Autism has increased rapidly in the United States since the late 1980s, and the increase is occurring at varying rates in different areas of the country, leading some scientists to suspect environmental factors. Autism cases diagnosed in California more than doubled between 1987 and 1998 while they increased 10-fold in Atlanta from 1986 to 1996. Some experts say at least some of the increase can be attributed to inconsistencies in reporting and changing criteria for diagnosis. 
[SOURCE: Diana Parsell, "Assault on Autism: Scientists Target Drugs and Other Environmental Agents That May Play a Role," Science News, November 13, 2004] [SOURCE: "New Hope for IBS," Better Nutrition, January, 2005]

Mothers of autistic children were more likely than other mothers to have suffered from asthma or allergic disorders, according to a controlled study of 2,500 children. About 16 percent of the mothers of autistic children-but only 11 percent of mothers in the control group-had asthma during the five-year period surrounding their pregnancies. About 25 percent of the mothers of autistic children-but 18 percent of controls-had an allergic disease during the same period. Researchers believe the link could be due to the immune response of the mother during pregnancy, which could cross the placenta and disrupt the development of the child's neurological system. Another explanation could be that autism shares environmental risk factors with asthma and allergic disorders. 
[SOURCE: Kerri Wachter, "Autism May Be Linked to Maternal Asthma,

A small pilot study found that high functioning autistic fourth graders benefitted from individualized, one-on-one sessions helping them learn to initiate relationships and respond socially to their classmates. By definition, a high functioning autistic individual has an IQ greater than 70. While they are able to function in regular classrooms, those in the study had fewer friends and poorer quality friendships. After the individualized intervention, focusing on greetings and maintaining conversation, these students "went from being peripheral to peer networks to being a nuclear member of them," the researchers noted. 
[SOURCE: Jeff Evans, "Study on High-Functioning Autism Underway," Clinical Psychiatry News, October, 2004]