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Autism what causes it


What is Autism Spectrum Disorder?

Autism spectrum disorder (ASD) is a developmental disability caused by differences in the brain. Some people with ASD have a known difference, such as a genetic condition. Other causes are not yet known. Scientists believe there are multiple causes of ASD that act together to change the most common ways people develop. We still have much to learn about these causes and how they impact people with ASD.

People with ASD may behave, communicate, interact, and learn in ways that are different from most other people. There is often nothing about how they look that sets them apart from other people.  The abilities of people with ASD can vary significantly. For example, some people with ASD may have advanced conversation skills whereas others may be nonverbal. Some people with ASD need a lot of help in their daily lives; others can work and live with little to no support.

ASD begins before the age of 3 years and can last throughout a person’s life, although symptoms may improve over time. Some children show ASD symptoms within the first 12 months of life. In others, symptoms may not show up until 24 months of age or later. Some children with ASD gain new skills and meet developmental milestones until around 18 to 24 months of age, and then they stop gaining new skills or lose the skills they once had.

As children with ASD become adolescents and young adults, they may have difficulties developing and maintaining friendships, communicating with peers and adults, or understanding what behaviors are expected in school or on the job. They may come to the attention of healthcare providers because they also have conditions such as anxiety, depression, or attention-deficit/hyperactivity disorder, which occur more often in people with ASD than in people without ASD.

Signs and Symptoms

People with ASD often have problems with social communication and interaction, and restricted or repetitive behaviors or interests. People with ASD may also have different ways of learning, moving, or paying attention. It is important to note that some people without ASD might also have some of these symptoms. For people with ASD, these characteristics can make life very challenging.

Learn more about signs and symptoms of ASD »

Diagnosis

Diagnosing ASD can be difficult since there is no medical test, like a blood test, to diagnose the disorder. Doctors look at the child’s behavior and development to make a diagnosis. ASD can sometimes be detected at 18 months of age or younger. By age 2, a diagnosis by an experienced professional can be considered reliable.1 However, many children do not receive a final diagnosis until they are much older. Some people are not diagnosed until they are adolescents or adults. This delay means that people with ASD might not get the early help they need.

Learn more about screening and diagnosis of ASD »

Treatment

Current treatments for ASD seek to reduce symptoms that interfere with daily functioning and quality of life.  ASD affects each person differently, meaning that people with ASD have unique strengths and challenges and different treatment needs.2  Treatment plans usually involve multiple professionals and are catered to the individual.

Learn about treating the symptoms of ASD »

Risk Factors

There is not just one cause of ASD. There are many different factors that have been identified that may make a child more likely to have ASD, including environmental, biologic, and genetic factors.

Although we know little about specific causes, the available evidence suggests that the following may put children at greater risk for developing ASD:

  • Having a sibling with ASD
  • Having certain genetic or chromosomal conditions, such as fragile X syndrome or tuberous sclerosis
  • Experiencing complications at birth
  • Being born to older parents

CDC is currently working on one of the largest U.S. studies to date on ASD. This study called the Study to Explore Early Development (SEED), was designed to look at the risk factors and behaviors related with ASD.  CDC is now conducting a follow-up study of older children who were enrolled in SEED to determine the health, functioning, and needs of people with ASD and other developmental disabilities as they mature.

How Often ASD Occurs

CDC’s Autism and Developmental Disabilities Monitoring (ADDM) Network has been estimating the number of 8-year-old children with ASD in the United States since 2000.

ASD occurs in all racial, ethnic, and socioeconomic groups. It is more than 4 times more common among boys than among girls.

Learn more about how CDC estimates the number of children with ASD »

If You’re Concerned

As a parent, you already have what it takes to help your young child learn and grow. CDC has developed materials to help you track your child’s developmental milestones and share that progress, or any concerns, with your child’s doctor at every check-up.

Learn more about CDC milestone checklists and other parent materials »

Contact your child’s doctor if you think your child might have ASD or if you have any other concerns about the way your child plays, learns, speaks, or acts.

If you are still concerned, ask the doctor for a referral to a specialist who can do a more in-depth evaluation of your child. Specialists who can do a more in-depth evaluation and make a diagnosis include

  • Developmental pediatricians (doctors who have special training in child development and children with special needs)
  • Child neurologists (doctors who work on the brain, spine, and nerves)
  • Child psychologists or psychiatrists (doctors who know about the human mind)

At the same time, call your state’s public early childhood system to request a free evaluation, sometimes called a Child Find evaluation, to find out if your child qualifies for intervention services.  You do not need to wait for a doctor’s referral or a medical diagnosis to make this call.

Where to call for a free evaluation from the state depends on your child’s age:

  • If your child is not yet 3 years old, contact your local early intervention system.
    • You can find the right contact information for your state by calling the Early Childhood Technical Assistance Center (ECTA) at 919-962-2001.
    • Or visit the ECTA website. external icon
  • If your child is 3 years old or older, contact your local public school system.
    • Even if your child is not yet old enough for kindergarten or enrolled in a public school, call your local elementary school or board of education and ask to speak with someone who can help you have your child evaluated.
    • If you’re not sure who to contact, call the ECTA at 919-962-2001.
    • Or visit the ECTA website. external icon

Research shows that early intervention services can greatly improve a child’s development.3,4 In order to make sure your child reaches their full potential, it is very important to receive services as soon as possible.

References

  1. Lord C, Risi S, DiLavore PS, Shulman C, Thurm A, Pickles A. Autism from 2 to 9 years of age. Arch Gen Psychiatry. 2006 Jun;63(6):694-701.
  2. Hyman, S.L., Levy, S.E., Myers, S.M., & AAP Council on Children with Disabilities, Section on developmental and behavioral pediatrics. (2020). Identification, evaluation, and management of children with autism spectrum disorder. Pediatrics, 145(1), e20193447.
  3. Handleman, J.S., Harris, S., eds. Preschool Education Programs for Children with Autism (2nd ed). Austin, TX: Pro-Ed. 2000.
  4. National Research Council. Educating Children with Autism. Washington, DC: National Academy Press, 2001.
  • Child Development
  • Developmental Disabilities
  • “Learn the Signs. Act Early.” Campaign
  • CDC’s National Center on Birth Defects and Developmental Disabilities

What Causes Autism? | Autism Speaks

The information below is not meant to diagnose or treat. It should not take the place of consultation with a qualified healthcare professional.

A common question after an autism diagnosis is what is the cause of autism.  

We know that there’s no one cause of autism. Research suggests that autism develops from a combination of genetic and nongenetic, or environmental, influences.

These influences appear to increase the risk that a child will develop autism. However, it’s important to keep in mind that increased risk is not the same as cause. For example, some gene changes associated with autism can also be found in people who don’t have the disorder. Similarly, not everyone exposed to an environmental risk factor for autism will develop the disorder. In fact, most will not.

Autism’s genetic risk factors

Research tells us that autism tends to run in families. Changes in certain genes increase the risk that a child will develop autism. If a parent carries one or more of these gene changes, they may get passed to a child (even if the parent does not have autism). Other times, these genetic changes arise spontaneously in an early embryo or the sperm and/or egg that combine to create the embryo. Again, the majority of these gene changes do not cause autism by themselves. They simply increase risk for the disorder

Autism’s environmental risk factors

Research also shows that certain environmental influences may further increase – or reduce – autism risk in people who are genetically predisposed to the disorder. Importantly, the increase or decrease in risk appears to be small for any one of these risk factors:

Increased risk
  • Advanced parent age (either parent)
  • Pregnancy and birth complications (e.g. extreme prematurity [before 26 weeks], low birth weight, multiple pregnancies [twin, triplet, etc.])
  • Pregnancies spaced less than one year apart
Decreased risk
  • Prenatal vitamins containing folic acid, before and at conception and through pregnancy 
No effect on risk

  • Vaccines. Each family has a unique experience with an autism diagnosis, and for some it corresponds with the timing of their child’s vaccinations. At the same time, scientists have conducted extensive research over the last two decades to determine whether there is any link between childhood vaccinations and autism. The results of this research is clear: Vaccines do not cause autism. The American Academy of Pediatrics has compiled a comprehensive list of this research.

Differences in brain biology

How do these genetic and nongenetic influences give rise to autism? Most appear to affect crucial aspects of early brain development. Some appear to affect how brain nerve cells, or neurons, communicate with each other. Others appear to affect how entire regions of the brain communicate with each other. Research continues to explore these differences with an eye to developing treatments and supports that can improve quality of life.

causes, symptoms, diagnosis and treatment

IMPORTANT!

The information in this section should not be used for self-diagnosis or self-treatment. In case of pain or other exacerbation of the disease, only the attending physician should prescribe diagnostic tests. For diagnosis and proper treatment, you should contact your doctor.
For a correct assessment of the results of your analyzes in dynamics, it is preferable to do studies in the same laboratory, since different laboratories may use different research methods and units of measurement to perform the same analyzes.

Definition

Autism, more specifically Autism Spectrum Disorders (ASD), is a group of mental disorders characterized by impairments in social interaction and communication – the process of communicating and passing information to other people. Autism is characterized by limited, stereotyped, repetitive behavior. In different patients, disorders are expressed to varying degrees, while they may or may not be accompanied by impaired speech and intellectual development.

The first signs of the disease are noted already in infancy or early childhood, anomalies in social functioning and behavior persist throughout life.


Causes of autism

The causes of autism spectrum disorders are not fully understood, but it is believed that genetic factors play a leading role. It is known that the risk of having a child with ASD increases with the age of the parents.

Possible relationship between the onset of ASD in a child and the course of pregnancy: prematurity of the fetus, the use of valproic acid preparations by the mother during pregnancy to treat epilepsy, manic-depressive psychosis, migraine, as well as gestational diabetes in the mother (diabetes mellitus that develops during pregnancy ). It is unlikely that any of these factors is of decisive importance in the development of ASD, but may be realized in interaction with a genetic predisposition.

Autism is more commonly diagnosed in boys, with a sex ratio of approximately 3:1.

Since the mid-1990s, there have been concerns about the possible association of vaccination with the onset of ASD. Current epidemiological data indicate no such association. Moreover, there is no evidence of an association between the use of vaccines and the risk of developing ASD, even when vaccinating children at risk - brothers and sisters of children with ASD. It has been proven that the preservative thiomersal and aluminum adjuvant contained in inactivated vaccines do not increase the likelihood of ASD in vaccinated children. According to many international studies, changes in the vaccination schedule, the withdrawal of any vaccines and their components did not affect the incidence of ASD.

Disease classification

Depending on the number of symptoms and their severity, there are three main types of ASD: childhood autism, atypical autism, and Asperger's syndrome.

Asperger's syndrome is the mildest form of ASD - intelligence does not suffer, changes can be regarded as personality traits and do not interfere with professional development and social adaptation of a person.

There is a division of the RAS depending on the presence or absence of intellectual disabilities and the ability of a person to use spoken or written language as a means to express needs or desires.

Symptoms of autism

The main manifestations of ASD are disorders in social interaction, communication (anomalies in communication) and limited, stereotyped, repetitive behavior. In addition, patients often have other non-specific problems: various phobias (fears), sleep and nutrition disorders, aggression and auto-aggression (aggression directed at oneself). Contrary to popular belief, most autism spectrum disorders are not associated with a high level of intelligence, although some patients may have extraordinary abilities in some area of ​​knowledge.

Let us dwell in more detail on the description of the main manifestations of the disease.

Disorders of social interaction and social communication . Parents pay attention to the fact that the child rarely uses eye contact, gestures, facial expressions and posture to regulate social interaction, he has reduced interest in interacting with peers and adults. The child may not speak or start speaking with a strong delay, and if he does, he does not start a conversation, does not ask questions, communicates exclusively on topics of interest to him; can repeat the same words and phrases over and over. The baby has no desire to walk in his arms, he does not always distinguish parents from other people. Such children do not look at the interlocutor, may not respond to the speech addressed to them, to requests, do not respond to the name, they do not enter into or reluctantly enter into a dialogue, do not smile in response.

Often, a child with autism can observe unusual behavior, for example, violation of bodily boundaries, lack of embarrassment or excessive anxiety when interacting with new people, monotonous scenarios in communication.

After the age of 7 years, some children with ASD remain speechless or have a minimal set of words. Other children, starting to communicate, cannot build long-term friendships and take into account social rules. The problem of many older children and adults with autism is the inability to understand and feel the state of other people, their mood.

People with ASD are characterized by naivete, innocence, they do not understand irony and humor well, they experience difficulties in maintaining a dialogue and understanding the rules of behavior.

Many patients with ASD retain excessive or, conversely, absent gesticulation, unstable or excessive eye contact.

Stereotyped, repetitive behavior, limited interests and hobbies . With the exception of Asperger's syndrome, most patients present with varying degrees of intellectual decline. Children with ASD are characterized by peculiar play activities, for example, a child may use toys in an unusual way: scatter, lick or perform other repetitive manipulations. Already in early childhood, selective interests often appear - for example, it can be the study of moving objects, a passion for narrow topics (interest in the alphabet, numbers, names and individual characteristics of objects). Such children experience pronounced difficulties when it is necessary to switch attention.

With age, the set of symptoms may change in content and severity. Many older children and adults are characterized by inflexibility of thinking, manifested by a lack of response to changing environmental conditions, the difficulty of assimilating and using new information, practical skills, and an excessive tendency to detail.

Autism Diagnostics

When collecting complaints and examining, the doctor draws attention to the characteristics of the patient's behavior, assesses the current psychiatric status and level of development.

To clarify the diagnosis and improve the accuracy of clinical diagnostics, additional standardized methods related to the "gold standard" are used: ADOS-II and ADI-R.

ADOS-II is a test performed by a child or adult psychiatrist or clinical psychologist. It consists in observing the patient performing certain tasks in a playful way. Depending on age, ability to speak and play, the doctor chooses one or another module - a type of testing. The modules differ in the complexity of the proposed games, activities and the presence of speech tasks. The 1st module is used for children speaking in separate words. 2nd - for children using sentences of several words. 3rd - for freely communicating children. 4th - for freely communicating teenagers and adults. With the help of a certain set of toys and items, the specialist creates various game situations. He observes the performance of the work, evaluating facial expressions, words, ways of solving the proposed tasks. The tasks last about an hour, after which the specialist processes the test results and draws up a conclusion. Usually, the test is recorded on video, which helps to make a more accurate diagnosis and provides an opportunity for other specialists to assess the child's condition.

ADOS-II is not the only criterion for making a diagnosis. As an additional test to collect more data, the ADI-R screening can be used.

ADI-R - an interview with about 100 questions conducted by a psychologist or psychiatrist; but not with the patient, but with his parents or other close people. The questions are aimed at assessing:

  • the quality of social contact;
  • quality of communication and speech features,
  • behavior patterns (repetitive, limited or stereotyped actions).

Genetic testing may be recommended in children and adolescents with an established diagnosis to clarify the immediate cause of ASD. It is compiled according to an individual plan with the involvement of geneticists or other specialists.

Instrumental methods of examination are of secondary importance, not leading in the diagnosis of ASD. Electroencephalography (EEG), computed tomography (CT) of the brain, and magnetic resonance imaging (MRI) of the brain are not recommended for all children and adolescents with or suspected ASD. On the one hand, this is due to the fact that the examination may be difficult due to ASD-specific violations of the patient's communication and behavioral skills. On the other hand, these studies cannot confirm or refute the diagnosis of autism spectrum disorder, but may be indicated for diagnosis and treatment in case of suspected presence of other disorders, for example, epilepsy, brain tumor.

Which doctors to contact

Autism can be suspected pediatrician. Confirms the diagnosis, prescribes therapy and observes children, and then an adult psychiatrist, neuropathologist, psychologist.

Autism treatment

There is currently no direct treatment for ASD. Prescribed medications, for example, from the group of antidepressants, can help in solving various non-specific problems - sleep and nutrition disorders, increased irritability, attacks of aggression directed at oneself or others. The main treatments for ASD are predominantly non-pharmacological in nature. They include educational and psychological assistance aimed at the socialization of a person with ASD - the earlier assistance is started, the better the prognosis for the development of the child.

There are many methods of treatment and care for patients with ASD that have no proven effectiveness: gluten-free and casein-free diets, brain micropolarization, the Tomatis method, bioacoustic correction, art therapy, as well as hippotherapy, dolphin therapy and many others. If parents insist on using these methods, it is important to understand that they should not be used as a substitute for the main treatment program.

Nootropic and peptide drugs are often used in the treatment of patients with ASD. Currently, there is no convincing evidence of their ability to influence the development of cognitive and speech skills. However, they can increase motor activity, cause disinhibition and sleep disorders.

Complications of the disease

With autism, various damages are possible that the patient inflicts on himself and others.

Due to impaired cognitive functions, speech, difficulties in interacting with others, patients with ASD, with the exception of patients with Asperger's syndrome, in most cases cannot live independently, study and work.

Diagnosis and treatment of other diseases are difficult due to the high pain threshold and behavioral characteristics of those suffering from ASD.

Prevention of autism

There are currently no specific measures to prevent ASD. However, early diagnosis is a necessary condition for organizing early comprehensive care for a child, which can improve the prognosis.

Sources:

  1. Clinical guidelines. Autism Spectrum Disorders. Clinical recommendation developer Association of Psychiatrists and Psychologists for evidence-based practice Approved by the Scientific and Practical Council of the Ministry of Health of the Russian Federation, 2020. - p. 52.
  2. Bozhkova E.D., Balandina O.V., Konovalov A.A. Autism Spectrum Disorders: Current State of the Problem (Review). Modern technologies in medicine. T. 12, No. 2, 2020. S. 111-120.

IMPORTANT!

The information in this section should not be used for self-diagnosis or self-treatment. In case of pain or other exacerbation of the disease, only the attending physician should prescribe diagnostic tests. For diagnosis and proper treatment, you should contact your doctor.
For a correct assessment of the results of your analyzes over time, it is preferable to do studies in the same laboratory, since different laboratories may use different research methods and units of measurement to perform the same analyzes.


Autism: What is autism and how to recognize it?, Causes, Diagnosis

What is autism and how to recognize it?

Childhood autism is a serious disorder of the development of the nervous system, which affects, according to various sources, 1 out of 160 children (according to some estimates, 1 out of 50). Autism is manifested, first of all, by violations of communication and social functions: problems with speech, understanding and following instructions, unwillingness to communicate with others, detachment and the desire for loneliness. The second obligatory symptom of autism is the monotony or stereotyping of behavior. The child may have repetitive movements such as arm flapping, jumping in place, running in circles, clapping hands, and limited or repetitive interests or habits. Often such children are overly interested, for example, in cars, trains, wheels, less often in various symbols, numbers, flags, signs.

Signs of autism appear before the age of 3 years.

Today, the term "autism" is gradually replacing the more accurate diagnosis of "autism spectrum disorder". The introduction of this term emphasizes that the same diagnosis can be made to children with completely different severity of symptoms, intelligence level, and also the cause of the disease. That is, one cannot reject the diagnosis of autism on the basis that the child is “not like” other children with a similar disorder or does not have certain manifestations.

Unfortunately, most parents seek help when their child is 2-3 years old or later. This is usually the age when parents first notice that the child is developing differently than his peers. “Doesn’t speak”, “only speaks single words”, “is not interested in other children and toys”, “does not comply with my requests”, “does not respond to his name” - an incomplete list of typical complaints that mom and dad go to the doctor such children. What prevents you from paying attention to disturbing symptoms earlier? Many people think that problems with speech, communication, or behavior are temporary and will go away on their own. Often, under the influence of relatives, soothing formulations appear: “he will still speak out”, “still a little”, “boys are lazier and start talking later”.

Causes

It should be said right away that there is no unequivocal opinion on the nature of the occurrence of this disease among scientists today. For a long period, disturbances in the structure of genes and their direct effect on synoptic connections in the cerebral cortex were considered the main cause. However, in recent years, many scientists have expressed the opinion about a rare mutation that occurs during the intrauterine development of the fetus.

There is also an opinion about the effect of the social factor, namely the conditions surrounding the baby in the first years of his life. In addition, there are a number of scientifically unconfirmed versions, among which there is vaccination of newborns. The prevalence of the disease is quite significant, on average, childhood autism occurs in six people out of a thousand, while the ratio of affected boys to girls is 4:1.

Symptoms

The main manifestations of this disease are
  • limited communication and contact with the outside world;
  • narrowly focused interests and monotonous, often repetitive, actions;
  • mental retardation;
  • a significant delay in the development of speech in a child;
  • when talking, it is noticeable that the child is experiencing significant difficulties, he is not able to be the first to start a conversation and maintain it with others;
  • the patient often repeats learned phrases he heard earlier;
  • the presence of such concepts as humor, veiled communication, hidden meaning is completely absent in the patient;
  • there is a violation of sensory perception, the slightest touch to the patient causes him a state of discomfort.

Symptoms of autism in early childhood may also be reluctance to play with toys or focus on one of its parts. A child may put forward a number of unreasonable demands, namely, to move along a strictly defined route, to carry out certain actions in a strictly established order. Such children do not perceive parental affection well, do not like collective and sound games, the child ignores the appeal to him, responding only to individual sounds.

Autism in adults is manifested by a peculiar passion for certain topics, characteristic movements, patterned thinking. A third of the number of sick people can achieve some progress in education and career, but at the same time they will constantly experience significant difficulties in communication. The intelligence of adults cannot be above average, some have the ability to improve themselves, an autistic person can memorize poems and play musical instruments.

Diagnosis

Early diagnosis provides an opportunity to help develop a child's potential. For this reason, the development of autism, the symptoms of which can be determined already in the first years of a child's life, will depend on timely diagnosis and qualified treatment.

To determine the stage of development of the disease, there are many different programs, including tests and surveys that measure the level of intelligence of the child and compliance with the required stage of development. The development of the muscular system of the body is also examined, which, with a disease, can significantly lag behind in development.

Laboratory tests are at the discretion of the physician and may include
  • magnetic resonance imaging if changes in brain structure are detected;
  • electroencephalography - in the presence of seizures characteristic of this disease;
  • chromosome analysis - in case of aggravated heredity.

Parents may be concerned about situations when a child at one year old does not produce sounds characteristic of his age, does not point to an object upon request, at a year and a half a child does not pronounce words, and at two years old - the simplest phrases. Timely diagnosis will allow you to apply adequate treatment and help the child develop fully.

Treatment

The main problem in the treatment of this disease is that at the moment there are no single methods that can ensure complete recovery from this pathology. In addition, there are still disputes about whether autism is considered a disease or a special human condition?

In any case, the child needs to adapt to life in society, and for this he needs to be given adequate assistance. Not all children are destined to become full-fledged members of society, but many of them, having reached adulthood, can lead an independent life.

Children attending specialized summer camps and pedagogical centers specializing in the treatment of this pathology have a positive effect on the development of the child. The principle consists in the intensive passage of various trainings, both individual and group.

Kinesitherapy, music and painting therapy enjoy great success.

Learn more