What is autism? The developmental disability Tallulah Willis was diagnosed with as an adult

Tallulah Willis has publicly revealed that she was diagnosed with autism.

The 30-year-old actress hinted at her struggle with the developmental disability when she took to Instagram on 15 March to post a throwback video from her childhood. In the video, a young Tallulah was seen cradling and stroking her dad’s face as he held her on his hip during a red carpet interview.

“Tell me you’re autistic without telling me you’re autistic,” her caption read.

Having never heard of her diagnosis prior, commenters flocked to Tallulah’s post to question whether she found out when she was a child or an adult.

One follower asked: “If you’re open to sharing, did you get diagnosed as a child?”

“Actually this is the first time I’ve ever publicly shared my diagnosis. Found out this summer and it’s changed my life,” Tallulah revealed.

Autism Spectrum Disorder is a developmental disability that stems from differences in the brain. According to the Centers for Disease Control and Prevention (CDC), known causes are often genetic conditions. However, other causes are not yet known. “Scientists believe there are multiple causes of ASD that act together to change the most common ways people develop,” the CDC states.

“People with ASD may behave, communicate, interact, and learn in ways that are different from most other people,” the CDC continues. “There is often nothing about how they look that sets them apart from other people.”

ASD abilities range from person to person. One individual may require assistance in their daily life, while another individual with ASD may be able to go about their days with no support.

The CDC explains: “ASD begins before the age of three years and can last throughout a person’s life, although symptoms may improve over time. Some children show ASD symptoms within the first 12 months of life. In others, symptoms may not show up until 24 months of age or later.”

“People with ASD often have problems with social communication and interaction, and restricted or repetitive behaviors or interests. People with ASD may also have different ways of learning, moving, or paying attention,” the CDC adds.

Adults may come to find out they have ASD from other conditions like anxiety, depression, and attention-deficit/hyperactivity disorder – all of which are more likely to occur in individuals with ASD than those without.

There are no medical tests that determine whether a person has ASD. Rather than a blood test, a doctor examines a child’s behaviour and development. A diagnosis is more reliable once the child is two years old, but most children aren’t diagnosed for certain until they are older.

Per an Autism Speaks report, it’s not unlikely for adults to be diagnosed with ASD. “Adults typically seek out a first diagnosis because they want to understand themselves. They often feel that people don’t understand them, and sometimes have a history of being bullied, teased or misunderstood,” the report states.

“They may have a demanding job where they’re exhausted from the social demands of the job. Or they may have children and struggle to deal with the unpredictability of meeting somebody else’s needs,” Autism Speaks continued. “They feel like people are giving them feedback that they’re not doing things right when they think they are.”

An adult with undiagnosed ASD is more likely to be “pretty strong intellectually”. They may exhibit “executive functioning problems,” but they are less likely to have “significant cognitive impairment”.

“Undiagnosed adults also tend to have far fewer overt repetitive behaviors than kids do,” Autism Speaks found. “They’re not clapping their hands, spinning or doing things we might see in a three year old. The sensory issues they experience are often very real, but they’re more subtle.”

Unlike children diagnosed with ASD, adults with ASD don’t usually have the same language disabilities. Children are typically referred to ASD diagnoses due to language impairments like repeating words, making grammatical errors, or reciting sentences from videos they’ve watched.

According to Autism Speaks, the diagnosis process for adults begins with a virtual meeting, followed by a discussion with someone who was well acquainted with the individual when they were a child. This is necessary since the disability is developmental, and a doctor is meant to look for a “something that has always been there but may not have caused difficulty until later in life”.

The next step is a three-hour face-to-face examination. “For adults, we do some standard cognitive tasks to see the person in action, because so many of the issues that come up for autistic adults are related to executive functioning and making judgments,” the organisation explained.

The final steps include an Autism Diagnostic Observation Schedule (ADOS) assessment to test an adult’s difficulty with certain tasks and a social-emotional functioning interview, questioning the details of their day-to-day lives.

Treatments for individuals with ASD are designed to fit an individual’s needs specifically. Professional services are recommended and eligibility for work accommodations.

Autism Speaks suggests any person who suspects they have autism reach out to a therapist, psychologist, or psychiatrist. Some clinics offer assessments that are covered by insurance, but private practices often do not.