Autism spectrum

The autism spectrum, often called just autism or autism spectrum disorder, refers to a disorder of brain development caused by differences in the structure of the brain. Autism changes how someone thinks, understands the world, moves, communicates, and socializes. Autism is a spectrum disorder, which means that every person with autism will have different symptoms and different severity of symptoms. Some autistic people may need a lot of help with one thing. Other autistic people may not need help with the same thing. It may be easy to tell when someone is autistic, or it may not be.

The main areas of difference from non-autistic people is thinking differences (how people think and understand the world), sensory processing differences (how people react to stimuli), motor differences, communication differences, developmental differences, and socializing differences.

Signs of autism are usually present when a child is around two or three, but some people are not diagnosed until later. Some people are not diagnosed until they are adults. There is no cure for autism and many autistic people do not want a cure. They want to be accepted as different. This is called neurodiversity. Autistic people who want their differences to be accepted may be part of the autism rights movement.

History

Early history 
The word “autism” comes from the Greek word “autos”, meaning “self.” The term describes conditions in which a person is removed from social interaction: an “isolated self”. The term "autism" was first used by a psychiatrist named Eugen Bleuler in 1911 to describe one group of symptoms of schizophrenia. Sigmund Freud considered this idea and thought it was related to narcissism.

Discovery 
In the 1940s, two researchers were studying autism in different countries; Hans Asperger in Austria and Leo Kanner in the United States.

In 1943 Leo Kanner (a doctor from Johns Hopkins University) did a study of 11 children. He found out that they had difficulties such as changing environments, being sensitive to certain stimuli, having speech problems, and allergies to food. Later he named the children’s condition “early infantile autism”, now called autism spectrum disorder.

Hans Asperger was doing a similar study in Austria He found they also had “[...] a lack of empathy, little ability to form friendships, one-sided conversation, intense absorption in a special interest and clumsy movements”. It used to be thought that Hans Asperger and Leo Kanner were looking at different children and that Hans Asperger found a "mild form" of autism. This was the initial justification for Asperger syndrome. However, later research found that they were doing research on similar populations. Hans Asperger was also doing research in Nazi-controlled Austria, which believed in eugenics. Eugenics is the idea that some people are better than others. In Nazi-controlled Europe, people who were considered "lesser" were murdered, imprisoned, and discriminated against. Recent research has discovered that Hans Asperger sent children with disabilities to be murdered.

The refrigerator mother theory 

In 1943 and 1949, Kanner described the children he studied in scientific papers. In these papers, he wrote that he thought the children's parents were not loving them enough. He wrote that this might be part of the reason why the children had autism. For example, in 1949 he wrote that the children's parents showed no warmth, or love, to their children. He thought the parents were so "cold" that he compared them to refrigerators:“[The children] were left neatly in refrigerators which did not defrost. Their withdrawal seems to be an act of turning away from such a situation to seek comfort in solitude”.This idea became known as the refrigerator mother theory. For decades parents were blamed for causing their children's autism by not loving their children enough. By now, we know this is not true.

Later history 
Schizophrenia and autism were linked in many researchers’ studies. It was in the 1960s when medical professionals started to see these two disorders as separate conditions. Since 1980, Kanner’s so-called "early infantile autism" is listed in the Diagnostic and Statistical Manual of Mental Disorders (DSM). However, the DSM came out with a more accurate definition of autism in 1987. Since then, early infantile autism is called autism disorder. For the first time the DSM also introduced standardized criteria to diagnose autism. The fourth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM) expanded the definition of autism and included milder cases of autism. Asperger’s syndrome was added as a type of autism in 1994.

Recent history 
Autism used to be considered different conditions. Some diagnoses in the past include: Classical autism, Asperger's syndrome, Pervasive Developmental Disorder Not Otherwise Specified (PDD-NOS). However, none of these separate diagnoses exist anymore. Both the US DSM-V (2013) and the ICD-11 (2022) have combined the existing diagnoses into one diagnosis: Autism spectrum disorder.

This happened because doctors found that these diagnoses were frequently used in different ways. For example, one person could get a diagnosis of classical autism from one doctor, Asperger's from a second doctor, and PDD-NOS from a third doctor. This was hurting people's ability to access services and supports.

Additionally, recent research shows that Hans Asperger sent autistic children to be murdered by Nazis. Because of this, the diagnosis is less frequently used, and is not preferred by many autistic people.

Symptoms

Persistent Deficits 
Both the ICD-11 and the DSM-5 define autism by deficits. Deficits are areas where autistic people are not as good at something as non-autistic people. Autistic people have disagreed with how autism is defined by deficits and not by differences. In Welcome to the Autistic Community, a Simple English book, about being autistic, they refer to differences, rather than symptoms or deficits. Researchers and autistic advocates are working together on creating a way to diagnose that is based on autistic people's experiences of autism and is not deficit based.

The symptoms or characteristics of autism can look different depending on how old you are. Doctors are supposed to keep that in mind while diagnosing autism. For example, a toddler and an adult, while they both are autistic, would express it very differently.

These symptoms must be persistent. Persistent means that these symptoms must keep happening over a long span of time. If a symptom only happened once, it wouldn't be persistent. Autism is life-long.

Onset (When symptoms start) 
These are the two areas where symptoms must be present to diagnose autism spectrum disorders.

Both the ICD-11 and DSM-5 say that there have to be some symptoms in childhood, but that sometimes symptoms won't fully manifest until later.

Social Interaction and Communication 
Difficulty in social interactions and communicating with each other.

Some examples are:
 may not understand body language or other forms of non-verbal communication
 may not like to make eye contact
 may have difficulty making friends
 may prefer being alone, or not interested in making friends
 may not speak or speak less than others
 may have difficulty in knowing how other people feel

Restricted, repetitive and inflexible behavior 
This term means behavior that happens over and over again and it is difficult to change. This can happen in many different situations: talking, routine, body movements, and others.

Some examples include:
 may have trouble dealing with changes in routine or unexpected events.
 may do the same things at the same time or the same places
 may be overly concerned with rules while playing
 may enjoy lining up or sorting objects
 may do the same body movements repeatedly (stimming)
 rocking, walking on tiptoes, flapping hands, and others
 may have special interests (areas where the person is super interested in something)
 Sensitivity
 Greater or lesser sensitivity to certain sensory experiences like smells, noises, or touch.

Affects the persons life 
For a diagnosis, the symptoms must affect the person's life. This can include social, school, job, or other areas. For example, someone having trouble making friends, or having trouble getting a job.

In 2021, an online survey of 16-90 year-olds showed that autistic men are more likely to be bisexual, while autistic women are more likely to be homosexual.

NHS England calculated in 2022 that autistic people, without a learning disability, were more likely to die and lived, on average, about 5 years less than other people.

Frequency 
There are many studies on how many autistic people are out there. In the United States, the CDC does studies. In 2018, they found that 1 in 44 children are autistic. That is about 2%. According to the World Health Organization (WHO), 1 in 100 children worldwide are diagnosed with autism. This number keeps going up. Many people wonder why there are more and more autistic children. Some people think that something is causing it. But really, most scientists think that we are getting better at diagnosing autism. More doctors know about autism and can diagnose children that they see. More people have access to medical care and can get a diagnosis.

Under-diagnosis 
In the past, autism was considered a disorder for white boys. Still, more white boys are diagnosed, and it is 4 times more diagnosed in boys than in girls.Girls and children of color are under-diagnosed. Under-diagnosed means that girls and people of color are not diagnosed as often as they should be. This means that many girls and children of color do not get a diagnosis. They may receive a different diagnosis, or they may not receive any diagnosis at all. Now, more girls and children of color are getting diagnosed. Many women and people of color also get a diagnosis or realize they are autistic as adults. Another reason might be that girls are more likely to mask or camouflage their autism to fit in.

Causes 
Scientists do not know exactly what causes autism. There may be many different causes for autism. Scientists do know about some things that make a person more likely to have an Autism Spectrum Disorder.

Genes 
Autism may be caused by genes. Genes are passed on from parents to children. If you have an autistic family member, you are more likely to be autistic. Some doctors look for the genes that cause autism. This is criticized by some autistic people.

Differences in the brain 
Some researchers think that differences in the brain may cause autism. However, no one type of abnormal functioning of the brain is the only cause of autism. Still, scientists found some differences between the brains of autistic people and the brains of people who are not autistic. Autistic people and non-autistic people might use their brain differently. Autistic people might use certain parts of the brain more than non-autistic people.

A study by a group at Stanford Medicine found that there are structural and functional differences in the mesolimbic reward pathway of children with autism, particularly in the connections between the nucleus accumbens and the ventral tegmental area. The mesolimbic reward pathway is the pathway that allows people to find social interactions and other stimuli rewarding. In this pathway, the nucleus accumbens are involved in processing social stimuli and the ventral tegmental area is where dopaminergic neurons, the neurons that respond to dopamine, are concentrated. The abnormalities in this pathway prevent children on the autism spectrum from finding social interactions rewarding, which can contribute to how they interact with others. This means that they are less motivated to interact with other people which can contribute to their deficits in social interaction. Furthermore, these differences contribute to the severity of their symptoms.

Risk Factors During Pregnancy 
There are some factors during pregnancy that can make autism more likely. The likelihood of autism increases if the mother uses thalidomide, valproic acid or drinks too much alcohol during pregnancy. The risk for autism also increases with the age of father and mother at the time of pregnancy.

Maternal folate deficiency is also a prenatal and perinatal factor that is a risk factor for autism. Folate (i.e., Folic Acid) is a micronutrient that is a type of B vitamin. This nutrient can play a vital role in a uterus’s development and the production of healthy red blood cells. A person can obtain folate in their diet by consuming fruits and vegetables as various supplements. It was hypothesized that maternal supplementation of folate can help reduce a baby’s risk of developing ASD. Research on the relationship between folate and Autism Spectrum Disorder has had mixed results. Studies conducted by Raghavan et al. (2017) and Levine et al. (2018) found that when a mother was exposed to folate through supplements before and/or during pregnancy, there was a reduced risk of the child having Autism. However, in Egorova et al.’s (2020) study of the biomarkers found in the blood serum samples of mothers of children with Autism, it was found that higher levels of folate were correlated with an increased risk of ASD.

Debunked Theories 
Some thing don't cause autism but people used to think they did.

"Refrigerator Mother" Theory 
Scientists used to think that the parents caused autism by not loving their child enough. This is not true.

Scientists know that parents do not cause their children's autism.

Vaccines 
Scientists do know for sure that vaccines do not cause autism. Vaccines do not even make a person more likely to have autism, even if they are already likely to have autism before they get their vaccines.

One paper said in 1997 that vaccines caused autism. This study did not do research the right way. Many studies have shown that this is not true. Vaccines do not cause autism. This paper was retracted, which means that it was unpublished because it was incorrect.

Diagnosis 
Diagnosing autism can be hard because there is no medical test like a blood test. Instead, an evaluation is made by a team of doctors and other health professionals who are experienced in autism and know the person trying to get diagnosed.

Diagnosis in children 
A reliable diagnosis can first be given at the age of two. At the age of 18 and 24 months, children should get a check-up. If anything wrong is noticed, a further evaluation is done. In this, a team of professionals will talk to the child’s guardians about the child’s behaviour and see what they are like in different settings. This may also include behavioural or physical assessments as well as intelligence tests or developmental tests. A good, detailed history of the child is often very useful in getting a diagnosis.

Diagnosis in adults 
Autism can be diagnosed in adults as well as children. This can be difficult because autism has symptoms that can also be a part of other disorders, such as OCD, that may have appeared by adulthood. An expert will usually ask the adult about concerns, challenges in life (such as socially or behaviourally) as well as standardised testing in these areas. They also often ask for a developmental history.

Diagnostic and Statistical Manual (DSM-5) 
In 2013, the American Psychiatric Association published the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-V). In order to be diagnosed with autism, a person must fulfill two standardized criteria. It is important that individuals must show symptoms from early childhood, even if those symptoms are recognized later. These symptoms have to limit everyday functioning. These symptoms also cannot be explained by an intellectual disability or a developmental delay.

Autism Spectrum Disorder is characterized by difficulties in social interaction, verbal and nonverbal communication and repetitive behaviours.

Co-occurring conditions 
Autism spectrum disorder includes a wide range of symptoms, skills and levels of disability. Some autistic people also have learning disabilities, mental health issues or other conditions. This means that autism can also co-occur with other conditions and symptoms of the following disorders:
 Attention-deficit hyperactivity disorder
 Obsessive-compulsive disorder
 Learning disability
 Intellectual disability
 Anxiety disorder

In the DSM-V, making a diagnosis of autism means a formal diagnosis of other psychiatric disorders cannot be made. Therefore, other mental health conditions may be undiagnosed in an autistic person, because it is impossible to make a comorbid clinical diagnosis.

Treatment 
Since autism is a spectrum, every person with autism is different. Different treatments help different people. There are a few different categories of treatment. The main ones are medication, different therapies and diets. The treatment is fitted depending on what a person with autism needs.

Medication 
It is still unclear what causes autism. There may be a few causes. At the moment, it is only possible to lower the symptoms of autism. A full recovery from autism is not possible. If therapies cannot reduce the symptoms of autism, medications are used additionally. Often, several medications are used at the same time to treat different symptoms of autism.

Selective Serotonin Reuptake Inhibitors (SSRI) 
Serotonin is a chemical messenger that transports signals between cells and is very important for normal function, such as with sensory perception, memory, learning, and sleep, all of which are impaired in autistic people.

Researchers have not yet found a link between autism and serotonin, although they have been successful in treating autism with SSRIs, which stop cells from absorbing serotonin, meaning more is used for signals.

They can be used to treat repetitive behaviour, aggression, hyperactive behaviour and outbursts of anger. The SSRIs can have many side-effects. Usually the medication is better tolerated by adults than by children. Examples of SSRIs are Clomipramine, Fluvoxamine, Sertraline, Venlafaxine, Trazodone and Mirtazapine.

Antipsychotic medication 
Dopamine is a chemical messenger in the brain. It helps to do movements, release hormones and strengthen cognitive abilities. Researchers found that increasing the amount of dopamine in the brain will worsen the symptoms of autism. Substances that help to reduce symptoms of autism are the antipsychotic drugs. There are two types of antipsychotic medications. One of the types are typical antipsychotics. They block the sites where dopamine would bind to a cell. Atypical antipsychotic drugs on the other hand block the sites where dopamine or serotonin would bind to a cell. Antipsychotic medicine is the most successful treatment for excitability in autism. It can also help to reduce aggression, self-injury, hyperactivity and repetitive behaviours, although it may have many side-effects. Originally, antipsychotic medications were used to treat mental disorders like depression, bipolar disorder or schizophrenia. Examples of antipsychotic drugs are Haloperidol, Clozapine, Risperidone and Paliperidone.

Psychostimulants 
In the beginning, psychostimulants were only used for patients with attention deficit hyperactivity disorder. Researchers found out that they can also help patients with autism. The medication can reduce hyperactivity and inattention in people with autism. The medication can have many side-effects. Examples are Methylphenidate, Clonidine and Guanfacine.

Diet 
People with autism often have problems with their digestive organs like the stomach or gut. These problems could be inflammations, abdominal pain, gas, diarrhea or bacterial overgrowth. The reasons may be malnutrition, food intolerances or allergies. Specific food products causing these problems are left out from the diet. In many cases, products containing gluten or casein, the main protein occurring in dairy products, are excluded. In many cases vitamins, minerals as well as essential fatty acids are additionally provided. A big problem is that many autistic people cannot tell that they have pain. Because of this, many problems concerning the digestive organs are not noticed.

Therapies 
Applied Behavioral Analysis

Applied Behavior Analysis (ABA) uses research-supported data to design treatment protocols that aim to reduce problematic behavior among individuals with autism and build habits and skills to help them live more independently. ABA often includes different types of therapies including occupational therapy, speech therapy, etc.

Occupational therapy 
Therapy can be used to minimize distress caused by sensory overload. Special therapy plans are created for each autistic person. What is part of these plans depends on what the autistic person needs help with. The therapist tries to help the autistic person in many different aspects.

One part of this is sensory integration. The therapist will help the patient to make sense of different sensory inputs. For example, they may ask a child patient to play with finger paints or collect objects from a bag of dried beans.

Another part is the training of daily life activities. The therapist may help the patient to get used to things like getting dressed, eating, hygiene, shopping and financial management. These may be done one step at a time if the activity involves multiple steps, such as cooking.

Play therapy is also helpful, especially for children. It can be useful to learn about certain emotions, which can be hard for autistic people. This can also be used to help learn social conventions, such as shaking hands instead of hugging when meeting a stranger.

Therapy with animals 
Often animals are used to help autistic people. Most often dogs or horses are used. The people diagnosed with autism can care for these animals, pet them, and, in the case of the horse, even ride on them. Studies showed that the interaction between an autistic person and animals can increase communication, reduce stress, fear, and aggression, and reduce the severity of the symptoms of autism.

Music therapy 
Music therapy consists of two parts. One is an active listening part. Here, the therapist is making music himself or playing music from a record. In the other part, the autistic person can make music himself like playing an instrument or singing. Music therapy will improve different aspects of communication.

Art therapy 
Here, different materials and techniques are used to draw pictures. The aim of art therapy is to make the autistic person more flexible and relaxed and to improve communication skills, self-image and learning skills. The effects of the therapy can be long lasting and transferred to the school, work or home setting.

Related pages 
 Nonverbal learning disorder (common in people with autism spectrum disorders)
 Asperger Syndrome (a form of autism spectrum disorder)
 Imprinted Brain Theory
 Monotropism

Other websites 
 
 
 National Autistic Society http://www.autism.org.uk
 What’s the relationship between Autism and ADHD?
 About Autism from the Autistic Self Advocacy Network

Scientific studies
 Five Very Different and Major Psych Disorders Have Shared Genetics - from Science World Report (February 28, 2013) (shows genetic links between autism, ADHD, bipolar disorder, depression, and schizophrenia)
 5 Disorders Share Genetic Risk Factors, Study Finds - from The New York Times (February 28, 2013)
 Psychiatric Disorders Linked Genetically - from the Wall Street Journal (February 27, 2013)
 How to talk about autism: guidance from the community

References 

 
Pervasive developmental disorders