9 Things You May Not Know About Autism

It’s possible for children as young as 18 months to be diagnosed with autism spectrum disorder. But most diagnoses occur at 24 months or older, at which point the diagnosis is considered to be very reliable. "Before that, kids with autism will show deficits in social communication, but it’s appropriate for their age," says Alycia Halladay, PhD, chief science officer at the Autism Science Foundation in New York City.

There’s no medical or blood test for autism, so doctors typically evaluate a child’s behavior through a developmental screening and then a comprehensive diagnostic evaluation, which can include hearing, vision, and neurological tests. The doctor may also recommend a follow-up visit to a specialist, such as a developmental pediatrician

Symptoms of autism spectrum disorder can vary widely depending on the individual. For some people, symptoms of the disorder are mild, while they may be more pronounced in others. But symptoms of ASD generally tend to involve communication skills and social behaviors, such as being extremely introverted, not wanting to play with other children, or not making eye contact. Kids with autism spectrum disorder may repeat certain behaviors (such as flapping their hands) over and over again, or they may become obsessed with a particular toy, like Thomas the Train. Lack of verbal skills is one of the most well known symptoms (20 to 30% of people with ASD are estimated to be nonverbal), but this isn’t always the case. Other red flags for parents: if a child is very sensitive to noise, throws intense tantrums, doesn’t respond spoken to, doesn’t point at interesting objects, or doesn’t play “pretend” games by 18 months

Stats on autism can vary, but the CDC estimates that about one in 68 children in the United States had an autism spectrum disorder between 2000 and 2010, compared to one in 150 in 2000. There’s a lot of disagreement among experts about whether or not this increase reflects more people actually having an autism spectrum disorder, or more diagnoses due to increased awareness and screenings.

"I think it could be a combination of prevalence and diagnosis," says Alexandra Perryman, a board-certified behavior analyst and lead clinician at the Western Psychiatric Institute and Clinic of UPMC Theiss Early Autism Program. "The criteria for diagnosis is changing, and that’s lead to more children being diagnosed." She adds that the increase in general awareness among everyone in a child’s life—from parents to daycare workers to pediatricians—probably also helps.

"There is definitely evidence to say that changing diagnosis and better awareness has a significant effect," says Halladay. "But it probably isn’t 100% of the story." In other words, more research is needed to determine what exactly is behind these figures

Autism spectrum disorders are about 4.5 times more common in boys than girls, but it’s a stereotype that all autistic people are white men. People of all races and ethnicities can be diagnosed with an autism spectrum disorder. And although boys do tend to be diagnosed earlier and more often than girls, there’s growing evidence that the number of ASD cases in girls is under-diagnosed.

Fewer ASD screenings for young girls may be due in part by what people expect of young boys versus girls, says Perryman. "A lot of times, people think ‘Girls are shy, it’s okay if they’re not talking right now, she prefers to just play by herself,’" she says. "And boys, the stereotype is they should be playing with friends and running around and roughhousing, and when they see a kid not wanting to play with his peers, it’s more noticeable."

Scientists don’t know exactly what causes autism. Most experts agree that a combination of genetic and environmental factors increase a child’s risk of developing an autism spectrum disorder, but there are still a lot of unknowns. There’s emerging evidence that children may start to develop autism before they’re born. "This is a really critical time point," explains Halladay. "We know it’s pre-birth because we have identified cells in brains of people with autism that are different. Those cells develop before the baby is born."

Research seems to suggest that certain drugs taken during pregnancy can increase risk (such as valproic acid, a prescription drug used to treat epilepsy). Older parents also have a higher chance of having a child with autism, and a person is more likely to have an autism spectrum disorder if they have a sibling with ASD.

People with autism spectrum disorders have a greater risk of other health conditions, as well. About 2% of people with ASD have fragile X syndrome, a genetic disorder that causes intellectual disability, and as many as 39% of autistic people have epilepsy by the time they’re adults. What’s more, people with ASD may also be more prone to anxiety, ADHD, depression, sleeping problems, allergies, and stomach issues.

Although there continues to be a lot of disagreement about the link between childhood vaccinations and autism, it’s been determined to be a myth by study after study.

"Vaccines are not one of the causes," says Halladay. The theory first began after a small 1998 study claimed to find a link between the measles, mumps, and rubella (MMR) vaccine and autism. That study has since been deemed flawed, and the original journal it was published in retracted it. Thimerosal, another vaccine ingredient once thought to increase risk of autism, has also not been linked to ASD (and since 2001, it has been reduced or eliminated in vaccines). Subsequent research has consistently found vaccines to be safe and identified no connection between childhood vaccinations and autism.

There’s no cure for autism, but early intervention may help autistic kids thrive. (Important note: many autistic adults feel they don't need to be cured.) Applied behavioral analysis (ABA) and occupational, speech, and physical therapies are frequently used. ABA probably has the most evidence, says Perryman, who is a board-certified behavior analyst herself. "It works by identifying the reasons why kids are engaging in behaviors," she says. For example, activities like throwing tantrums and flapping hands are often triggered by the frustration of not being able to express that you’re hungry.

Making better eye contact can also be taught. "The earlier the child is treated, the more gains that are seen with communication and social skills," says Perryman.

There are also medications available to help manage some of the symptoms of ASD, such as antidepressants, anti-seizure medication, or medications to help difficulty focusing.

Think your child might have an autism spectrum disorder? You can request a free evaluation from the public early childhood system in your state. To find the best contact in your area, visit The Early Childhood Technical Assistance Center’s website. If your child qualifies, you may also be able to benefit from free early interventions.

“Everyone is entitled to services, regardless of age,” says Halladay. “Each person is entitled to sit down with a school district and say, this is what I need, this is what you can provide, what our short term and long term goals.”

These interventions are provided through school districts, and there may be a wait list. Some parents choose private services, which are not free.