Health influencer peddles baseless claims about origins of autism and ADHD

^{By Eiddwen Jeffery}

A US health influencer with more than 8 million online followers has falsely claimed that the neurological conditions autism and attention deficit hyperactivity disorder (ADHD) are “not genetic or gut related” but caused by metal particles in the brain.

“What really causes ADHD is mercury and aluminium settling in the brain’s cerebral midline canal, which divides the brain’s left hemisphere from the right, along with some additional metals scattered in other areas of the brain”, he wrote in an August 2024 Facebook post. “It’s the same cause as autism”. 

His posts on the subject, which have been shared by Australian users, claim the metals block signals between the cerebral hemispheres, forcing the brain to use alternative neural pathways for actions such as talking and listening.

But the claims lack any scientific evidence and implicate a part of the brain that is not responsible for communication. Moreover, there is substantial evidence that both autism and ADHD are strongly associated with genetics.

The person behind the posts is Anthony William, a self-proclaimed “chronic illness expert” and spiritual medium who says his medical expertise is drawn solely from conversing with the “Spirit of Compassion”.

His website says he is not a “licensed healthcare professional, practitioner or provider of any kind”, and his 2022 book, Medical Medium Brain Saver, in which he details his autism and ADHD claims, contains no references to any studies or sources.

No evidence that metals in the brain cause autism or ADHD

Andrew Whitehouse, a leading Australian autism researcher and the director of CliniKids at The Kids Research Institute Australia, told RMIT Lookout that early exposure to toxic metals, such as lead, can “interfere with neuronal growth” but does not result in physical particles settling in the brain and causing autism or ADHD.

While noting there was evidence that prenatal exposure to mercury could be neurotoxic, he said scientific reviews had found that the association between mercury and neurodevelopment was weak. 

Professor Whitehouse cited two studies that found no link between early mercury exposure and ADHD or autism. There has been little research examining the role of aluminium exposure, he added.

Valsamma Eapen, chair of infant, child and adolescent psychiatry at the University of NSW, told RMIT Lookout there was “no robust evidence to suggest the specific involvement of mercury and aluminium in the 'midbrain canal' blocking communications”. 

She said there was some evidence to suggest an association between higher levels of certain heavy metals and individuals with autism and ADHD, but cautioned that “association does not mean causation”.

Although exposure to heavy metals can impact brain function and development, such effects would mostly be a contributing factor to autism and ADHD in the context of other developmental vulnerabilities, Professor Eapen said, highlighting the role of genetic and other environmental factors.

‘Midline canal’ is not responsible for communication

In numerous social media posts, including a longer Facebook video from 2022, Mr William refers to the role of the “cerebral midline canal” in communication and claims the gap seals up with age, trapping metal particles in the brain.

But the midline canal is not a term typically used in reference to the brain. The deep groove separating the cerebral hemispheres is more commonly known as the longitudinal fissure, according to Robin Laycock, a cognitive and affective neuroscientist at RMIT University. 

The fissure develops in the womb and neither changes substantially during development nor closes up with age, he said, noting that although the two hemispheres could fuse or fail to properly form, such cases were extremely rare. 

When asked if a change to the longitudinal fissure would affect verbal communication, as suggested by Mr William, Dr Laycock said, “communication between the two hemispheres is not so much a function of the longitudinal fissure, but the corpus callosum”, a dense set of fibres that connects the brain's hemispheres. 

What we know about the causes of autism and ADHD 

There is significant evidence that genetics contribute strongly to both autism and ADHD. 

Meta-analyses have shown that 80 per cent of the variability in ADHD traits are the result of genetic factors. For autism, genetics are estimated to account for 40-90 per cent of the variability in traits, while more than 100 genes and genomic regions have been associated with the condition.

Environmental factors are also believed to play a part, with several studies having found an association between autism and prenatal exposure to anti-seizure medications, for example.

ADHD has been linked to factors such as smoking during pregnancy, extremely premature birth and, in rare circumstances, extreme deprivation or traumatic brain injury early in life, according to the World Federation of ADHD, a global network of experts in the condition. 

In 2021, the federation summarised the available evidence in a consensus statement that said most cases of ADHD were “caused by the combined effects of many genetic and environmental risks”.

While gut health and diet are not considered to be a primary cause for either autism or ADHD, there is emerging research of a potential brain-gut connection for both conditions.

This is not the first time Mr William has shared unsubstantiated health advice, having falsely claimed that celery juice helps heal the painful condition fibromyalgia.