What is autism?

Autism is a disorder of child development characterized by three main features:

• poor social interaction
• limited ability to communicate
• limited repertoire of activities and interests

Autism is not a single discrete condition.  It falls within a spectrum of problems grouped under the category of “pervasive developmental disorders.” Pervasive developmental disorders are characterized by delays in the development of socialization and communication skills. [1] [NIDNS, 2006]

Common signs of autism are:

• undeveloped or poorly developed verbal and nonverbal communication skills
• abnormal speech patterns
• impaired ability to sustain a conversation
• abnormal social play
• lack of empathy towards others
• inability to make friends
• quirky, repetitive body movements
• marked need for sameness
• very narrow interests
• preoccupation with parts of the body
• minimal eye contact

There is a spectrum of severity of these symptoms that range from the most dramatic and stereotypic form of autism where children will have limited or no speech, prefer to engage in repetitive motor or sensory behaviors and do not relate much to other people except in times of need, through to the other end of the spectrum where individuals may be quite articulate with a high IQ and appear to function relatively well with features that may not be readily detectable, this condition is often called Asperger syndrome. In the mid-range of the spectrum are those individuals with a variety of diagnostic symptoms with varying severity. These children are diagnosed with Pervasive Developmental Disorder [of Childhood] – Not Otherwise Specified or simply PDD(NOS) [2]
According to the CDC National Center for Health Statistics, the diagnosis of autism spectrum disorders has increased during the past two decades from 4-5 children per 10,000 in the 1980’s to 30-60 children per 10,000 in the 1990’s. However, it is unclear whether the incidence of autism is actually increasing or whether the increase is a result of increased awareness, changes in the diagnostic criteria, and improvements in detecting the set of conditions on the spectrum.  At present no studies have been able to conclusively determine if the incidence of autism and other conditions on the autism spectrum have actually increased in the U.S. or worldwide. [3]

What are the causes of autism?

The cause for autism is currently unknown.  It is clear that autism has a genetic component and tends to run in families. [4] It is likely that both genetic and environmental factors have a role in causing autism.  Possible causes of autism include:

• complex genetic abnormalities [8-10]
• altered levels of chemical signals in the womb [6]
• problems with movement of nerve cells in the brain during early brain development [7]
• problems with closure of the neural tube (an early developmental structure related to the spinal cord) [12]
• exposure to certain medications associated with birth defects in the womb, such as thalidomide and valproic acid [Rodier and Hyman, 1998] [11]
• environmental exposures, sometimes even at low levels which do not produce abnormalities in other individuals
• limited ability to detoxify environmental exposures, even at low levels

Can environmental exposures cause autism?

At this point, there is little evidence that environmental exposures can cause autism.  One incident suggestive of a possible link between environmental exposures and autism is the Brick Township cluster in New Jersey.  This town is located close to several Superfund sites (hazardous waste sites).   The Centers for Disease Control and Prevention (CDC) found that autism was more common in this site than in the general population. [13] However, these results could have happened completely by chance.

The Agency for Toxic Substances and Disease Registry (ATSDR) found that three environmental contaminants, tetrachloroethylene, trichloroethylene, and trihalomethanes, were in the drinking water of Brick Township, NJ several times in the past.  However, this information must be interpreted with great caution.  There was no relationship between the location and timing of these abnormal chemical levels and cases of autism.  [14]  This example emphasizes the pressing need for more research into possible connections between environmental exposures and autism.

One of the most contentious issues in the environmental etiology of autism is the question of vaccines, the use of thimerosal (a mercury containing substance used as a preservative in vaccines), of mercury itself and of other so called “heavy metals”. This issue has unfortunately resulted in law suits and has split families apart. The Institute of Medicine Immunization Safety Review Committee examined the hypothesis that vaccines, specifically the measles-mumps-rubella (MMR) vaccine and thimerosal-containing vaccines, are causally associated with autism [20]:

“…the committee concludes that the evidence favors rejection of the causal relationship between thimerosal-containing vaccines and autism.”

“… the committee concludes that the evidence favors rejection of a causal relationship between MMR vaccine and autism”

“Because chelation therapy has potential serious risks, the committee recommends that it be used only in carefully controlled research settings….”

“The committee does not recommend a policy review ….. of vaccines”

Conclusion:

1. There is no evidence at present that autism is a mercury toxicity syndrome
2. There is no evidence at present that autism is related to vaccination
3. There is no evidence at present that autism is improved by chelation

Given the evidence that autism has a genetic component, environmental exposures may play a role in the development of autism through gene-environment interactions in susceptible individuals. [21]   Several studies are currently underway to examine this interaction, which include the Childhood Autism Risks from Genetics and the Environment (Charge), Autism Birth Cohort (ABC) Study, and the Centers for Autism and Developmental Disabilities Research and Epidemiology (CADDRE). [3]   These initiatives and many other studies will hopefully provide useful insight into the genetic and environmental causes of autism and other autism spectrum disorders.

Given the evidence that autism has a genetic component, environmental exposures may play a role in the development of autism through gene-environment interactions in susceptible individuals. [21]   Several studies are currently underway to examine this interaction, which include the Childhood Autism Risks from Genetics and the Environment (Charge), Autism Birth Cohort (ABC) Study, and the Centers for Autism and Developmental Disabilities Research and Epidemiology (CADDRE). [3]   These initiatives and many other studies will hopefully provide useful insight into the genetic and environmental causes of autism and other autistic spectrum disorders.

What can be done for a child with autism?

The most important aspect of helping children who have autism and related conditions is to start treatment as early as possible. For this reason it is important to identify infants and young children as early as possible.

The CDC has done much work in this area to promote early identification, particularly among pediatricians. If you suspect your child may have autism, see your child's pediatrician. Pediatricians are trained to refer autistic children to doctors who specialize in helping them.

For all children under the age of 3 years living in any of the United States there is a service offered by the State that provides early intervention and more often than not therapists will come to the home and evaluate the child and do the therapies in the home. There are also specialists who work with children on the autism spectrum called Developmental Pediatricians, as well as psychologists and therapists who have expertise in helping children with Autism. The most important and effective approaches to treatment and management are as follows:

• Speech Therapy as soon as possible and as much as possible to work on speech. language and communication
• Occupational Therapy or OT to work on coordination and on problems of sensory integration. If there is a significant motor problem a Physical Therapist (PT) may also be needed
• It is also critical to help children to learn to communicate, interact and socialize and for this reason programs that work on these skills are very important. Some of these are “Floortime”, Applied Behavior Analysis or ABA, Relationship Development Intervention or RDI among others
• It is most important to understand the needs of the children in order to prevent unnecessary anxiety and stress therefore, maintaining a structured environment with predictability is very helpful
• Family activities and especially siblings and cousins are most beneficial as they encourage adaptation to every day communication, interaction and socialization
• Children with autism spectrum disorders are more likely to need special education services which will be provided by the local public schools. It is important for the parents to have a clear diagnosis and work with the school, pediatricians, therapists and psychologists to make sure that the child is in the best possible program with a teacher who understands, accepts and appreciates the child.
• Some children may have additional difficulties such as learning disabilities, attention deficit hyperactivity disorder (ADHD), anxiety, obsessive compulsive disorders or other emotional, psychological and behavioral conditions that interfere with school or socialization and some may have more serious behavior disorders such as aggression, self injurious behaviors or pica and may require more intense behavior management programs as well as medication. It is best for the family to consult their pediatrician, a developmental pediatrician or a child psychiatrist to get the best advice.
• Many children benefit from such therapies as Hippotherapy (therapeutic horse riding), Aquatherapy or Hydrotherapy (therapy in the water), music therapy or even other activities like Karate of gymnastics
• Some children may have such restrictive eating habits that they may need  nutritional supplements and may need to consult a nutritionist
• Some children may have vision or hearing problems and need to see the appropriate specialist
• Some children may have gastrointestinal disorders such as constipation or diarrhea and may need to see a gastroenterologist
• Children with autism, like any other children, can have any other medical conditions and need to see the appropriate specialist or therapist
• Some people advocate special diets and supplements, these need to be discussed with the child's pediatrician
• With so many necessary therapists and specialists families may need coordination of care and this may be provided by the pediatricians through the Medical Home concept or through an Autism clinics or Developmental Pediatrician
• As the child gets older there will be changing needs and with the emergence of puberty and eventually the likelihood of graduation from school and entering adulthood, it is important for families to consult the appropriate school personnel, therapist, pediatricians and other programs and agencies. coordinating speech and language therapy and particularly may need help in enhancing their social skills
• It is also important for families to be aware that there are many sensational promises of “cure” or benefit that are offered – most commonly on the internet – and that their benefit may not be what the promoters promise so caution should be exercised.

Some clinicians recommend that autism be treated with chelators, drugs that bind specific metals and speed their elimination from the body. There is no published evidence that chelation offers long-term improvement in children with autism. Therefore, in the absence of proven high levels of specific metals, we do not recommend the use of chelating drugs for children with autism.
The Autism Society of America gives the following message:

"With appropriate services, training, and information, most families are able to support their son or daughter [with autism] at home. Group homes, assisted apartment living arrangements, or residential facilities offer more options for out of home support.  Autism-specific programs and services provide the opportunity for individuals to be taught skills that allow them to reach their fullest potential." [22]

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Additional Resources
Autism Society of America
Autism Society of America- Greater Georgia Chapter
Autism Birth Cohort Study
CDC Autism Information Center
Centers for Autism and Developmental Disabilities Research and Epidemiology
Childhood Autism Risks from Genetics and the Environment Study
NINDS Pervasive Developmental Disorders Information Page
www.autismspeaks.org/

References

[1] National Institute of Neurological Disorders and Stroke. Pervasive Developmental Disorders Information Page. 2006.  Available online at: <http://www.ninds.nih.gov/disorders/pdd/pdd.htm>.

 [2] London EA, Etzel R.   The environment as an etiologic factor in autism: a new direction for research. Environmental Health Perspectives 2000;108 Suppl 3:401-4.

[3] Szpir M.  Tracing the origins of autism: A spectrum of new studies. Environmental Health Perspectives 2006 114:A412-A418.

 [4] Risch N, Spiker D, et al. A genomic screen of autism: evidence for a multilocus etiology. American Journal of Human Genetics 1999; 65(2):493-507.

[5] Folstein SE, Rutter ML. Autism: familial aggregation and genetic implications.  Journal of Autism & Developmental Disorders 1988;18(1):3-30.

[6] Robinson PD, Schutz CK, et al.  Genetically determined low maternal serum dopamine beta-hydroxylase levels and the etiology of autism spectrum disorders. American Journal of Medical Genetics 2001;100(1):30-6.

[7] Bailey A, Luthert P, et al.  A clinicopathological study of autism.  Brain 1998;121 ( Pt 5):889-905.

[8] Auranen M, Nieminen T, et al.  Analysis of autism susceptibility gene loci on chromosomes 1p, 4p, 6q, 7q,13q, 15q, 16p, 17q, 19q and 22q in Finnish multiplex families. Molecular Psychiatry 2000;5(3):320-2.

[9] Barrett S, Beck JC, et al.  An autosomal genomic screen for autism. Collaborative linkage study of autism. American Journal of Medical Genetics 1999; 88(6):609-15.

[10] Rutter M. Genetic studies of autism: from the 1970s into the millennium. Journal of Abnormal Child Psychology 2000;28(1):3-14.

[11] Ingram JL, Peckham SM, et al.  Prenatal exposure of rats to valproic acid reproduces the cerebellar anomalies associated with autism. Neurotoxicology & Teratology 2000;22(3):319-24.

[12] Rodier PM, Ingram JL, et al. origin for autism: developmental anomalies of the cranial nerve motor nuclei. Journal of Comparative Neurology 1996;370(2):247-61.

[13] CDC. Prevalence of Autism in Brick Township, New Jersey, 1998.  Community report. Atlanta, GA: Centers for Disease Control and Prevention 2000.

[14] ATSDR. Brick Township Investigation. Atlanta, GA: Agency for Toxic Substances and Disease Registry, 2000.

[15] Wakefield AJ, Murch SH, et al.  Ileal-lymphoid-nodular hyperplasia, nonspecific colitis, and pervasive developmental disorder in children. Lancet 1998;351:367-641.

[17] Kaye JA, Jick H, et al.  Mumps, measles, and rubella vaccine and the incidence of autism recorded by general practitioners: a time trend analysis. BMJ 2001;322(7284):460-3.

[18] DeStefano F, Chen RT. Autism and measles, mumps, and rubella vaccine: No epidemiological evidence for a causal association. Journal of Pediatrics 2000; 136(1):125-6.

[19] Taylor B, Miller E, et al. Autism and measles, mumps, and rubella vaccine: no epidemiological evidence for a causal association. Lancet 1999;353(9169):2026-9.
[20] Institute of Medicine Immunization Safety Review: Thimerosal-Containing Vaccines and Neurodevelopmental Disorders May 2004

[21]  Newschaffer CJ, Fallin D, and Lee NL.  Heritable and nonheritable risk factor for autism spectrum disorders.  Epidemiologic Review 2002 24:137-153.

 [22] Autism Society of America.  http://www.autism-society.org.
Rodier PM, Hyman SL. Early environmental factors in autism. Mental Retard Dev Disabil Res Rev 4:121-128(1998).

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