Autism spectrum disorder (ASD) is a neurological and developmental condition that affects brain function, leading to differences in behaviour, communication, social interaction, and learning. Since 2000, autism diagnoses in the United States have risen significantly, raising concerns about what may be driving this trend. Here’s what you need to know.

HOW IS AUTISM DIAGNOSED?

There are no medical tests like blood work or brain scans to diagnose autism. Instead, healthcare providers rely on behavioural observations and interviews.

The term "spectrum" reflects the diverse ways autism presents. Some individuals with ASD may communicate effectively, while others are nonverbal. Sensory sensitivities, repetitive behaviours, and varying levels of independence are also common.

The American Academy of Pediatrics advises screening all children for autism at 18 and 24 months, as symptoms typically emerge around that time. However, in the U.S., the average age of diagnosis remains close to 4 years, while globally, it is around 5 years.

HOW PREVALENT IS AUTISM?

By 2020, autism was diagnosed in 1 in 36 (2.77%) of 8-year-olds in the U.S., an increase from 2.27% in 2018 and 0.66% in 2000, according to the Centers for Disease Control and Prevention (CDC). In England, a 2021 study estimated the rate among children at 1.76%, up from 1.57% in 2009.

Globally, the World Health Organization (WHO) estimates autism prevalence in children at around 1%, up from 0.62% in 2012. However, many countries lack sufficient resources to track and report cases accurately.

WHAT CAUSES AUTISM?

The exact causes of autism remain uncertain. Many scientists believe ASD begins developing in the womb as the fetal brain forms. Research has linked autism to maternal health during pregnancy, birth complications, and environmental factors.

Epigenetics—the study of how environmental influences affect gene expression—is an emerging area of research. Some studies suggest that exposure to air pollution or harmful chemicals before or during pregnancy could trigger genetic mutations associated with autism.

Certain genetic conditions, such as Fragile X syndrome, tuberous sclerosis complex, Phelan-McDermid syndrome, and Prader-Willi syndrome, are associated with an increased risk of autism. Other possible risk factors include having a sibling with autism, parental age at conception, premature birth, low birth weight, jaundice in newborns, complications during pregnancy or delivery, gut microbiome imbalances, and immune system disorders.

Despite claims from some public figures, including Robert F. Kennedy Jr., that childhood vaccines cause autism, scientific research has consistently debunked this theory. The idea originated from a fraudulent study by British researcher Andrew Wakefield in the late 1990s. No credible studies have found a link between autism and vaccines, vaccine ingredients, or medications.

WHY ARE AUTISM DIAGNOSES INCREASING?

Experts attribute the rise in autism diagnoses to expanded screening efforts and broader diagnostic criteria. In 2013, mental health professionals merged three previously separate conditions—autistic disorder, Asperger’s syndrome, and pervasive developmental disorder—under the single diagnosis of autism spectrum disorder.

A study in October 2024 analysing U.S. insurance data found that diagnoses increased most among groups that were historically underdiagnosed, including young adults, females, and racial or ethnic minority children.

Additionally, some autism risk factors have become more common, such as higher parental age and premature births.

IS THERE A CURE OR TREATMENT?

There is no cure for autism, and the condition cannot be reversed. However, early intervention is essential. Supportive therapies, ideally started before age three, can significantly improve communication, cognitive, and social skills.

These interventions may include speech therapy, occupational therapy, social skills training, sensory integration therapy, visual aids, structured routines, individualised education plans, family therapy, and creating a stable, predictable environment.

Source: Reuters