries and autism can overlap, autism screening for young children with brain injuries may be recommended so that early intervention treatments for autism can be utilized.