News and Notes about Scientific Research on Autism and other Developmental and Behavioral Disorders

Editor: Gina Green, PhD, BCBA
Director of Research, New England Center for Children

New Studies Find No Evidence of Link Between MMR Vaccine and Autism or an Autism “Epidemic”


A theory that the measles, mumps, and rubella (MMR) vaccine causes autism and related disorders has received widespread publicity in recent months. This unproven theory has been tied to a related unproven theory that there is an “epidemic” of autism; that is, many believe that MMR vaccinations are responsible for a large increase in the occurrence of autism. Understandably, these speculations have generated alarm among parents, to the point that many have not been having their young children immunized. This in turn has alarmed many people in the medical and public health communities, because the negative effects of exposure to measles, mumps, and rubella on young children and pregnant mothers are serious and well-documented.

The theory that the MMR vaccine causes autism seems to have originated with a 1998 report by British physician Andrew Wakefield and his colleagues. Based on their evaluations of 12 children, they speculated that MMR vaccination led to inflammatory bowel disease, which in turn led to autistic “regression.” Their study was not controlled, and their conclusions were based largely on anecdotal reports. Subsequent scientific studies failed to confirm an association between bowel problems and autism (Fombonne, 1998, The Lancet, 351, 955; Peltola et al., 1998, The Lancet, 351, 1327). Several recent studies revealed no link between MMR vaccination and the occurrence of autism. For example, two sets of investigators analyzed the immunization records of children diagnosed with autism since 1979 in England, where universal MMR immunization was introduced in 1988. They found no significant differences between the rate with which autism was diagnosed before and after MMR immunization began (Kay et al., February 2001, British Medical Journal; Taylor et al., 1999, The Lancet, 353, 2026-2029). Scientists in Finland recently reported data from extensive monitoring of the MMR vaccination program in that country from 1982 through 1996. Over that 14-year period, almost 3 million doses of the MMR vaccine were given to 1.8 million people. A total of 173 serious adverse reactions were reported, but 45% of them turned out to be due to other factors, such as identified illnesses. The incidence of serious adverse events therefore was 3.2 per 100,000 vaccine doses. Not a single case of autism or inflammatory bowel disease was reported. Over the 14-year period, the vaccination program eliminated congenital rubella as well as acquired measles, mumps, and rubella, and reduced cases of encephalitis by one-third (Patja et al., 2000, Pediatric Infectious Disease Journal, 19, 1127-1134). Researchers in California recently found no correlation between MMR immunization rates and numbers of cases of autism reported to the state Department of Developmental Services between 1980 and 1994 (Dales et al., 2001, Journal of the American Medical Association, 285, 1183-1185). Further research is being conducted, but the scientific evidence to date does not support the theory that the MMR vaccine causes autism; rather, the age at which vaccination typically occurs coincides with the age at which some children begin to exhibit the characteristics of autism.


Widespread speculation that there is an autism “epidemic” also remains unsubstantiated by sound research. Much of the speculation stems from a 1999 report that the California Department of Developmental Services (DDS) saw a huge increase in the number of reported cases of autism between 1987 and 1998. Scientific analyses of that report and epidemiological studies of autism suggest that the reported increase is likely due, not to an actual “epidemic” of autism, but to several other factors: (a) a broadening of the criteria for identifying children as falling on the autism “spectrum” with the introduction of the pervasive developmental disorders diagnostic category a few years ago; (b) improved diagnostic practices; (c) earlier diagnosis; (d) increased public awareness of autism; (e) changes in the reporting practices of special education and human service agencies; and (f) population growth in California over the period of time covered by the DDS report (Fombonne, February 2001, Pediatrics; Jacobson, Science in Autism Treatment, 2 (1), 8-9; Kaye et al., February 2001, British Medical Journal).

Secretin Proves Ineffective for Treating Autism

Starting in 1998, anecdotal reports began appearing on TV, on the Internet, in self-published newsletters and books, and in one medical journal that a single dose of the peptide hormone secretin produced large improvements in behavior and language skills in several children with autism. Secretin, which stimulates pancreatic secretions, was even touted as a “cure” for autism. Thousands of children with autism began receiving secretin injections, often without careful monitoring and at substantial cost to families. At that time, secretin had been approved by the Food and Drug Administration only for single-dose administrations to test pancreatic functioning in adults; its safety for children was unknown. Subsequently, several double-blind controlled studies using objective measures found that secretin produced no clinically meaningful improvements in people with autism over a placebo effect. They include:

Chez, M.G., Buchanan, C.P., Bagan, B.T., Hammer, M.S., McCarthy, K.S., Ovrutskaya, I., Nowinski, C.V., & Cohen, Z.S. (2000). Secretin and autism: A two-part clinical investigation. Journal of Autism and Developmental Disorders, 30, 87-94.

Dunn-Geier, J., Ho, H.H., Auersperg, E., Doyle, D., Eaves, L., Matsuba, C., Orrbine, E., Pham, B., & Whiting, S. (2000). Effects of secretin on children with autism: A randomized controlled trial. Developmental Medicine & Child Neurology, 42, 796-802.

Sandler, A.D., Sutton, K.A., DeWeese, J., Girardi, M.A., Sheppard, V., & Bodfish, J.W. (1999). Lack of benefit of a single dose of synthetic human secretin in the treatment of autism and pervasive developmental disorder. The New England Journal of Medicine, 341, 1801-1806

Research at The New England Center


From time to time, we highlight some of the research that is being conducted at the New England Center for Children. Here is a synopsis of a series of studies on choice-making with students with severe learning difficulties. – Ed.

A good deal of research at the New England Center for Children focuses on techniques for teaching new skills, enhancing engagement in meaningful activities, and decreasing challenging behavior. One area of recent interest is choice behavior – assessing the choices or preferences of students with severe learning difficulties, teaching them to make meaningful choices, and providing them with many opportunities to make choices. Studies conducted by a number of NECC staff have shown that providing choice-making opportunities can have several benefits for students. For example, we found that when students were allowed to choose activities or reinforcers, they were more likely to remain on task and less likely to engage in challenging behavior than when adults made choices for them (e.g., Graff & Libby, 1994, 1995; Graff, Libby, & Green, 1998). Of course, there are times when a student’s choices are limited, or it is very important for him to do certain things at certain times, such as washing his hands and face and brushing his teeth before going to bed. Through systematic research we have found that even in those situations, students can be provided with some choices, and that can have beneficial effects. One study showed that when students selected sequences of activities themselves, they were more likely to complete the activities than when an adult told them to do the activities in a certain order, and they exhibited less challenging behavior (Wehmann, & Graff, 1999). In other studies, allowing students to select reinforcers for completing specific activities enhanced task performance and decreased challenging behavior, regardless of the activities involved (Geckeler, Libby, Ahearn, & Graff, 1998; Geckeler, Libby, & Graff, 1997; Geckeler, Libby, Graff, & Ahearn, 2000; Graff & Libby, 1998; Graff & Libby, 1999; Rice, Graff, & Libby, 1995). In sum, providing choice-making opportunities in a variety of situations has proven to be a relatively simple intervention that has multiple benefits for students with severe learning difficulties.

References
Geckeler, A., Libby, M. E., Ahearn, W. H., & Graff, R. B. (1998, May). Measuring preference for participant-selected versus experimenter-varied stimuli using a concurrent chains procedure. In B. Ahearn (Chair), Participant preference in situations of choice. Symposium presented at the annual meeting of the Association for Behavior Analysis, Orlando, FL.

Geckeler, A., Libby, M. E., & Graff, R. B. (1997, May). The effect of subject-selected versus experimenter-varied reinforcer delivery on response rate. Poster presented at the annual meeting of the Association for Behavior Analysis, Chicago.

Geckeler, A., Libby, M. E., Graff, R. B., & Ahearn, W. H. (2000). Effects of reinforcer choice measured in single and concurrent operants procedures. Journal of Applied Behavior Analysis, 33, 347-351.

Graff, R. B., & Libby, M. E. (1998, May). Single and concurrent operant measures of the effects of pre-session versus within-session choice of reinforcer. In B. Ahearn (Chair), Participant preference in situations of choice. Symposium presented at the annual meeting of the Association for Behavior Analysis, Orlando, FL.

Graff, R. B., & Libby, M. E. (1999). A comparison of presession and within-session reinforcement choice. Journal of Applied Behavior Analysis, 32, 161-173.

Graff, R. B., Libby, M. E., & Green, G. (1998). The effects of reinforcer choice on rates of challenging behavior and free operant responding in individuals with severe disabilities. Behavioral Interventions, 13, 249-268.

Rice, B., Graff, R. B., & Libby, M. E. (1995, May). Student-selected, experimenter-selected, or constant reinforcers: Effects on task performance. In M. Libby (Chair), Measuring choice and its effects on individuals with severe disabilities. Symposium presented at the annual meeting of the Association for Behavior Analysis, Washington.

Wehmann, B., & Graff, R. B. (1999, October). The effects of choice of task sequence on responding. Poster presented at the annual meeting of the Berkshire Association for Behavior Analysis and Therapy, Amherst, MA.

NECC Staff Research Project Garners Recognition

Jackie McCann and Colleen O'Leary of the New England Center's Speech-Language Department recently completed a single-subject study to fulfill a requirement for their class on Research in Communication Disorders at Worcester State College. Their study on "The effects of oral motor exercises on articulation" is one of two recognized by the Worcester State Communication Disorders Department for "most independent research, best design, and most significant implications for the area of communication disorders." Colleen and Jackie presented their study to members of the College on May 1.

Web Resources

For information about immunization and autism, see the websites of the Centers for
Disease Control (www.cdc.gov/nip/vacsafe/concerns/autism) and the National Institute for Child Health and Human Development (www.nichd.nih.gov/publications/pubs/autism2.htm).

For information about autism, visit the National Library of Medicine’s autism site www.nlm.nih.gov/medlineplus/autism.html.


For information about the national certification program for applied behavior analysts, go to the website of the Behavior Analyst Certification Board at www.BACB.com.

For information about applied behavior analysis in the treatment for autism visit www.behavior.org.

For science-based information on biomedical treatments and theories in autism visit www.autism-biomed.org.

For professionally screened information on health care (including some treatments for autism and other developmental disabilities), visit www.quackwatch.com.

Drkoop.com, the website of the former U.S. Surgeon General and the American Council on Science and Health, provides information about scientific research on health care for the general public. NECC Director of Research, Dr. Gina Green, recently published an invited editorial there entitled “Autism and ‘Voodoo Science’ Treatments.” Read it at www.drkoop.com/news/focus/2001/jan/06_autism.html



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