Autism spectrum disorders (ASD) are a group of complex neurodevelopmental disabilities that affect a child’s social, behavioral, and communication skills. In people with these disorders, their brains handle information differently than most people’s do. These disorders include autistic disorder (or “classic” autism), Asperger’s syndrome, and pervasive developmental disorder not otherwise specified (PDD-NOS, for short). Autism lies on the more severe end of the spectrum, whereas Asperger’s is a milder condition that doesn’t involve speech impairment (as classic autism does); PDD-NOS, by contrast, is a catch-all diagnosis for when a child has some symptoms of autism or Asperger’s but doesn’t meet all the specific criteria for either one.
While people with ASDs tend to have some symptoms in common -- like problems with social interaction and repetitive behaviors -- ASDs affect people in highly individual ways and can range in severity from mild to very serious within each disorder. Someone with mild autism may simply seem quirky and lead a fairly normal life. Meanwhile, some kids with more severe autism or other PDD-NOS may seem to be locked in their own worlds, unable to connect or relate to others. They may be more inclined to run along the length of a playroom than to join a group of kids playing together in the middle. Meanwhile, those who have high-functioning autism or Asperger’s syndrome may struggle with negotiating the nuances of social interactions; they might invade other children’s personal space, take things other people say quite literally (making them unable to “get” jokes), or have trouble with the concept of pretend play.
Currently, it’s estimated that one in every 110 children is diagnosed with autism, and 1.5 million people in the U.S. are affected by it. The rate of autism has been increasing by 10 to 17 percent annually, prompting some people to say we’re in the midst of an autism epidemic, but that’s hardly the case. While some of the increase may be real, much of it may be due to better recognition of the disorders by professionals and the public, as well as to changes in the criteria that are used to diagnose ASDs.
Many experts believe that a combination of genetic and environmental factors determine a person’s risk of developing an ASD. While these disorders occur among children of all races, ethnicities, and socioeconomic groups, they are four to five times more likely to occur among boys, according to the Centers for Disease Control and Prevention (CDC). If one identical twin has an ASD, the other has at least a 60 percent chance of having one, too, according to the CDC.
While there’s no cure for ASDs, research continues to untangle the roots and complexities of these disorders -- and early intervention can greatly improve a child’s development. In fact, the sooner a child is diagnosed, the sooner treatments can be introduced, and the sooner a child can be helped, developmentally, socially, and behaviorally. This will improve the chances that a child with an ASD will reach his or her full potential.
Currently, it’s estimated that one in every 110 children is diagnosed with autism, and 1.5 million people in the U.S. are affected by it. The rate of autism has been increasing by 10 to 17 percent annually, prompting some people to say we’re in the midst of an autism epidemic, but that’s hardly the case. While some of the increase may be real, much of it may be due to better recognition of the disorders by professionals and the public, as well as to changes in the criteria that are used to diagnose ASDs.
Many experts believe that a combination of genetic and environmental factors determine a person’s risk of developing an ASD. While these disorders occur among children of all races, ethnicities, and socioeconomic groups, they are four to five times more likely to occur among boys, according to the Centers for Disease Control and Prevention (CDC). If one identical twin has an ASD, the other has at least a 60 percent chance of having one, too, according to the CDC.
While there’s no cure for ASDs, research continues to untangle the roots and complexities of these disorders -- and early intervention can greatly improve a child’s development. In fact, the sooner a child is diagnosed, the sooner treatments can be introduced, and the sooner a child can be helped, developmentally, socially, and behaviorally. This will improve the chances that a child with an ASD will reach his or her full potential.
While the exact symptoms of ASDs can be highly individual, varying considerably from one affected child to another, the primary symptoms tend to fall into three broad categories: communication challenges, problems with social interaction, and repetitive behaviors or interests. Some may also have sensitivity to sensory experiences such as loud sounds and the bustle of a large crowd. Each of these sets of difficulties can range from very mild to very severe in a particular child, and they can even be fluid over time in the same child.
“Some kids might look more like they have autism one day, Asperger’s another,” says James Coplan, M.D., owner of Neurodevelopmental Pediatrics of the Main Line in Rosemont, PA, and author of Making Sense of Autistic Spectrum Disorders.“The disorders can blur into each other.” Signs and symptoms of ASDs usually begin before a child turns 3, though some children with ASD appear to develop normally then regress, often between their first and second birthdays. At that point, they may become withdrawn, silent, and disinterested in interacting with others. They may stop developing new skills or they may lose the language and social skills they had already mastered.
Communication Challenges
When it comes to communication issues, ASD problems can relate to both verbal and nonverbal communication. Some children with severe autism may be mute for most if not all of their lives. For others, language may be delayed or they may not speak in the usual ways; they might struggle to combine words into meaningful sentences, speak only in single words, or repeat the same phrase over and over. Others may only be able to parrot what they hear others saying, a condition called echolalia. Meanwhile, others may have fairly normal language skills but may have difficulty maintaining a conversation. Children with Asperger’s syndrome, by contrast, may be super verbal. “They’re like little professors -- they’ll talk your ear off about whatever topic they’re interested in and they don’t understand that other people don’t share that interest,” Dr. Coplan says.
Problems With Social Interaction
On the social front, an infant with ASD may be unresponsive to people, may resist being held or cuddled by parents, or focus exclusively on one object while ignoring others for long periods of time. Children with ASD may avoid eye contact with other people and may not answer to their name. Because they don’t understand social cues like facial expressions or tone of voice, children with ASDs have trouble interpreting what others are thinking or feeling. They may lack empathy as well. In other words, they just don’t get the give-and-take of everyday social interactions.
Repetitive Movements or Interests
In addition, many children with ASD engage in repetitive movements such as flapping their arms or hands, walking on their toes, rocking their bodies, or spinning in circles. They may also develop self-injuring behaviors like head-banging. Sometimes they do this to self-soothe; other times, they do it to stimulate themselves (what’s often called “stimming”). “Stimming behaviors are most evident during the preschool years and usually become less prominent as the child gets older, although they may re-emerge from time to time when the child becomes very excited or upset,” says Dr. Coplan. Children with ASDs also often play in repetitive ways -- lining up their trains in a particular formation, for example -- or they become fascinated with small parts of objects or odd items (like rubber bands). Others have obsessive interests (in robots or space, for example) and talk about them incessantly (in the case of Asperger’s) even if their companion doesn’t share their preoccupation; as these children get older, they may develop an encyclopedic knowledge and be able to recite long lists of facts and figures about their passionate interest, which can make them seem highly intelligent. All of these attributes can be found individually in children without ASDs, but talk to your doctor if your child exhibits several or many of these behaviors.
Although it’s not one of the main diagnostic criteria, doctors also look out for unusual responses to sensory experiences; kids with ASDs may be hyper- or hypo-sensitive to the way things sound, look, smell, taste, or feel. (However, many kids have sensory sensitivities but don’t have an ASD.) They may be driven to meltdowns by the sensation of a shirt tag rubbing against their or they may be completely intolerant of mushy foods. They might freak out when a fire truck drives by with its siren blaring or have a four-alarm fit in a crowded, brightly lit department store. And they may become highly upset by minor changes to their environments or routines. Meanwhile, others seek more stimulation -- by continuously spinning in circles on the playground or being a serial hugger in preschool (not because they’re truly affectionate but because they crave the sensation of pressure against their bodies).
At this point, the causes of ASDs remain unknown, and more research needs to be done. It’s likely, according to Dr. Coplan, that genetic factors probably account for the majority of cases of ASDs. In most families with a child on the spectrum, doctors also find a sizeable increase in related disorders such as depression, anxiety disorder and OCD. Although there has been a lot of talk in the press about possible environmental causes, there is very little evidence to support these theories or fears. Research has identified a number of genes associated with ASDs, and preliminary studies have found that people with ASDs have irregularities in several regions of the brain or abnormal levels of neurotransmitters in their brains, according to the National Institute of Neurological Disorders and Stroke.
It’s also known that ASDs are more likely to occur in people who have other medical conditions such as Fragile X syndrome (a genetic condition that involves mental retardation), tuberous sclerosis (a condition in which benign tumors grow on the brain), Down syndrome (a genetic disorder that causes physical abnormalities and delayed mental and social development), Tourette syndrome (a neurological disorder characterized by repetitive, involuntary movements and tics), epileptic seizures, and other chromosomal disorders. And there’s some evidence linking the use of prescription drugs -- such as thalidomide and valproic acid -- during pregnancy with a higher risk of ASDs. Indeed, the critical period for developing ASDs may occur before birth.
Vaccines and Autism
Contrary to what some people believe, poor parenting practices and vaccines do not cause autism spectrum disorders. Some parents are concerned that the MMR vaccine (for measles, mumps, and rubella), in particular, causes autism. This is based, in part, on a famous 1998 research paper by a British researcher, claiming that the MMR vaccine could cause autism. Earlier this year, The Lancet retracted that paper, based on the researcher’s scientific methods and financial conflicts, and the he lost his license in his native UK. Meanwhile, many studies have examined whether there is a relationship between vaccines and autism spectrum disorders, and study after study has found that vaccines are not associated with ASDs.
Thimerosal and Autism
Another concern stems from whether the mercury-based preservative thimerosal (which is no longer used in most vaccines) could cause autism but a thorough review by the Institute of Medicine found no such link. As the National Institute of Child Health and Human Development puts it, “There is no conclusive scientific evidence that any part of a vaccine or combination of vaccines causes autism, even though researchers have done many studies to answer this important question. There is also no proof that any material used to make or preserve the vaccine plays a role in causing autism.”
Diagnosing ASDs can be tricky since there’s no definitive test, like a blood test or an X-ray, that can indicate for certain that a child has one of these disorders. Instead, a doctor makes the diagnosis based on parents’ descriptions and observations of their child, as well as his clinical evaluations of a child’s behavior and development. “It’s a clinical judgment regarding where a child falls on the spectrum; it’s not clear-cut and that’s where there can be error in coming up with these diagnoses,” says Michelle Rowe, Ph.D., executive director of the Kinney Center for Autism Education and Support and professor of health services at St. Josephs University in Philadelphia.
Age of Diagnosis
If you have even the slightest suspicion that your child may have an ASD, share your concerns with your pediatrician right away. He or she may refer you to a specialist -- such as a developmental pediatrician, a child neurologist, a child psychologist or psychiatrist -- who can do a more in-depth evaluation of your child in order to make the correct diagnosis. You can also contact your state’s public early intervention system -- as a starting point, look up your state’s services at:www.nichcy.org/Pages/StateSpecificInfo.aspx -- to have your child evaluated to see if he qualifies for state-funded intervention such as speech therapy, occupational therapy or other services; you don’t need to wait for a physician’s diagnosis or referral.
Signs of ASDs can usually be seen in infants and toddlers, and early intervention therapies can make a big difference in a child's development. Unfortunately, the disorders can’t be reliably diagnosed until somewhere between 18 months and three years. And the reality is, it often happens later than that: after reviewing data from 13 sites participating in the CDC’s ongoing autism surveillance program, researchers at Washington University in St. Louis recently found that the median age of identification for children with ASDs is 5.7 years. The delay can mean that young children with an ASD might not get the beneficial therapies they need from an early age.
Diagnostic Criteria
To diagnose ASDs, physicians use criteria from the American Psychiatric Association’s Diagnostic and Statistical Manual-IV (DSM-IV). Symptoms must be ongoing, not temporary, and severe enough to have a considerable impact on a child’s life and ability to function. Here’s how the three different disorders stack up:
Autism
Autistic disorder (or “classic” autism), which is what most people think of when they hear the word “autism,” typically involves significant language delays, social and communication impairments, and unusual behaviors and interests. Many children with this form of autism also have intellectual disabilities, though not all do. “People with autism are fairly disconnected in a behavioral way,” Dr. Rowe says. “They may hear everything going on but not have the expressive language skills to respond in the same way as their peers.”
A child must have six or more of the following characteristics, including at least two from the first category and one each from the second and third categories:
Marked difficulties in social interactions, including at least two of the following:
- Problems in the use of multiple nonverbal behaviors such as eye-to-eye contact, facial expressions, body postures, and gestures to regulate social interaction
- Failure to develop relationships with peers in a way that’s appropriate to the child’s developmental level
- A lack of spontaneous efforts to share enjoyment, interests, or achievements with other people
- A lack of social or emotional reciprocity
Marked impairments in communication abilities, including at least one of the following:
- A delay in or total lack of the development of spoken language (not accompanied by an attempt to compensate through alternative modes of communication such as gesture or mime)
- Serious problems with initiating or sustaining a conversation with others (in children who have adequate speech)
- Repetitive use of language or idiosyncratic language
- Lack of varied, spontaneous make-believe play or social imitative play that’s appropriate to the child’s developmental level
Restricted, repetitive patterns of behavior, interests, and activities, including at least one of the following:
- A severe preoccupation with one or more interests that is abnormal in intensity or focus
- A seemingly inflexible adherence to specific, nonfunctional routines or rituals
- Repetitive motor patterns such as hand flapping or body rocking
- A persistent preoccupation with parts of objects
Asperger’s syndrome
With Asperger’s syndrome, people usually have milder versions of the social challenges and unusual behaviors and interests that are associated with classic autism. These children usually do not have difficulties with speech or nonverbal communication, nor do they have intellectual disabilities. “People with Asperger’s typically have good speech and cognitive function but they have difficulty communicating with people in a socially acceptable way,” Dr. Rowe says. “They know something’s different about them, and they can feel misunderstood when they try to make connections with people, but they don’t know how. This can leave them feeling angry or depressed.”
With Asperger’s syndrome, people usually have milder versions of the social challenges and unusual behaviors and interests that are associated with classic autism. These children usually do not have difficulties with speech or nonverbal communication, nor do they have intellectual disabilities. “People with Asperger’s typically have good speech and cognitive function but they have difficulty communicating with people in a socially acceptable way,” Dr. Rowe says. “They know something’s different about them, and they can feel misunderstood when they try to make connections with people, but they don’t know how. This can leave them feeling angry or depressed.”
The following criteria are used to diagnose Asperger's:
Problems with social interaction including at least two of the following:
- Trouble using nonverbal behavior such as eye-to-eye contact, facial expressions, body postures, and gestures to regulate social interactions
- Failure to develop relationships with peers in a ways that’s appropriate to the child’s age and stage of life
- A lack of spontaneous efforts to share enjoyment, interests, or achievements with other people
- A lack of social or emotional reciprocity
Restricted, repetitive patterns of behavior, interests, and activities, including at least one of the following:
- A severe preoccupation with one or more interests that is abnormal in intensity or focus
- A seemingly inflexible adherence to specific, nonfunctional routines or rituals
- Repetitive motor patterns such as hand flapping or body rocking
- A persistent preoccupation with parts of objects
These developmental disturbances cause significant problems in social interactions, at school, and in other important areas of a child’s life. There’s no significant delay in language development (in other words, the child is uttering single words by age two and using phrases by age three). There’s also no significant delay in cognitive development or in the development of age-appropriate abilities to do things for himself, in adaptive behavior or in curiosity about the child’s own environment.
Pervasive Developmental Disorder Not Otherwise Specified (PDD-NOS)
With PDD-NOS, which is sometimes called “atypical autism,” a person may have some symptoms of classic autism and some symptoms of Asperger’s syndrome but not enough to be diagnosed with either one. Children with PDD-NOS typically have fewer and more mild symptoms than those with “classic” autism but they may have communication problems (whereas those with Asperger’s don’t). According to the DSM-IV, this diagnosis is used when a child has a severe and pervasive impairment in her development of reciprocal social interaction, an impairment that’s related to problems with verbal or nonverbal communication skills or to the presence of repetitive behavior, interests, and activities. Other conditions, such as schizophrenia, must also be ruled out before a child can receive this diagnosis.
Complicating matters, a panel of experts working on the DSM-V is proposing to eliminate the individual ASD classifications and use a new general category called “autism spectrum disorders” instead. These proposed changes are somewhat controversial because it isn’t clear how they would affect the availability of support services for people with ASDs, and some people with Asperger’s syndrome are particularly upset about the elimination of their diagnosis. At this point, the changes are not a done deal and are still being debated; the new DSM-V will be published in 2013.
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