What is autism?

Learn more about Autism Spectrum Disorder and its diagnosis in children


Autism Spectrum Disorder is a condition that impacts a child’s development. This disorder can cause communication problems, social challenges, difficult behaviors or intellectual disability.

Though one in 36 children is diagnosed with autism, it’s important to remember that each child can have very different symptoms and signs of autism. For instance, some children may have social challenges but be gifted learners. Others may have severe challenges learning and communicating with others.

What causes autism?

Autism occurs in the brain, but the exact cause is unknown.

Patricia Evans, M.D., Ph.D., a Professor of Pediatrics, Neurology and Psychiatry; Director of the Neurodevelopmental Disabilities Residency Program at University of Texas at Southwestern School of Medicine (UTSW) and Neurodevelopmental Disability clinical programs at UTSW and clinical Co-Director for the UT Southwestern and Children's Health℠ Center for Autism Care, says that research is showing that there are many different causes which are responsible for autism behaviors.

Most physicians and researchers believe these causes affect both the cerebellum and the frontal lobe of the brain sometime before a child is born until about 2 years of age. The frontal lobe of the brain is located just behind the forehead. The cerebellum is in the back of the brain and supplies important information that the frontal lobe needs to have well-developed functioning for things such as attention, impulse control, fine motor control and mood regulation. Its function helps shape behaviors, learning, personality and movements.

“Lots of things may cause autistic behaviors: Fragile X genes, in-utero exposure to alcohol or drugs, trauma during pregnancy or even bad illnesses during the first few years of life, such as meningitis,” says Dr. Evans. “Anything which potentially alters the cerebella or frontal lobe pathways during these particular crucial first three years of life may cause autistic behaviors.”

Some children may also be more likely to have autism due to their genetics.

Levels of Autism Spectrum Disorder

Beginning in 2013, psychiatrist and psychologists use the fifth edition of Diagnostic and Statistical Manual of Mental Disorders (DSM 5) to diagnose Autism Spectrum Disorder. These new diagnoses don’t use previous names for Autism Spectrum Disorder like Asperger’s Syndrome or Pervasive Developmental Disorder. These terms are out-of-date.

Instead, medical professionals now use levels to describe Autism Spectrum Disorder:

  • Level 3 means children require very substantial support for severe communication and behavior problems
  • Level 2 means children need substantial support for inflexible behaviors or trouble communicating
  • Level 1 means children need support for mild social or communication difficulties

The term social communication disorder was also developed to describe people with very mild social or communication problems or autism-like symptoms.

Dr. Evans encourages any parent who is concerned their child may have autism to talk with their pediatrician. Early diagnosis and treatment can help children reach their full potential.

Learn more

The Center for Autism Care is an interdisciplinary program offering comprehensive patient care and translational medicine for individuals with autism and related neurodevelopmental disorders. Learn more about our program and services.

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