Mentally challenged and Autistic children

Since the 1990s, there’s been a dramatic increase in autism (search) among school-age children. The data are from the U.S. Department of Education, and the report hints that the increases seen with time are real.

Research has suggested that the rise in autism could be largely explained by changes in diagnosis, with children who might have been classified as mentally retarded or speech impaired before the 1990s now being classified as autistic. Lead researcher Craig J. Newschaffer, PhD, says the Department of Education figures do not show this, but he adds that the increase in autism may never be fully understood.

“I don’t know if we are ever going to be in a position to explain what has gone on over the last decade,” he says. “The hope is that with the surveillance programs that are now in place we will be in a better position to understand future trends.” Earlier findings from the CDC and others have suggested as much as a tenfold increase in autism and related disorders during the last decade of the 20th century.

The study does not answer the question as to why autism is increasing. But the national data don’t show a decrease in other learning disabilities. Trends for mental retardation (search) and speech and language impairment remained unchanged. This suggests the increase in autism is not the result of an across-the-board increase in special education classification, say the researchers.

Trend May Be Leveling Off
Newschaffer and colleagues from an autism tracking center at the Johns Hopkins Bloomberg School of Public Health analyzed national special education data collected from 1992 to 2001. The findings are reported in the March issue of the journal Pediatrics. The research offers intriguing early evidence that the upward trend in autism cases may be beginning to level off. But Newschaffer cautions that the finding may be misleading.

He says a change in 1997 that allowed children up to the age of 9 to be classified as “developmentally delayed” may explain the apparent leveling of autism cases. Before 1997 the diagnosis was used only for children 5 and under. It is possible, Newschaffer explains, that children with this label who would have been reclassified as autistic after age 5 are now being diagnosed when they are older.

“We will need a few more years of data to determine if the rise in autism is really leveling off,” he says.

Early Diagnosis Is Key
The most recent figures indicate that as many as one in 166 children in the U.S. is autistic or has an autism-related disorder, such as Asperger syndrome. Despite a growing awareness of the importance of early diagnosis, the new report suggests that many children are still being diagnosed at older ages.

Last month, the CDC launched a major public health initiative to promote early diagnosis by raising awareness about child development milestones. “By recognizing the signs of developmental disabilities early, parents can seek effective treatments which can dramatically improve their child’s future,” CDC Director Julie Gerberding, MD, says in a news release.

The focus of the campaign is to get parents to keep track of important developmental milestones such as when their child learns to smile, when they recognize the word “no,” when they learn to speak and play, and how they interact with others. Pediatrician and epidemiologist Marshalyn Yeargin-Allsopp, MD, says the hope is that parents will learn to identify developmental delays as early as possible. Yeargin-Allsopp is conducting an ongoing study of autism prevalence trends for the CDC.

“Parents need to know the signs and bring those signs to the attention of their health care provider,” she says. “After all, parents know their children better than anyone. And providers can’t take a ‘wait-and-see’ attitude. They have to refer a child quickly for diagnostic assessment even if they just suspect a developmental delay so that a child can get intervention services as early as possible, if necessary.”

Early Signs of Autism Identified in Infants

Findings Could Lead to More Effective Treatment. Canadian researchers say they can recognize the early signs of autism in children as young as 6 months old, and they hope their findings will lead to better early treatments for the disorder.

In their ongoing study that now includes autism centers across 14 cities in Canada and the U.S., the researchers are following the progression of younger siblings of children with autism.

According to the National Alliance for Autism Research, a child born into a family in which an older child has been diagnosed with autism is 50 times more likely to develop the disorder than a child with no afflicted siblings.

In this study, researchers show that by age 1, siblings who are later diagnosed with autism may be distinguished from other siblings by early developmental behaviors.

“This is groundbreaking work that is pushing the frontier of what we know about the biological nature of autism, and why it emerges so early in life,” says researcher Lonnie Zwaigenbaum, MD, of Ontario’s McMaster University. “Our hope is that it will lead to the development of new and earlier treatments that could make a huge difference for these children.”
High-Risk Kids Followed From Birth

Autism is typically diagnosed in children around the age of 2 or 3 years, but parents often have concerns about developmental delays much earlier. There is strong evidence that autism has its origin in abnormal brain development early in prenatal life, write the authors.

In an effort to better understand the early signs of autism, Zwaigenbaum and colleagues have been observing more than 200 younger siblings of children with autism, many of whom have been followed from birth.

They developed a 16-point observational checklist called the Autism Observational Scale designed to map the development of infants as young as 6 months.

Specific markers include making infrequent eye contact, not smiling in response to smiles from others, and, in older children, exhibiting delayed language skills.

Even as early as 6 months of age, the researchers found that certain behaviors tended to distinguish siblings later diagnosed with autism from siblings who developed normally. These behaviors included passivity and a decreased activity level at 6 months of age, followed by extreme irritability, a tendency to fixate on objects, reduced social interaction, and lack of facial expression.

At 1 year, these same children also tended to have difficulty with language and communication, and they used fewer gestures. Zwaigenbaum noted that almost all of the children in the study who were diagnosed with autism by age 24 months had seven or more of these markers by the time they were a year old.

The findings are reported in the latest issue of the International Journal of Developmental Neuroscience. While the checklist may be useful for recognizing signs of autism in very high-risk children like the ones in the study, its relevance as an observational tool for other children is not yet known.