Vaccination doesn't cause autism, but what does? [closed]

Question

It is proven that vaccinations doesn't cause autism.

But I read from various internet/documentary/newspaper sources which claim that they have personally witnessed their child showing signs of whatever the modern definition of autism is within days of vaccination. In short, their child has changed dramatically for the worse. There's even been a user on this website having the same kind of story.

When these stories arise, I read that such a thing is not possible. However, I've never seen a single article coming to the bottom of what did actually cause autism in those cases!

I understand that vaccination didn't cause autism in those cases, but what did cause it?

Answer 1

Correlation, not causation, is the problem here.

Nothing "causes" autism, it is a natural state for people. It's not even an "illness", it's a combination of personality and behavioral states that we classify as a condition simply because it is outside of "social norms". In short: "it just happens"

The parents have heard that vaccination causes Autism, so immediately after the vaccination they start to look for it and notice some behaviours.

This completely misses the point that those behaviours were already there, unnoticed. That child was always going to show these behaviours, the parent just didn't notice them until prompted. The fact that the vaccines are usually given at around the age a child starts to develop their own individual personality traits only serves to exacerbate this: it's easy to notice newly developing traits. Again, they would have developed anyway, they just happen to be at around the same time.

Note also that Autism is a spectrum not a cross this line diagnosis. Everyone is on the spectrum, it's just that below a certain (rough) point, we stop declaring it as "Autism" and start classifying people as having personality traits. A calm, nerdy, introverted person with low social skills and excellent memory function, for example, is further "up" the scale and more likely to be considered as autistic (or, more likely, having Asbergers) than an outgoing, sociable person with little ability to concentrate (who may be tagged with "ADHD" instead)

Some of these things are personality traits, some are a result of "how autistic" they are, others are both. In essence, though, they are attempt to categories people by their behavior and personality: they do not correspond to a disease or illness.

If you look hard enough you can notice autistic-like behaviour in anybody. I have little ability to emphathise and fairly "tame" emotional response, for example: that doesn't make me Autistic, but it perhaps suggests I'm further "up" the spectrum than somebody more emotionally involved: but I am, for the most part, a well adjusted individual, socially and behaviourally.

In short, they're looking for those behaviours and associating them with the vaccine. The behaviours existed before, and are just part of human existence.

Answer 2

Causes of autism spectrum disorder

The exact causes of autism spectrum disorder (ASD) are unknown, although it is thought that several complex genetic and environmental factors are involved.

The causes of ASD can be described in two ways:

• Primary ASD (also known as idiopathic ASD) – where no underlying factors can be identified to explain why ASD has developed.
• Secondary ASD – where an underlying medical condition or environmental factor thought to increase the risk of ASD is identified.

About 90% of cases of ASD are primary, and about 10% are secondary.

Risk factors

Factors thought to increase the risk of developing ASD, known as ‘risk factors’, can usually be divided into five main categories:

• Genetic factors – certain genetic mutations may make a child more likely to develop ASD.
  
• Environmental factors – during pregnancy, a child may be exposed to certain environmental factors that could increase the risk of developing ASD.
  
• Psychological factors – people with ASD may think in certain ways that contribute towards their symptoms.
  
• Neurological factors – specific problems with the development of the brain and nervous system could contribute to the symptoms of ASD.
  
• Other health conditions – certain health conditions associated with higher rates of ASD.
  

Autism spectrum disorder - Causes
NHS Choices. Page last reviewed: 18/12/2013.

See the source for a detailed description of all five risk factors.

The causes of autism are still being investigated. Many experts believe that the pattern of behaviour from which autism is diagnosed may not result from a single cause. There is strong evidence to suggest that autism can be caused by a variety of physical factors, all of which affect brain development - it is not due to emotional deprivation or the way a person has been brought up.

There is evidence to suggest that genetic factors are responsible for some forms of autism. Scientists have been attempting to identify which genes might be implicated in autism for some years.

Autism is likely to have multiple genes responsible rather than a single gene. The difficulty of establishing gene involvement is compounded by the interaction of genes and by their interaction with environmental factors. For these reasons genetic testing to diagnose a pre-disposition to an autistic spectrum disorder is not, at present, possible.

Position statement: causes of autism
National Autistic Society, 17 October 2011

There is no known single cause for autism spectrum disorder, but it is generally accepted that it is caused by abnormalities in brain structure or function. Brain scans show differences in the shape and structure of the brain in children with autism compared to in neurotypical children. Researchers are investigating a number of theories, including the links among heredity, genetics and medical problems.

In many families, there appears to be a pattern of autism or related disabilities, further supporting the theory that the disorder has a genetic basis. While no one gene has been identified as causing autism, researchers are searching for irregular segments of genetic code that children with autism may have inherited. It also appears that some children are born with a susceptibility to autism, but researchers have not yet identified a single “trigger” that causes autism to develop.

Other researchers are investigating the possibility that under certain conditions, a cluster of unstable genes may interfere with brain development, resulting in autism. Still other researchers are investigating problems during pregnancy or delivery as well as environmental factors such as viral infections, metabolic imbalances and exposure to chemicals.

About Autism > Causes
Autism Society