“On the spectrum” is an almost unavoidable phrase when discussing autism. But what is the autism spectrum and what does it mean to be on it? Here are the fundamentals of the autism spectrum and the conditions it encompasses.
The autism spectrum refers to the range of previously separately diagnosed conditions that are covered by autism spectrum disorder (ASD)—a group of complex neurodevelopment disorders that are characterized by repetitive behavior patterns and struggles with social communication and interaction that affect daily functioning to different degrees.
Autism is described as a "spectrum" disorder because people with ASD can have a range of symptoms, skills, and levels of disability in functioning. While some children and adults with ASD are capable of performing all of their necessary daily activities independently, for example, others will need a lot of support to perform even basic tasks.
In recent years, The Diagnostic and Statistical Manual of Mental Disorders (specifically the DSM-5, which was published in 2013) has been updated to include Asperger syndrome, childhood disintegrative disorder, and pervasive developmental disorders not otherwise specified (PDD-NOS) as part of ASD, rather than as separate disorders.
While the exact cause of autism spectrum disorder isn’t known, scientists believe it’s likely that both genetics and environment play a role. What we do know about the potential causes of autism spectrum disorder is that:
• Researchers have identified several genes that are associated with the disorder.
• Brain imaging studies of people with ASD have shown differences in the development of several regions of the brains of those affected.
• Some studies suggest that ASD could be caused by disruptions in normal brain growth very early in development which could themselves be the result of defects in genes that control brain development and brain cell communication
• Children born prematurely are more likely to be on the autism spectrum.
And, just as importantly, there are things that we know don’t contribute to the development of autism spectrum disorder, including:
• Parental practices—the theory that parenting choices lead some children to develop ASD has been disproved by scientists.
• Vaccinations—contrary to claims made by some vocal opponents of childhood vaccinations, these have been shown to have no impact on the risk of autism spectrum disorder.
Because ASD is a spectrum, the presentation of symptoms can vary greatly, but most people on the autism spectrum exhibit symptoms by early childhood, often during their first year. Children may also appear to develop neurotypically during the first year and then experience a period of regression between 18 and 24 months, during which time they’ll begin to exhibit symptoms of autism spectrum disorder. In other children, symptoms can present even later, mainly during preschool ages.
While not enough is known about the causes of autism spectrum to determine specific preventative measures that could be taken (if there are any at all) and there is currently no known cure for ASD, early and intensive treatment can make a big difference in the lives of many children on the autism spectrum.