Autism Spectrum Disorders (Pervasive Developmental Disorders) (continued)

Because mothers pass on only X chromosomes to their children, if the mother has the altered gene for Fragile X, she can pass that gene to either her sons or her daughters. If the mother has the mutated gene on one X chromosome and has one normal X chromosome, and the father has no genetic mutations, all the children have a 50-50 chance of inheriting the mutated gene.

The odds noted here apply to each child the parents have.³
In terms of prevalence, the latest statistics are consistent in showing that 5% of people with autism are affected by fragile X and 10% to 15% of those with fragile X show autistic traits.

Medications

On October 6, 2006 the U.S. Food and Drug Administration (FDA) approved risperidone (generic name) or Risperdal (brand name) for the symptomatic treatment of irritability in autistic children and adolescents ages 5 to 16. The approval is the first for the use of a drug to treat behaviors associated with autism in children. These behaviors are included under the general heading of irritability, and include aggression, deliberate self-injury and temper tantrums.

Olanzapine (Zyprexa) and other antipsychotic medications are used “off-label” for the treatment of aggression and other serious behavioral disturbances in children, including children with autism. Off-label means a doctor will prescribe a medication to treat a disorder or in an age group that is not included among those approved by the FDA.

Other medications are used to address symptoms or other disorders in children with autism. Fluoxetine (Prozac) and sertraline (Zoloft) are approved by the FDA for children age 7 and older with obsessive-compulsive disorder. Fluoxetine is also approved for children age 8 and older for the treatment of depression.

Fluoxetine and sertraline are antidepressants known as selective serotonin reuptake inhibitors (SSRIs). Despite the relative safety and popularity of SSRIs and other antidepressants, some studies have suggested that they may have unintentional effects on some people, especially adolescents and young adults. In 2004, after a thorough review of data, the Food and Drug Administration (FDA) adopted a “black box” warning label on all antidepressant medications to alert the public about the potential increased risk of suicidal thinking or attempts in children and adolescents taking antidepressants. In 2007, the agency extended the warning to include young adults up to age 25. A “black box” warning is the most serious type of warning on prescription drug labeling. The warning emphasizes that children, adolescents and young adults taking antidepressants should be closely monitored, especially during the initial weeks of treatment, for any worsening depression, suicidal thinking or behavior, or any unusual changes in behavior such as sleeplessness, agitation, or withdrawal from normal social situations.

Disorders/Vaccinations

The Institute of Medicine (IOM) conducted a thorough review on the issue of a link between thimerosal (a mercury based preservative that is no longer used in vaccinations) and autism. The final report from IOM, Immunization Safety Review: Vaccines and Autism, released in May 2004, stated that the committee did not find a link.

Until 1999, vaccines given to infants to protect them against diphtheria, tetanus, pertussis, Haemophilus influenzae type b (Hib), and Hepatitis B contained thimerosal as a preservative. Today, with the exception of some flu vaccines, none of the vaccines used in the U.S. to protect preschool aged children against 12 infectious diseases contain thimerosal as a preservative. The MMR vaccine does not and never did contain thimerosal. Varicella (chickenpox), inactivated polio (IPV), and pneumococcal conjugate vaccines have also never contained thimerosal.

A U.S. study looking at environmental factors including exposure to mercury, lead and other heavy metals is ongoing.

References for the Addendum

¹Yeargin-Allsopp M, Rice C, Karapurkar T, Doernberg N, Boyle C, Murphy C. Prevalence of Autism in a US Metropolitan Area. The Journal of the American Medical Association. 2003 Jan 1;289(1):49-55.

²Powers MD. What Is Autism? In: Powers MD, ed. Children with Autism: A Parent's Guide, Second Edition. Bethesda, MD: Woodbine House, 2000, 28.

³Families and Fragile X Syndrome: U.S. Department of Health and Human Services, Public Health Service, National Institutes of Health, National Institute of Child Health and Human Development. 2003

References

¹ American Psychiatric Association. Diagnostic and statistical manual of mental disorders: DSM-IV-TR (fourth edition, text revision). Washington DC: American Psychiatric Association, 2000.

² Filipek PA, Accardo PJ, Baranek GT, Cook Jr. EH, Dawson G, Gordon B, Gravel JS, Johnson CP, Kellen RJ, Levy SE, Minshew NJ, Prizant BM, Rapin I, Rogers SJ, Stone WL, Teplin S, Tuchman RF, Volkmar FR. The screening and diagnosis of autism spectrum disorders. Journal of Autism and Developmental Disorders, 1999; 29(2): 439-484.

³. Yeargin-Allsopp M, Rice C, Karapurkar T, Doernberg N, Boyle C, Murphy C. Prevalence of Autism in a US Metropolitan Area. The Journal of the American Medical Association.. 2003 Jan 1;289(1):49-55.

⁴ Newschaffer CJ (Johns Hopkins Bloomberg School of Public Health). Autism Among Us: Rising Concerns and the Public Health Response [Video on the Internet]. Public Health Training Network, 2003 June 20. Available from: http://www.publichealthgrandrounds.unc.edu/autism/webcast.htm.

⁵ Volkmar FR. Medical Problems, Treatments, and Professionals. In: Powers MD, ed. Children with Autism: A Parent's Guide, Second Edition. Bethesda, MD: Woodbine House, 2000; 73-74.

⁶ Powers MD. What Is Autism? In: Powers MD, ed. Children with Autism: A Parent's Guide, Second Edition. Bethesda, MD: Woodbine House, 2000, 28.

⁷ Smalley SI, Autism and tuberous sclerosis. Journal of Autism and Developmental Disorders, 1998; 28(5): 407-414.

⁸ Filipek PA, Accardo PJ, Ashwal S, Baranek GT, Cook Jr. EH, Dawson G, Gordon B, Gravel JS, Johnson CP, Kallen RJ, Levy SE, Minshew NJ, Ozonoff S, Prizant BM, Rapin I, Rogers SJ, Stone WL, Teplin SW, Tuchman RF, Volkmar FR. Practice parameter: screening and diagnosis of autism. Neurology, 2000; 55: 468-479.

⁹ Baird G, Charman T, Baron-Cohen S, Cox A, Swettenham J, Wheelwright S, Drew A. A screening instrument for autism at 18 months of age: A 6-year follow-up study. Journal of the American Academy of Child and Adolescent Psychiatry, 2000; 39: 694-702.

¹⁰ Robbins DI, Fein D, Barton MI, Green JA. The modified checklist for autism in toddlers: an initial study investigating the early detection of autism and pervasive developmental disorders. Journal of Autism and Developmental Disorders, 2001; 31(2): 149-151.

¹¹ Stone WL, Coonrod EE, Ousley OY. Brief report: screening tool for autism in two-year-olds (STAT): development and preliminary data. Journal of Autism and Developmental Disorders, 2000; 30(6): 607-612.

¹² Berument SK, Rutter M, Lord C, Pickles A, Bailey A. Autism Screening Questionnaire: diagnostic validity. British Journal of Psychiatry, 1999; 175: 444-451.

¹³ Ehlers S, Gillberg C, Wing L. A screening questionnaire for Asperger syndrome and other high-functioning autism spectrum disorders in school age children. Journal of Autism and Developmental Disorders, 1999; 29(2): 129-141.

¹⁴ Garnett MS, Attwood AJ. The Australian scale for Asperger's syndrome. In: Attwood, Tony. Asperger's Syndrome: A Guide for Parents and Professionals. London: Jessica Kingsley Publishers, 1997.

¹⁵ Scott FJ, Baron-Cohen S, Bolton P, Brayne C. The Cast (Childhood Asperger Syndrome Test): preliminary development of a UK screen for mainstream primary-school-age children. Autism, 2002; 2(1): 9-31.

¹⁶ Tadevosyan-Leyfer O, Dowd M, Mankoski R, Winklosky B, Putnam S, McGrath L, Tager-Flusberg H, Folstein SE. A principal components analysis of the autism diagnostic interview-revised. Journal of the American Academy of Child and Adolescent Psychiatry, 2003; 42(7): 864-872.

¹⁷ Lord C, Risi S, Lambrecht L, Cook EH, Leventhal BL, DiLavore PC, Pickles A, Rutter M. The autism diagnostic observation schedule-generic: a standard measure of social and communication deficits associated with the spectrum of autism. Journal of Autism and Developmental Disorders, 2000; 30(3): 205-230.

¹⁸ Van Bourgondien ME, Marcus LM, Schopler E. Comparison of DSM-III-R and childhood autism rating scale diagnoses of autism. Journal of Autism and Developmental Disorders, 1992; 22(4): 493-506.

¹⁹ Department of Health and Human Services. Mental Health: A Report of the Surgeon General. Rockville, MD: Department of Health and Human Services, Substance Abuse and Mental Health Services Administration, Center for Mental Health Services, National Institute of Mental Health, 1999.

²⁰ Lovaas OI. Behavioral treatment and normal educational and intellectual functioning in young autistic children. Journal of Consulting and Clinical Psychology, 1987; 55: 3-9.

²¹ McEachin JJ, Smith T, Lovaas OI. Long-term outcome for children with autism who received early intensive behavioral treatment. American Journal on Mental Retardation, 1993; 97: 359-372.

²² Couper JJ, Sampson AJ. Children with autism deserve evidence-based intervention. Medical Journal of Australia, 2003; 178: 424-425.

²³ American Academy of Pediatrics Committee on Children With Disabilities. The pediatrician's role in the diagnosis and management of autistic spectrum disorder in children. Pediatrics, 2001; 107(5): 1221-1226.

²⁴ Dunlap G, Foxe L. Teaching students with autism. ERIC EC Digest #E582, 1999 October.

²⁵ Autism Society of America. Biomedical and Dietary Treatments (Fact Sheet) [cited 2004], 2003. Bethesda, MD: Autism Society of America. Available from: http://www.autism-society.org/site/PageServer?pagename=BiomedicalDietaryTreatments.

²⁶ McDougle CJ, Stigler KA, Posey DJ. Treatment of aggression in children and adolescents with autism and conduct disorder. Journal of Clinical Psychiatry, 2003; 64 (supplement 4): 16-25.

²⁷ Research Units on Pediatric Psychopharmacology Network. Risperidone in children with autism and serious behavioral problems. New England Journal of Medicine, 2002; 347(5): 314-321.

²⁸ Hviid A, Stellfeld M, Wohlfahrt J, Melbye M. Association between thimerosal-containing vaccine and autism. JAMA, 2003; 290(13): 1763-1766.

²⁹ Akshoomoff N, Pierce K, Courchesne E. The neurobiological basis of autism from a developmental perspective. Development and Psychopathology, 2002; 14: 613-634.

³⁰ Korvatska E, Van de Water J, Anders TF, Gershwin ME. Genetic and immunologic considerations in autism. Neurobiology of Disease, 2002; 9: 107-125.

³¹ Courchesne E. Carper R, Akshoomoff N. Evidence of brain overgrowth in the first year of life in autism. JAMA, 2003; 290(3): 337-344.

This brochure was written by Margaret Strock, Public Information and Communications Branch, NIMH. Scientific information and review were provided by NIMH staff members Stephen Foote, MD; Ann Wagner, Ph.D.; Audrey Thurm, Ph.D.; Benjamin Vitiello, MD; Douglas Meinecke, Ph.D.; and Judith Cooper, Ph.D., National Institute on Deafness and Other Communication Disorders. Editorial assistance was provided by Ruth Dubois and Antoinette Cooper.

NIH Publication No.04-5511
April 2004

Citation for this publication:

Strock, Margaret (2004). Autism Spectrum Disorders (Pervasive Developmental Disorders). NIH Publication No. NIH-04-5511, National Institute of Mental Health, National Institutes of Health, U.S. Department of Health and Human Services, Bethesda, MD, 40 pp. http://www.nimh.nih.gov/publicat/autism.cfm

To order a printed copy, call 1-866-615-NIMH (6464) toll-free. For additional information, please visit the NIMH Web site at: http://www.nimh.nih.gov.

NIMH publications are in the public domain and may be reproduced or copied without the permission from the National Institute of Mental Health (NIMH). NIMH encourages you to reproduce them and use them in your efforts to improve public health. Citation of the National Institute of Mental Health as a source is appreciated. However, using government materials inappropriately can raise legal or ethical concerns, so we ask you to use these guidelines:

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Addendum to Autism Spectrum Disorders February 2007

This addendum to the booklet Autism Spectrum Disorders was prepared to clarify information contained in the booklet; and to provide updated information on the prevalence of autism spectrum disorders.

Prevalence

In 2007 - the most recent government survey on the rate of autism - the Centers for Disease Control (CDC) found that the rate is higher than the rates found from studies conducted in the United States during the 1980s and early 1990s (survey based on data from 2000 and 2002). The CDC survey assigned a diagnosis of autism spectrum disorder based on health and school records of 8 year olds in 14 communities throughout the U.S. Debate continues about whether this represents a true increase in the prevalence of autism. Changes in the criteria used to diagnose autism, along with increased recognition of the disorder by professionals and the public may all be contributing factors. Nonetheless, the CDC report confirms other recent epidemiologic studies documenting that more children are being diagnosed with an ASD than ever before.

Data from an earlier report of the CDC's Atlanta-based program found the rate of autism spectrum disorder was 3.4 per 1,000 for children 3 to 10 years of age. Summarizing this and several other major studies on autism prevalence, CDC estimates that 2–6 per 1,000 (from 1 in 500 to 1 in 150) children have an ASD. The risk is 3-4 times higher in males than females. Compared to the prevalence of other childhood conditions, this rate is lower than the rate of mental retardation (9.7 per 1,000 children), but higher than the rates for cerebral palsy (2.8 per 1,000 children), hearing loss (1.1 per 1,000 children), and vision impairment (0.9 per 1,000 children).¹ The CDC notes that these studies do not provide a national estimate.

For additional data, please visit the autism section of the CDC Web site.

Fragile X

The original booklet and Web page contains the following statement about inheriting Fragile X Syndrome:

"For an unknown reason, if a child with ASD also has Fragile X, there is a one-in-two chance that boys born to the same parents will have the syndrome². Other members of the family who may be contemplating having a child may also wish to be checked for the syndrome."

A distinction can be made between a father’s and mother’s ability to pass along to a daughter or son the altered gene on the X chromosome that is linked to fragile X syndrome. Because both males (XY) and females (XX) have at least one X chromosome, both can pass on the mutated gene to their children.

A father with the altered gene for Fragile X on his X chromosome will only pass that gene on to his daughters. He passes a Y chromosome on to his sons, which doesn’t transmit the condition. Therefore, if the father has the altered gene on his X chromosome, but the mother’s X chromosomes are normal, all of the couple’s daughters would have the altered gene for Fragile X, while none of their sons would have the mutated gene.

Because mothers pass on only X chromosomes to their children, if the mother has the altered gene for Fragile X, she can pass that gene to either her sons or her daughters. If the mother has the mutated gene on one X chromosome and has one normal X chromosome, and the father has no genetic mutations, all the children have a 50-50 chance of inheriting the mutated gene.

The odds noted here apply to each child the parents have.³
In terms of prevalence, the latest statistics are consistent in showing that 5% of people with autism are affected by fragile X and 10% to 15% of those with fragile X show autistic traits.

References for the Addendum

¹Yeargin-Allsopp M, Rice C, Karapurkar T, Doernberg N, Boyle C, Murphy C. Prevalence of Autism in a US Metropolitan Area. The Journal of the American Medical Association. 2003 Jan 1;289(1):49-55.

²Powers MD. What Is Autism? In: Powers MD, ed. Children with Autism: A Parent's Guide, Second Edition. Bethesda, MD: Woodbine House, 2000, 28.

³Families and Fragile X Syndrome: U.S. Department of Health and Human Services, Public Health Service, National Institutes of Health, National Institute of Child Health and Human Development. 2003

If you have questions regarding these guidelines and use of NIMH publications, please contact the NIMH Information Center at 1-866-615-6464 or at nimhinfo@nih.gov.