What causes autism… what doesn’t?

If your child has been diagnosed with autism and you’re wondering what could have caused it, I would strongly recommend that you do not go searching for the answer on the internet.

Over the years writing for SNJ, I’ve come across countless medical articles based on new studies or research that say this could be a ‘risk’ factor for autism, or that can increase the likelihood or is implicated in ASD or  learning disabilities.

I’m sure it’s a fascinating subject to many researchers, but if you’re a parent of a child with autism or actually autistic yourself (I am both) what will concern you more is not what caused it, but who is going to help you cope with it. Maybe some of those research funds could be better spent on providing services for those people living with autism instead.

For a newly diagnosed family wondering 'why', the lack of information and local resources you may be given by your doctor is quite likely to send you looking online for support or reasons. But you may well end up more bewildered than before you started if you start trying to explain how this happened.

Breathing causes autism... doesn't it?

By way of example, I did a brief search just on one site, Medical News Today, which often writes up medical research as articles. Most often the original research paper is locked behind a paywall and even if it wasn't, they are written in such technical terms that it's hard to understand what they mean. There is so much information being pumped out these days, I sometimes wonder if much of it ever gets read by more than a handful of people anyway. It also means it's hard to know immediately what is the most rigorous, peer reviewed, serious research.

Here are just some of the "potential" causes or risks for autism that an array of research articles have recently flagged:

• Autism caused by immune response to viral infection during pregnancy?
  A new study, taking a fresh look at the immune response, has identified a subsection of immune cells that appear to cause certain behaviours linked to autism. It’s a study on mice – those autistic mice that researchers seem to find running around waiting to be experimented on.
• General anaesthetic may disrupt brain development in children (if  pregnant women and children under 3)
• Children of older fathers likely to be 'geeks' Sigh.
• House cleaning chemicals may cause birth defects when either father or mother exposed. Scientists tested a large class of common household chemicals called "quaternary ammonium compounds," or "quats."
• Fever in pregnancy tied to higher risk of autism.. The study - led by the Mailman School of Public Health at Columbia University in New York City, NY - also found that the risk of autism increased in line with the number of fevers reported after 12 weeks of gestation - rising to 300 percent higher risk with reports of three or more fevers.
• Exposure to heavy metals may increase risk of autism: Testing naturally shed baby teeth revealed that children with ASD had much higher levels of lead throughout their development and lower levels of manganese. To determine how much metal the babies' bodies contained before and after birth, the researchers used lasers to analyse the growth rings on the babies' teeth. Like counting tree rings…
• If you’re an autistic girl and your maternal grandmother smoked, you may be more likely to develop autism (check!)
• Genital herpes in pregnancy may raise autism risk for offspring (triggered by mother’s immune response to virus)
• Prenatal stress alters gut bacteria to cause lifelong problems in offspring. (not specifically autism) mother's stress may change the microbiome in a way that negatively affects the baby. (mice again)Researchers found a lower ability to learn and behaviour indicative of higher levels of anxiety among the female offspring of the mice.
• Study links autism to mutations in mitochondrial DNA. (Mitochondria are bean-shaped tiny parts of the cell responsible for producing energy. This earned them the nickname of "powerhouses of the cell.")
• SSRI use in pregnancy linked to speech, language disorders in offspring (SSRIs are a type of anti-depressant). The team found that infants whose mothers had "purchased" (I’m assuming they’d also taken them…tt) at least two SSRI prescriptions during pregnancy were found to be at 37 percent and 63 percent greater risk of speech and language disorders than infants in the unmedicated and unexposed groups, respectively.
• Autism risk increased with prenatal exposure to banned chemicals. While organochlorine use ceased almost 40 years ago in the U.S., the chemicals can persist in the environment for decades; human's primary source of exposure to these chemicals is through diet - mainly consumption of meat and fish - as the compounds accumulate in soil, lake sediment, and animal fat. 80 percent greater autism risk with high prenatal exposure to PCBs
• Is acetaminophen (paracetamol) in pregnancy linked to behavioral problems in offspring? Study results "suggest" prenatal use of acetaminophen by mothers at 18 and 32 weeks of pregnancy was associated with increased risk of conduct problems and hyperactivity symptoms in children, and maternal acetaminophen use at 32 weeks of pregnancy also was associated with higher risk for emotional symptoms in children. So if you ever popped a paracetamol while pregnant (I mean can you even remember?) and your child doesn't have behavioural issues you are clearly bloody lucky(!!)
• Allergies during pregnancy linked with autism, ADHD Studies done in rats…
• Could absence of one protein explain 1 in 3 cases of autism? The scientists had previously shown that people with autism have low levels of a particular protein that plays a key role in brain development. Study done in mice, note, not people.

Don't mention the V word...

And I haven’t even touched on the V word, whether you think it’s definitively been put down and buried six feet under, or whether you cry conspiracy and suppressed studies showing otherwise. And both sides have become are so rabidly vociferous that at any mention of the word ‘vaccination’ on our Facebook page and we are besieged by angry voices on both sides.

Some even go so far as to criticise us for even mentioning it in any context, which I find utterly bizarre. It's almost become a no-go area and this cannot be good. (By the way, while respectful discussion is always welcomed, the next person who trolls us like this will be banned from the Facebook page/Twitter/website immediately, so be warned)

One thing we DO know causes autism is Epilim, unwittingly taken by women with epilepsy during pregnancy, having been told it was safe. This came to light thanks largely to the FACSA campaign led by my online friend, Emma Murphy. The drug now carries a warning label, but there are concerns that the message isn't getting through to young women.

But it's mostly genetic...

We also know that autism has a large inherited genetic component. If one person in the family has it, it's quite likely there are others, whether diagnosed or just suspected. In fact, another new study, reported in The Independent newspaper concludes that Autism is mostly caused by genetic factors, with, "heritability of the condition 33 per cent higher than previously thought."

This study was a reanalysis of data from a previous study on the familial risk of Autism Spectrum Disorder (ASD) and it estimates the heritability to be 83 per cent, according to a study published by JAMA.

The large analysis included 37,570 twin pairs, 2,642,064 full sibling pairs, and 432,281 maternal and 445,531 paternal half-sibling pairs.  Of these, 14,516 children were diagnosed with autism, and the heritability was estimated as 83 per cent, while the non-shared environmental influence was estimated as 17 per cent.

So although that may account for the vast majority of cases of autism, the other 17% still have some explaining to do. In other words, there are more causes than just genetics. In fact, it can seem that just living and breathing is a risk factor for the group of symptoms and behaviours grouped under the autism spectrum.

Aside from Epilim, there will be children with sensitive immune systems that were compromised by any number of environmental or toxicological factors. Additionally, a US drug company is combining with a leading US university in an effort to find a conclusive link between autism and the gut, another thing that is long suspected by many - the 'leaky gut' syndrome.

My tips for dealing with autism research

What causes autism is always going to be a thorny subject for many, but if you want to explore it more, my tips are:

• Look at where the information has come from. Is it a reputable medical/scientific journal?
• Even if it is, check to see if it has been retracted or challenged. Retraction Watch is a fascinating and revealing look inside the scientific process and you would be surprised at just how many studies go on to be withdrawn or corrected.
• Check to see how large the sample for the study is and what the potential weaknesses of the research are.
• Realise that a spectrum condition will have as many causes as presentations and even if one person's autism is genetically predisposed, there could still be external factors that can make it worse or better.
• Be respectful of others' opinions whether you think they're misinformed or not. I think we really need to remember that writing online abuse at one side or another is unnecessarily uncivilised and frankly, it makes you look like a dick. Whatever your beliefs and however backed by science you think they are, you should always behave politely to others or just put the laptop down and step away.

It's not your fault

Most of all, realise that whatever the cause, it isn't your fault. Your job is to take the child you have and spent your energy getting the best help that you can for them, whether educational, social or physical and most likely all of those. Don't blame yourself, that's a hiding to nothing and it will only impair your mental and physical health worrying about it.

Finally, realise that, for the most part, it's not how you got there but where you're going from now. So ignore the medical research and instead, be your own researcher for your child. That means noting things such as food intolerances that may exacerbate the condition, thinking about if there may be other co-morbidities, such as ADHD, anxiety or hypermobility that also need therapy or treatment or  detecting any sensory sensitivities that can cause meltdowns and thinking about how to help. And course the big E, getting the right educational environment.

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Tania Tirraoro

Founder, Co-Director at Special Needs Jungle

Founder of Special Needs Jungle. (She/Her) Parent of two young adults with autism. New grandma. Tania, who is autistic, is a leading SEND advisor, working with the Special Education Consortium, Ofsted, and Whole School SEND. She is also an Advisory Board member of the Royal Holloway, University of London Centre of Gene and Cell Therapy and an Editorial Board member of Springer Nature Gene Therapy journal.
Tania is an experienced broadcast and print journalist & author. She also runs a PR, web & social media consultancy, SocialOro Media.
Tania is a rare disease & chronic pain patient advocate with Ehlers Danlos syndrome.

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