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AUTISM RESEARCH AT THE NICHD AUTISM OVERVIEW 

What is autism? 

Autism is a complex neurobiological disorder of 

development that lasts throughout a person’s life. 

It is sometimes called a developmental disability 

because it usually starts before age three, in the 

developmental period, 

and because it causes Check the Glossary on delays or problems in Pages 14-15 to learn

many different skills how to say the bolded 

words and what that arise from infancy they mean. to adulthood. 

The main signs and symptoms of autism 

involve1 language, social behavior, and behaviors 

concerning objects and routines: 

● Communication—both verbal (spoken) and 

non-verbal (unspoken, such as pointing, eye 

contact, or smiling) 

● Social interactions—such as sharing emotions, 

understanding how others think and feel 

(sometimes called empathy), and holding a 

conversation, as well as the amount of time a 

person spends interacting with others 

● Routines or repetitive behaviors—often called 

stereotyped behaviors, such as repeating 

words or actions, obsessively following 

routines or schedules, playing with toys or 

objects in repetitive and sometimes 

inappropriate ways, or having very specific and 

inflexible ways of arranging items 

People with autism might have problems talking 

with you, or they might not look you in the eye 

when you talk to them. They may have to line 

up their pencils before they can pay attention, or 

they may say the same sentence again and again 

to calm themselves down. They may flap their 

arms to tell you they are happy, or they might 

hurt themselves to tell you they are not. Some 

people with autism never learn how to talk. 

These behaviors not only make life challenging 

for people who have autism, but also take a toll 

on their families, their health care providers, their 

teachers, and anyone who comes in contact 

with them. 

Because different people with autism can have 

very different features or symptoms, health care 

providers think of autism as a “spectrum” 

disorder—a group of disorders with a range of 

similar features. Based on their specific strengths 

and weaknesses, people with autism spectrum 

disorders (ASDs) may have mild symptoms or 

more serious symptoms, but they all have an 

ASD. This fact sheet uses the terms “ASD” and 

“autism” to mean the same thing. 

What conditions are in the 

ASD category? 

Currently, the ASD category includes: 

● Autistic disorder (also called “classic” autism) 

● Asperger syndrome 

● Pervasive Developmental Disorder Not 

Otherwise Specified (or atypical autism) 

In some cases, health care providers use a 

broader term—pervasive developmental disorders 

(PDD)—to describe autism. The PDD category 

includes the ASDs mentioned above and: 

Childhood disintegrative disorder, and Rett 

syndrome. 

Depending on specific symptoms, a person with 

autism may fall into the ASD or the PDD 

category. Sometimes, the terms “ASD” and 

“PDD” are used to mean the same thing because 

autism is in both categories. 

What causes autism? 

Scientists don’t know exactly what causes autism 

at this time. 

Much evidence supports the idea that genetic 

factors—that is, genes, their function, and their 

interactions—are one of the main underlying 

causes of ASDs. But, researchers aren’t looking 

for just one gene. Current evidence suggests 

that as many as 10 or more genes on different 

chromosomes may be involved in autism, to 

different degrees. 

Some genes may place a person at greater risk 

for autism, called susceptibility. Other genes 

may cause specific symptoms or determine how 

severe those symptoms are. Or, genes with 

changes or mutations might add to the 

symptoms of autism because the genes or gene 

products aren’t working properly. 

Research has also shown that environmental 

factors, such as viruses, may also play a role in 

causing autism. 

While some researchers are examining genes and 

environmental factors, other researchers are 

looking at possible neurological, infectious, 

metabolic, and immunologic factors that may be 

involved in autism. 

Because the disorder is so complex, and because 

no two people with autism are exactly alike, 

autism is probably the result of many causes. 

Is there a link between autism 

and vaccines? 

To date, there is no conclusive scientific evidence 

that any part of a vaccine or any combination of 

vaccines causes autism, even though researchers 

have carried out many studies to answer this 

important question. There is also no proof that 

any material used to make or preserve vaccines 

plays a role in causing autism. 

Although there have been reports of studies that 

relate vaccines to autism, the findings have not 

held up under further investigation. Researchers 

have been unable to replicate the studies that 

reportedly found a link between autism and 

vaccines. 

There is a great deal of research and discussion 

on the topic of vaccines and autism—too much 

to cover here. The U.S. Centers for Disease 

Control and Prevention (CDC) conducts and 

supports most of the federal epidemiological 

studies that seek to answer questions about 

vaccines and autism. 

Currently, the CDC provides the most accurate 

and up-to-date information about research on 

autism and vaccine research, both supported by 

the federal government and funded 

independently. For more information, visit 

http://www.cdc.gov/nip/vacsafe/concerns/autism/ 

default.htm. 

2 3 
AUTISM RESEARCH AT THE NICHD AUTISM OVERVIEW 

How many people 

have autism? 

Currently, researchers don’t know the exact 

number of people with an ASD in the United 

States. 

Researchers use different ways to determine 

prevalence that often give different results. 

Some estimates of prevalence rely on previously 

published studies. Researchers review all the 

published data on a topic and take the averages 

of these calculations to determine prevalence. 

Independent researchers3 recently conducted two 

such reviews. Based on these studies, the best 

conservative estimate4 of the prevalence of 

ASDs in the United States is that one child in 

1,000 children has an ASD. 

Is autism more common now than 

it was in the past? 

Researchers are not certain whether autism is 

more prevalent now than in the past for a 

number of reasons. Although more cases of 

autism are being identified, it is not clear why. 

Some of the increase may result from better 

education about the symptoms of autism or 

from more accurate diagnoses of autism. 

The new definition of autism as a spectrum 

disorder means that even people with mild 

symptoms can be classified as having an ASD, 

which could also account for the increase in 

identified cases. As research moves forward 

using the current definition of ASDs, more 

definite numbers may be available to answer this 

question. 

Is autism more common in
 

certain groups of people?
 

Current figures show that autism occurs in all 

racial, ethnic, and social groups equally, with 

individuals in one group no more or less likely to 

have ASDs than those in other groups. Three 

groups are at higher-than-normal risk for ASDs, 

including: 

● Boys. Statistics show that boys are three to 

four times more likely5 to be affected by 

autism than are girls. 

● Siblings of those with ASDs. Among families 

that have one child with an ASD, recurrence of 

ASD in another sibling is between6 2 percent 

and 8 percent, a figure much higher than in the 

general population. 

● People with certain other developmental disorders. 

For certain disorders, including Fragile X 

syndrome, mental retardation, and tuberous 

sclerosis, autism is common in addition to the 

primary symptoms of the disorder. 

When do people usually show

signs of autism? 

A number of the behavioral symptoms7 of 

autism are observable by 18 months of age, 

including: problems with eye contact, not 

responding to one’s name, joint attention 

problems, underdeveloped skills in pretend play 

and imitation, and problems with non-verbal 

communication and language. 

Some studies also note that, although more 

subtle, some signs of autism are detectable at 

eight months8 of age. 

In general, the average age of autism diagnosis is 

currently three years old. In many cases, a delay 

in the child’s starting to speak around age two 

brings problems to parents’ attention, even 

though other, less noticeable signs may be 

present at an earlier age.9 

Studies10 also show that a subgroup of children 

with ASDs experiences a “regression,” meaning 

they stop using the language, play, or social skills 

they had already learned. This regression usually 

happens between the first and second birthdays. 

Researchers are still learning about the features 

of regression in ASDs, and whether the features 

differ from those shown by individuals who 

show signs of autism in early life. 

What are some of the 

possible signs of autism? 

Parents, caregivers, family members, teachers, 

and others who spend a lot of time with 

children can look for “red flags.” Some may 

mean a delay in one or more areas of 

development, while others are more typical of 

ASDs. A list of red flags appears to the right. 

Possible Red Flags for Autism11 

● The child does not respond to his/her name. 

● The child cannot explain what he/she wants. 

●	 The child’s language skills are slow to develop or speech is 

delayed. 

● The child doesn’t follow directions. 

● At times, the child seems to be deaf. 

● The child seems to hear sometimes, but not other times. 

● The child doesn’t point or wave “bye-bye.” 

●	 The child used to say a few words or babble, but now 

he/she doesn’t. 

● The child throws intense or violent tantrums. 

● The child has odd movement patterns. 

● The child is overly active, uncooperative, or resistant. 

● The child doesn’t know how to play with toys. 

● The child doesn’t smile when smiled at. 

● The child has poor eye contact. 

●	 The child gets “stuck” doing the same things over and over 

and can’t move on to other things. 

● The child seems to prefer to play alone. 

● The child gets things for him/herself only. 

● The child is very independent for his/her age. 

● The child does things “early” compared to other children. 

● The child seems to be in his/her “own world.” 

● The child seems to tune people out. 

● The child is not interested in other children. 

● The child walks on his/her toes. 

●	 The child shows unusual attachments to toys, objects, or 

schedules (i.e., always holding a string or having to put 

socks on before pants). 

●	 Child spends a lot of time lining things up or putting things 

in a certain order. 

4	 5
 
AUTISM RESEARCH AT THE NICHD AUTISM OVERVIEW 

In addition, your child’s health care provider will 

send your child for an evaluation if you report 

any of the behaviors listed below; such an 

evaluation would consider ASDs, among other 

possible causes.

12 

If the child... 

● Does not babble or coo by 12 months of age 

● Does not gesture (point, wave, grasp, etc.) by 

12 months of age 

● Does not say single words by 16 months 

of age 

● Does not say two-word phrases on his or her 

own (rather than just repeating what someone 

says to him or her) by 24 months of age 

● Has ANY loss of ANY language or social 

skill at ANY age 

What should I do if I think my

child has a developmental

problem or autism? 

Tell your child’s health care provider immediately 

if you think something is wrong. 

According to the American Academy of Pediatrics 

(AAP)13, “Pediatricians should listen carefully to 

parents discussing their child’s development. 

[Parents] are reliable sources of information and 

their concerns should be valued and addresses 

immediately.” 

Your child’s health care provider will note your 

comments and concerns, will ask some other 

questions, and will determine the best plan of 

action. In some cases, the health care provider 

will ask you to complete a questionnaire about 

your child to get more specific information 

about symptoms. To rule out certain conditions, 

the health care provider will also test your child’s 

hearing and check your child’s lead level before 

deciding on a course of action. 

If red flags are present, and if the lead and 

hearing tests show no problems, your child’s 

health care provider may refer you to a specialist 

in child development or another specialized 

health care provider. The specialist will conduct 

a number of tests to determine whether or not 

your child has autism or an ASD. 

What if I don’t notice any symptoms? 

If you don’t report any of these signs, your 

child’s health care provider will continue to check 

for problems at every well-baby and well-child 

visit.14 If your child’s health care provider does 

not routinely check your child with such tests, 

you should ask that he or she do so. 

In this developmental screening, the provider 

asks questions related to normal development 

that can help measure your child’s specific 

progress. Typically, these questions are similar to 

the red flags listed earlier. Based on your 

answers, the health care provider may send your 

child for further evaluation. 

The AAP recommends15 that health care 

providers ask questions about different aspects 

of development. These questions include (but 

are not limited to) those listed here. 

Does your child...15
 

●	 Not speak as well as other children 

his/her age? 

● Have poor eye contact? 

● Act as if he/she is in his/her own world? 

● Seem to “tune out” others? 

● Not smile when smiled at? 

●	 Seem unable to tell you what he/she wants, 

and so takes your hand and leads you to what 

he/she wants, or gets it him/herself? 

● Have trouble following simple directions? 

● Not play with toys in a usual way? 

●	 Not bring things to you to “show” you 

something? 

●	 Not point to interesting things or direct your 

attention to items of interest? 

●	 Have unusually long or severe temper 

tantrums? 

●	 Show an unusual attachment to objects, 

especially “hard” ones, such as a flashlight or 

key chain, instead of “soft” ones, such as a 

blanket or stuffed animal? 

● Prefer to play alone? 

●	 Not pretend or play “make believe” (if the 

child is older than age two)? 

Is there a cure for autism?
 

To date, there is no cure for autism, but 

sometimes, children with ASDs make so much 

progress that they no longer show the full 

syndrome of autism when they are older. 

Research16 shows that early diagnosis and 

interventions delivered early in life, such as in 

the preschool period, are more likely to result in 

major positive effects on later skills and 

symptoms. The sooner a child begins to get 

help, the more opportunity for learning. Because 

a young child’s brain is still forming, early 

intervention gives children the best start possible 

and the best chance of developing their full 

potential. Even so, no matter when a person is 

diagnosed with autism, it’s never too late to 

benefit from treatment. People of all ages with 

ASDs at all levels of ability generally respond 

positively to well designed interventions. 

Public Law 108-77: Individuals with Disabilities 

Education Improvement Act17(2004) and Public 

Law 105-17: Individuals with Disabilities Act, or 

IDEA18 (1997) require your child’s primary care 

provider to refer you and your family to an early 

intervention service. Every state operates an 

early intervention program for children from 

birth to age three; children with autism should 

qualify for these services. Early intervention 

programs typically include behavioral methods, 

early developmental education, communication 

skills, occupational and physical therapy, and 

structured social play. 

6 7 
AUTISM RESEARCH AT THE NICHD AUTISM OVERVIEW 

What are the treatments 

for autism? 

Currently there is no definitive, single treatment 

for ASDs. However, there are a variety of ways 

to help minimize the symptoms and maximize 

learning. Persons with an ASD have the best 

chance of using all of their individual capabilities 

and skills if they receive appropriate behavioral 

and other therapies, education, and medication. 

In some cases, these treatments can help people 

with autism function at near-normal levels. 

Some possible treatments for autism are 

explained below. If you have a question about 

treatment, you should talk to a health care 

provider who specializes in caring for people 

with autism. 

Behavioral therapy and other 

therapeutic options 

In general, behavior management therapy 

works to reinforce wanted behaviors and reduce 

unwanted behaviors. At the same time, these 

methods also suggest what caregivers should do 

before or between episodes of problem 

behaviors, and what to do during or after these 

episodes. Behavioral therapy is often based on 

Applied Behavior Analysis (ABA). Different 

applications of ABA commonly used for people 

with autism include: Positive Behavioral 

Interventions and Support (PBS), Pivotal 

Response Training (PRT), Incidental Teaching, 

Milieu Therapy, Verbal Behavior, and Discrete 

Trial Teaching (DTT), among others. 

Keep in mind that other therapies, beyond ABA, 

may also be effective for persons with autism. 

Talk to your health care provider about the best 

options for your child. 

A variety of health care providers can also help 

individuals with ASDs and their families to work 

through different situations. 

●	 Speech-language therapists can help people 

autism improve their general ability to 

communicate and interact with others 

effectively, as well as develop their speech and 

language skills. These therapists may teach 

non-verbal ways of communicating and may 

improve social skills that involve 

communicating with others. They may also 

help people to better use words and sentences, 

and to improve rate and rhythm of speech and 

conversation. 

●	 Occupational therapists can help people with 

autism find ways to adjust tasks and conditions 

that match their needs and abilities. Such help 

may include finding a specially designed 

computer mouse and keyboard to ease 

communication, or identifying skills that build 

on a person’s interests and individual 

capabilities. Occupational therapists may also 

do many of the same types of activities as 

physical therapists do (see below). 

●	 Physical therapists design activities and 

exercises to build motor control and to 

improve posture and balance. For example, 

they can help a child who avoids body contact 

to participate in activities and games with other 

children. 

Special services are often available to preschool 

and school-aged children, as well as to teens, 

through the local public school system. In many 

cases, services provided by specialists in the 

school setting are free. More intense and 

individualized help is available through private 

clinics, but the family usually has to pay for 

private services, although some health insurance 

plans may help cover the cost. 

Educational and/or 

school-based options 

Children with ASDs are guaranteed free, 

appropriate public education under federal laws. 

Public Law 108-77: Individuals with Disabilities 

Education Improvement Act17 (2004) and Public 

Law 105-17: The Individuals with Disabilities 

Education Act—IDEA18 (1997) make it possible 

for children with disabilities to get free 

educational services and educational devices to 

help them learn as much as they can. Each child 

is entitled to these services from age three 

through high school, or until age 21, whichever 

comes first. 

The laws state that children must be taught in 

the least restrictive environment, appropriate for 

that individual child. This statement does not 

mean that each child must be placed in a regular 

classroom. Instead, the laws mean that the 

teaching environment should be designed to 

meet a child’s learning needs, while minimizing 

restrictions on the child’s access to typical 

learning experiences and interactions. Educating 

persons with ASDs often includes a combination 

of one-to-one, small group, and regular 

classroom instruction. 

To qualify for special education services, the 

child must meet specific criteria as outlined by 

federal and state guidelines. You can contact a 

local school principal or special education 

coordinator to learn how to have your child 

assessed to see if he or she qualifies for services 

under these laws. 

If your child qualifies for special services, a team 

of people, including you and your family, 

caregivers, teachers, school psychologists, and 

other child development specialists, will work 

together to design an Individualized 

Educational Plan (IEP)19 for your child. An 

IEP includes specific academic, communication, 

motor, learning, functional, and socialization 

goals for a child based on his or her educational 

needs. The team also decides how best to carry 

out the IEP, such as determining any devices or 

special assistance the child needs, and identifying 

the developmental specialists who will work 

with the child. 

The special services team should evaluate and 

re-evaluate your child on a regular basis to see 

how your child is doing and whether any 

changes are needed in his or her plan. 

A number of parents’ organizations, both 

national and local, provide information on 

therapeutic and educational services and how to 

get these services for a child. Visit 

http://www.nlm.nih.gov/medlineplus/autism.html 

for a listing of these organizations, or check the 

local phone book. 

8	 9
 
AUTISM RESEARCH AT THE NICHD AUTISM OVERVIEW 

Medication options 

Currently, there is no medication that can cure 

ASDs or all of the associated symptoms. 

Further, the Food and Drug Administration 

(FDA) has not approved any drugs specifically 

for the treatment of autism or its causes. But, in 

many cases, medication can treat some of the 

symptoms associated with ASDs. 

Please note that the NICHD does not endorse or 

support the use of any of these medications for 

treating symptoms of ASDs, or for other conditions 

for which the medications are not FDA approved. 

Medication can improve the behavior of a 

person with autism. Health care providers often 

use medications to deal with a specific behavior, 

such as reducing self-injurious behavior. With 

the symptom minimized, the person with autism 

can focus on other things, including learning and 

communication. Some of these medications 

have serious risks involved with their use; others 

may make symptoms worse at first or may take 

several weeks to become effective. 

Not every medication helps every person with 

symptoms of autism. Health care providers 

usually prescribe medications on a trial basis, to 

see if it helps. Your child’s health care provider 

may have to try different dosages or different 

combinations of medications to find the most 

effective plan. Families, caregivers, and health 

care providers need to work together to make 

sure that medications are working and that the 

overall medication plan is safe. 

Medications used to treat the symptoms of 

autism20 may include (but are not limited to): 

● Selective serotonin re-uptake inhibitors (SSRIs) 

are a group of antidepressants that treat 

problems, such as obsessive-compulsive 

behaviors and anxiety, resulting from an 

imbalance in one of the body’s chemical 

systems that are sometimes present in autism. 

These medications may: reduce the frequency 

and intensity of repetitive behaviors; decrease 

irritability, tantrums, and aggressive behavior; 

and improve eye contact. 

● Tricyclics are another type of antidepressant 

used to treat depression and obsessivecompulsive behaviors. Although these drugs 

tend to cause more side effects than the SSRIs, 

sometimes they are more effective for certain 

people. 

● Psychoactive or anti-psychotic medications affect 

the brain of the person taking them. Use of 

this group of drugs is the most widely studied 

treatment for autism. In some people with 

ASDs, these drugs may decrease hyperactivity, 

reduce stereotyped behaviors, and minimize 

withdrawal and aggression. 

● Stimulants may be useful in increasing focus 

and decreasing hyperactivity in people with 

autism, particularly in higher-functioning 

individuals. Because of the risk of side effects, 

health care providers should monitor those 

using these drugs carefully and often. 

● Anti-anxiety drugs can help relieve anxiousness 

and panic disorders associated with autism. 

What is secretin and is it an effective 

treatment for autism? 

Secretin is a hormone produced by the small 

intestine that helps in digestion. Currently, the 

FDA approves a single dose of secretin only for 

use in diagnosing digestive problems. 

In the 1990s, news reports described a few 

persons with autism whose behavior improved 

after getting secretin during a diagnostic test. 

However, a series21 of clinical trials funded by 

the NICHD and conducted through the 

Network on the Neurobiology and Genetics of 

Autism: Collaborative Programs of Excellence in 

Autism (CPEAs) found no difference in 

improvement between those taking secretin and 

those taking placebo. In fact, of the five casecontrolled clinical trials published on secretin, 

not one showed secretin as any better than 

placebo, no matter what the dosage or frequency. 

For this reason, secretin is not recommended as 

a treatment for ASDs. 

Are there other disorders 

associated with ASDs? 

In about 5 percent22 of autism cases, another 

disorder is also present. Studying this kind of 

co-occurrence helps researchers who are trying 

to pinpoint the genes involved in autism. Similar 

disorders or disorders with similar symptoms 

may have similar genetic origins. In cases of one 

disorder commonly occurring with another, it 

could be that one is actually a risk factor for the 

other. This kind of information can provide 

clues to what actually happens in autism. 

Some of these co-occurring disorders include: 

●	 Epilepsy or seizure disorder—Nearly 

one-third23 of those with autism also show 

signs of epilepsy by adulthood. In most cases, 

medication can control and treat epilepsy 

effectively. 

● Tuberous sclerosis—About 6 percent24 of 

those with autism also have tuberous sclerosis, 

a disorder that shares many symptoms with 

autism, including seizures that result from 

lesions (cuts) on the brain. 

●	 Fragile X syndrome—Nearly 2.1 percent25 of 

those with autism also have Fragile X, the 

most common inherited form of mental 

retardation. 

●	 Mental retardation—About 25 percent26 of 

persons with autism also have some degree of 

mental retardation. 

Many people have treatable conditions in 

addition to their autism. Sleep disorders, 

allergies, and digestive problems are commonly 

seen in those with ASDs, and many of these can 

be treated with environmental interventions 

and/or medication. Treatment for these 

conditions may not cure autism, but it can 

improve the quality-of-life for people who have 

autism and their families. 

10	 11
 
AUTISM RESEARCH AT THE NICHD AUTISM OVERVIEW 

References 

1. Filipek, et al. (2000). Practice Parameter: 

Screening and Diagnosis of Autism—Report 

of the Quality Standards Subcommittee of the 

American Academy of Neurology and the 

Child Neurology Society. Neurology, 55:468-479. 

2. Diagnostic and Statistics Manual, fourth edition. 

(1994). American Psychiatric Association: 

Washington, DC. 

3. Fombonne, 2002; and Gilberg and Wing, 

1999. As cited in: Immunization Safety Review 

Committee, Institute of Medicine, National 

Academy of Sciences. (2004). Immunization 

Safety Review: Vaccines and Autism. National 

Academy Press: Washington, DC. 

4. Immunization Safety Review Committee, 

Institute of Medicine, National Academy of 

Sciences. (2004). Immunization Safety Review: 

Vaccines and Autism. National Academy Press: 

Washington, DC. 

5. Volkmar, 1993; and McLennen, 1993. As 

cited in: Ashley-Koch, et al. (1999). Genetic 

Studies of Autistic Disorder and 

Chromosome 7. Genomics, 61:227-236. 

6. Gillberg, 2000; Chakrabarti, 2001; and 

Chudley, 1998. As cited in: Muhle, et al. (2004). 

The genetics of autism. Pediatrics, 113(5):e472-

e486. 

7. Lord, 1995; Stone, 1999; and Charman, 1997. 

As cited in: Filipek et al. (2000). Practice 

Parameter: Screening and Diagnosis of 

Autism—Report of the Quality Standards 

Subcommittee of the American Academy of 

Neurology and the Child Neurology Society. 

Neurology, 55:468-479. 

8. Cox, 1999; Mars, 1998; Werner, 2000; and 

Baranek, 1999. As cited in: Filipek, et al. 

(2000). Practice Parameter: Screening and 

Diagnosis of Autism—Report of the Quality 

Standards Subcommittee of the American 

Academy of Neurology and the Child 

Neurology Society. Neurology, 55:468-479. 

9. Johnson, CP. (2004). New tool helps primary 

care physicians diagnose autism early. AAP 

News, 24(2):74. 

10. Goldberg, 2003; and Rodier, 1998. As cited 

in: Lord, et al. (2004). Regression and word 

loss in autistic spectrum disorders. Journal of 

Child Psychology and Psychiatry, 45(5):936-955. 

11. Filipek et al. (1999). Screening and diagnosis 

of autistic spectrum disorders. Journal of 

Autism and Developmental Disorders, 29(6): 

439-484. 

12. Filipek et al. (2000). Practice Parameter: 

Screening and Diagnosis of Autism—Report 

of the Quality Standards Subcommittee of the 

American Academy of Neurology and the 

Child Neurology Society. Neurology, 55: 

468-479. 

13. Media Resource Team, American Academy 

of Pediatrics (AAP). (2001). Guidelines on 

Diagnosis and Management of Autism. 

E-News, May 2001 [Electronic Version]. 

Retrieved November 5, 2004, from 

http://www.aap.org/mrt/May01.htm. 

14. Committee on Children with Disabilities, 

AAP. (2001). The pediatrician’s role in the 

diagnosis and management of autistic 

spectrum disorder in children. Pediatrics, 

107:1221-1226. 

15. Committee on Children with Disabilities, 

AAP. (2001). Technical report: The 

pediatrician’s role in the diagnosis and 

management of autistic spectrum disorder in 

children. Pediatrics, 107:e85. Retrieved 

November 4, 2004, from 

http://www.pediatrics.org/cgi/content/full/10 

7/5/385. 

16. Dawson, 1997; Hurth, 1999; Rogers, 1989; 

Hoyson, 1984; Lovaas, 1987; Harris, 1991; 

McEachin, 1993; Greenspan, 1997; Smith, 

1997; and Smith, 1998. As cited in Committee 

on Children with Disabilities, AAP. (2001). 

The pediatrician’s role in the diagnosis and 

management of autistic spectrum disorder in 

children. Pediatrics, 107:1221-1226. 

17. For complete information about the 

reauthorization of IDEA, visit 

http://www.ed.gov/policy/speced/guid/idea/ 

idea2004.html. 

18. For complete information about the 1997 

authorization of IDEA, visit 

http://www.ed.gov/offices/OSERS/Policy/ 

IDEA/regs.html. 

19. Adapted from NICHD, NIH, DHHS. (2003). 

Are there treatments for Fragile X syndrome? 

Families and Fragile X Syndrome (NIH Pub. No. 

03-3402). U.S. Government Printing Office: 

Washington, DC; pages 24-31. 

20. Adapted from: Potenza and McDougle. 

(2001). New Findings on the Causes and Treatment 

of Autism. CNS Spectrums, Medical Broadcast 

Limited. Retrieved November 8, 2004, from 

http://www.patientcenters.com/autism/news/ 

med_reference.html. 

21. Study confirms secretin mo more effective than 

placebo in treating autistic symptoms, NICHD, 

November 2001. Retrieved November 08, 

2004, from 

http://www.nichd.nih.gov/new/releases/news 

key.cfm?from=autism. 

22. Gillberg. (1998). Chromosomal disorders and 

autism. Journal of autism and developmental 

disorders, 28:415-425. 

23. Tuchman, et al. (2002). Epilepsy in autism. 

Lancet Neurology, 1:352-358. 

24. Fombonne, et al. (1997). Autism and 

associated medical disorders in a French 

epidemiological survey. Child and Adolescent 

Psychiatry, 36:1561-1569. 

25. Kielinen, et al. (2004). Associated medical 

disorders and disabilities in children with 

autistic disorder. Autism, 8(1):49-60. 

26. Sigman M, Dissanayake C, Arbelle S, and 

Ruskin E. (1997). Cognition and emotion in 

children with autism. In Cohen and Volkmar 

(Eds.) Handbook of Autism and Pervasive 

Developmental Disorders, second edition (pp. 248-

265). Wiley and Sons: NY. 

The NICHD would like to thank Sally Rogers, 

Ph.D., for her assistance on this fact sheet. 

12 13 
Glossary (Continued)
 

AUTISM RESEARCH AT THE NICHD AUTISM OVERVIEW 

Glossary 

The word... Is pronounced... And means... 

Applied Behavior 

Analysis 

ah-PLYED 

bee-HAY-vyur 

ah-NALL-uh-siss 

An intervention that relies on the theory that rewarded 

behavior is more likely to be repeated than ignored behavior. 

This theory provides the foundation of several different 

methods of behavioral management often used with persons 

who have autism and other developmental disorders. 

Behavior 

Management 

Therapy 

bee-HAY-vyur 

MANN-ej-ment 

thee-ree 

A method of therapy that focuses on managing behavior— 

that is, changing unwanted behaviors through rewards, 

reinforcements, and by confronting something that arouses 

anxiety, discomfort, or fear and overcoming the unwanted 

responses. 

Chromosomes kro-mu-SOM One of the "packages" of genes and other DNA in the 

nucleus of a cell. Humans have 23 pairs of chromosomes, 

46 in all. Each parent contributes one chromosome to each 

pair, so children get half of their chromosomes from their 

mothers and half from their fathers. 

Developmental 

screening 

dee-vel-up-menn-tul 

skree-ning 

A check-up similar to the physical check-up a child gets from 

a health care provider, but that focuses on a child's social, 

emotional, and intellectual development. This screening 

monitors and charts development to make sure that the child 

is developing as expected for his or her age. 

Epidemiological 

studies 

epp-ih-DEEM-me-ohloj-i-kul 

STUH-dees 

Studies of the number of people with a disease(s), the 

locations of these people, the patterns of the disease(s), and 

what contributes to or causes the disease(s) or related 

events in certain groups. 

Epilepsy epp-ih-LEPP-see A brain disorder in which clusters of nerve cells, or neurons, 

in the brain sometimes signal abnormally. In epilepsy, the 

normal pattern of neuronal activity becomes disturbed, 

causing strange sensations, emotions, and behavior or 

sometimes convulsions, muscle spasms, and loss of 

consciousness. 

Fragile x 

syndrome 

FRA-jell EKS 

sinn-DROM 

Is the most common form of inherited mental retardation. A 

mutation in a single gene, the FMR1 gene located on the X 

chromosome, causes Fragile X syndrome and can be 

passed from one generation to the next. Symptoms of 

Fragile X syndrome occur because the mutated gene cannot 

produce enough of a protein that is needed by the body’s 

cells, especially cells in the brain, to develop and function 

normally. 

Gene jeen Pieces of DNA. They contain the information for making a 

specific protein. 

The word... Is pronounced... And means... 

Individual Education 

Plan (IEP) 

INN-div-ih-djewel 

ED-djew-kay-shun 

plan 

A written set of instruction goals, or specific skills, for 

every child in a special education program that is 

required by law. The document is an agreement 

between the school and the family about a child's 

educational goals. The IEP is reviewed every year and, 

if needed, changed to meet a child’s new or changing 

needs. 

Mental retardation MENN-tul 

ree-tarr-DAY-shen 

A term used when a person has certain limitations in 

mental functioning and in skills such as communicating, 

taking care of him or herself, and social skills. 

Prevalence prev-uh-lens The number of people in a given population who have a 

certain condition or disease. 

Replicate repp-li-KATE Describes a situation in which many studies that use the 

same methods and steps have gotten the same 

outcome, suggesting that a finding is likely to be true. 

Rett syndrome RETT sinn-DROM Mostly caused by mutations in the MECP2 gene on the 

X chromosome. Rett syndrome is a disorder of brain 

development that occurs almost exclusively in girls. 

After a few months of apparently normal development, 

affected girls develop problems with language, learning, 

coordination, and other brain functions. 

Seizures SEE-jurs A sudden attack, often one of convulsions, as in 

epilepsy. Seizures don’t necessarily involve movement 

or thrashing; they can also make someone seem as 

though they are frozen, unmoving. 

Stereotyped 

Behaviors 

STARE-ee-oh-tipd 

bee-HAY-vyurs 

Actions that are repeated without change. 

Susceptibility suss-ept-ih-BULL The state of being predisposed to, sensitive to, or of 

lacking the ability to resist manifestations of something 

(such as a pathogen, familial disease, or a drug); a 

person who is susceptible is more likely to show 

symptoms of a disorder. 

Tuberous sclerosis TOOB-er-us 

sklar-OH-siss 

A rare, multi-system genetic disease that causes noncancerous tumors to grow in the brain and on other vital 

organs such as the kidneys, heart, eyes, lungs, and 

skin. It commonly affects the central nervous system 

and results in symptoms including seizures, 

developmental delay, behavioral problems, skin 

abnormalities, and kidney disease. 

14 15
 
AUTISM RESEARCH AT THE NICHD
 

How can I get involved with stu

If you are interested in taking part in one of the C

one of the CPEA sites, visit http://www.nichd.nih.g

welcome to take part in many different studies, bu

time. 

To find out what studies related to autism are curr

http://www.nichd.nih.gov/autism/research.cfm and ch

patients” link. 

You can also visit http://www.clinicaltrials.gov or ca

funded studies that are seeking participants. 

Where can I go for more inform

For more information about the CPEA Netw

contact the NICHD. The NICHD supports a

health of children, adults, families, and pop

disabilities. The mission of the NICHD is to 

wanted, that women suffer no harmful effec

c h i l d ren have the chance to fulfill their pote

disease or disability, and to ensure the hea

of all people through optimal rehabilitation

NI CHD In fo r m a tio n R es o ur c e C en ter a t : 

M a i l : P.O. Box 3006, Rockville, MD 20847 

Ph on e: 1-800-370-2943 (TTY: 1-888-320-6942) 

F a x : (301) 984-1473 

E - m a i l : N I C H D I n f o rm a t i o n R e s o u rceCenter@mail.nih

I n t e r n e t : h t t p : / / w w w. n i c h d . n i h . g o v / a u t i s m 

The National Library of Medicine also provide

http://www.nlm.nih.gov/medlineplus/autism.h

about ASDs at http://health.nih.gov/result.asp

16