What causes autism and what is the most effective treatment?

First of all, how does autism manifest?

Behavioral: inappropriate social interaction, poor eye contact, compulsive behavior, impulsivity, repetitive movements, self-harm, or persistent repetition of words or actions
Developmental: learning disability or speech delay in a child
Cognitive: intense interest in a limited number of things or problem paying attention
Psychological: unaware of others’ emotions or depression
Also common: anxiety, change in voice, sensitivity to sound, or tic

Autism rates have been going up since we first started diagnosing it as autism.


Why is this?

Initially, we want to say it’s because something is causing it to grow in number. Which might be true, might not be true, there is still research being done on the topic. But something that is interesting to note is diagnosis has changed since 1975.

What is the DSM and who writes it?

The DSM was originally created from collecting census and psychiatric hospital statistics, as well as a United States Army manual.

However, it is controversial.

The National Institute of Mental Health criticizes the manual as being unscientific and subjective. They state that the DSM has a lack of reliability because unlike physical symptoms such as heart disease or AIDS, the measures are on a consensus of clinical symptoms and not any objective laboratory measure. “In the rest of medicine, this would be equivalent to creating diagnostic systems based on the nature of chest pain or the quality of fever.

More and more, psychologists are finding the “biopsychosocial model” to be a more accurate representation of mental distress. The idea is that there are more than just a hand full of superficial criterion that make up mental health. It used to be that biology was considered the biggest factor at play, but these days, with all of the newest research coming out, we are finding that it’s more complex than that, and many, many factors contribute to it.

Here are some examples



The DSM, the Diagnostic and Statistical Manual of Mental Disorders, which is published by the American Psychological Association, is the Bible to the medical community. It is used to diagnose mental disorders.

And it’s changed over time.

DSM-I (1952) Autism-like symptoms were first classified as, “childhood schizophrenic“.

DSM-II (1968) The diagnostic criteria for childhood schizophrenic became broadened to include, “autistic, atypical, and withdrawn behavior.”

DSM-III (1980) “Infantile autism” was now included. Only 6 characteristics were listed and all must have been present in order to receive the diagnosis. “These changes in the field yielded a rapid increase in the number of individuals being diagnosed with autism” (Factor, Freeman, & Kardash, 1989)

DSM-IV (1994) Subtypes were added to the autism diagnosis. It grew from 6 to 16 symptoms and only 6 were needed for diagnosis. Now “qualitative impairment of social interaction” was included. It also included repetitive behavior, an impairment in communication. Onset must have been prior to age 3 though.

Here are other symptoms that were listed:

  1. lack of social or emotional reciprocity
  2. stereotyped and repetitive use of language or idiosyncratic lanaguage
  3. persistent preoccupation with parts of objects.

DSM-5 (2013) Asperger’s Syndrome and Pervasive Developmental Disorder – Not Otherwise Specified, which were previously considered as part of the autism spectrum, were removed.

Now, in order for diagnosis, a person must show all symptoms of social interaction and communication impairment, and additionally, 2 signs of repetitive behavior.

Asperger’s Syndrome has also been added under the umbrella of the autism spectrum.

So this is at least part of the responsibility for why incidence of autism have gone up. The diagnostic criteria has changed to become more broad. It’s not clear in the research if autism prevalence is also going up besides diagnostic criteria changing.

A word on the DSM and it’s credibility: It is my opinion, as someone actually at a university, who is studying mental health care, there is scientific evidence being incorporated more and more into the DSM. But, diagnosis in general is considered by many, past and present day, in the mental health industry as possibly unnecessary, and possibly even damaging.

For example, regardless of if you have autism or asperger’s, regardless of it being genetic, the treatment that is most effective doesn’t drastically change. Applied Behavioral Analysis has been shown to be more most effective, and the sooner the treatment is received, the better.

The most effective treatment for autism: Applied Behavioral Analysis

Specifically the Lovaas model, is a type of Early Intensive Behavioral Intervention (EIBI) created by a psychology professor at UCLA. It incolved breaking down skills to their basic components, rewarding positive performance with praise and reinforcers, and then generalizing skills in a natural setting. The results are gaining language, academic, and basic living skills, while some children can even fully recover!

Applied behavioral analysis includes this model as well as data collection and replacement behavior strategies in order to understand and change behavior.

The evidence for effectiveness


As you can see in the graph above, Early Intensive Behavioral Intervention has been shown to be superior to the control group of children who did not receive the treatment. In 47% of children receiving the treatment for an average of 40 hours a week, they were placed in regular classroom and considered, “indistinguishable” from their peers in follow-up studies.

The unfortunate part of this highly effective treatment is that the estimated cost for 40 hours of treatment a week is about $4,000 a month, with an average yearly cost of $40,000. However, many, many healthcare providers providing a sliding scale payment system based on the income of the family coming in for services.

Now. The biggest question we all have. What causes autism?

Just like the biopsychosocial model, there is not one cause of autism.

  1. It seems to be mostly genetic. It tends to run in families, or the families have related disabilities. It is not a single gene that contributes, and scientists and researchers are currently looking for irregular segments of genetic code. Genetics is currently considered the most significant cause of autism spectrum disorders. Studies of identical twins have shown heritability to be 90%. However, most cases of ASD have no recent evidence of family history



2. Brain shape and structure. Brain scans have shown a different shape and structure of the brain than neurotypical children.

3. Certain medical conditions such as fragile X syndrome (found in 20% of boys with autism), tuberus sclerosis, congenital rubella syndrom, and phenylketonuria.

4. Some ingested harmful substances during pregnancy.

5. De novo copy number variation (CNV) is when deletions and duplication occurs in DNA. This gene has been shown to contribute to 5-10% of cases of ASD.

6. Coding protein mutations are observed in approximately 20% of individuals with autism.

7. Age of the father, because sperm and eggs tend to mutate and wear down as they age. Chromosomal abnormalities also increase with age. ASD children of men over 40 years or older were 5.75 times more likely to have ASD after controlling for year of birth, socioeconomic status, and maternal age. Maternal age was not found to be associated with ASD, but is associated with chromosomal abnormalities.

Egg abnormalities increase with age 





8. Prenatal causes: in a meta-analysis of 40 studies, it has been connected that autism is also contributed to pregnancy such as diabetes, bleeding, psychiatric drugs, and stress.

9. Out of all the non-genetic factors for infectious processes, prenatal viral infection seems to be the principal cause of autism. Exposure to rubella or cytomegalovirus are viruses that activate the mother’s immune response and greatly increases the risk for autism, as well as schizophrenia. If this happens earlier in pregnancy, the chances increase.

10. Fetal testosterone levels in amniotic fluid have exhibited in several reports to be a contributor. This may also explain why boys are more likely to develop ASD than girls. One hypothesis is that it moves brain development closer to ability to see patterns, analyze complex systems, and diminishes communication and empathy. These behaviors are shown in individuals with autism.

11. Lead blood levels are significantly higher in autistic children than neurotypical children, some think this is what leads autistic children to develop pica, eating things such as chalk, glue, or dirt. However, it is not known for sure.

Things that do not cause autism

  1. Vaccines. Study after study after study has not proven a single connection between vaccines and autism. One or two particular studies showed a correlation but they were debunked, and the people who made the studies had their medical licenses taken away for fraud. Most children are diagnosed with autism around the same age that vaccines are introduced, leading parents to believe the vaccine is the cause of ASD. There is no sound evidence of this.
  2. Mother’s age is not correlated with autism.
  3. Ultrasounds
  4. Other things that do not cause autism: gastrointestinal (even though autistic children are more likely to have GI symptoms than atypical children) or immune system abnormalities, “vaccine overload”, allergies, exposure of children to drugs, mercury, dental fillings, infection, certain foods, or heavy metals. (Source, Source)
  5. Mothers not being affectionate with their children. (Bettelheim B. The Empty Fortress: Infantile Autism and the Birth of the Self. Free Press; 1967.)


What causes birth rates to go down in developing countries?

Nobody knows every detail, and the research out there is limited on what has caused fertility rates to go down in developing countries. There are some educated guesses though.

1. As incomes have risen over time, birth rates have been declining. Child labor has gone down as well.





Why is this?

One possibility is what we saw in the industrial revolution in Western countries. As incomes rose, more and more children weren’t needed to work in sweatshops, and instead, families had the luxury to send their children to school instead. Not only did that keep children out of the workforce, but it allowed their children to have increased incomes for their own future because of their newly acquired education.


2. People who live in urban areas tend to have lower birth rates than those in rural areas. Another reason is that populations in rural areas need their children to work in order to survive, and more children provides more income or labor.


3. Increased education rates are correlated with lower birth rates. I think this is correlated because not only are women busy getting and education instead of getting married and having babies, but with their higher education, it increases the likelihood of increased income, because their education provides better paying jobs.

I keep seeing again and again that poverty is related to so many different factors. It seems like if we eliminate poverty, we eliminate a lot of social problems as well.



4. In areas with lower infant mortality rates, we see lower fertility rates. This is because mothers don’t need to have more children to get their desired number of children, because the children were dying as infants.


5. Religion. In majority Muslim countries, there tend to be lower birth rates.


6. Average age of marriage influences birth rates around the world.


7. Contraceptive use around the world is one possible factor but I couldn’t find sound research showing more contraceptive use over time. So we cannot assume this. Also, here’s a look at what methods people are using around the world, as well as, why people choose to not use contraceptives.




The myth that babies should cry it out

“Let the baby cry it out.”
– some parent somewhere probably

The idea of “cry it out” is that if you picked up a baby every time it cried, it would create a dependency on the parents and grow up to be clingy and have attachment problems as an adult.

But in fact, letting a baby cry it out, i.e. leaving it alone and not picking it up, is what actually causes insecure attachment, leading to the adult behaviors of fear of abandonment and separation anxiety.

The second form of attachment is called avoidant attachment, which is also caused by not picking up babies when they cry. This is shown in children who seem detached and uninterested in their caregiver.

Picking up a baby when it cries actually promotes secure (i.e. healthy) attachment, leading them as adults to choose secure partners and understand how to have a healthy relationship.

You cannot spoil a child by loving it too much.

What causes SIDS?

This value begins to screw us up the very first day we are born. When I was taking lifespan developmental psychology in college, I came to the realization that collectivist cultures, with all the problems that come with it too, seems to me, in my personal, worthless opinion, to have it more together than the US.

Hear me out before screaming.

One example, is that the Western world likes to have their babies sleep in cribs in another room, probably because of the cultural value of privacy. But most populations around the world sleep in the same bed as their children, on a hard surface, with the baby lying on its back, which some researchers think partially contributes to their lower cases of SIDS. Japan has the lowest rates of SIDS out of all the industrialized nations, New Zealand being the first.

“Adoption of bed-sharing and room-sharing practices appears to be saving Pacific infants’ lives, even though the New Zealand Cot Death Association has discouraged bed-sharing and not actively promoted room sharing.” – Journal of Paediatrics and Child Health