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In the past four years, diagnoses of autism have nearly doubled nationwide, making this once-rare disorder one of the most prevalent conditions, more common than childhood cancer, diabetes and Down Syndrome. Autism is a lifelong neurological disorder whose symptoms include little or no eye contact, lack of responsiveness to speech, repetitive and stereotyped motor movements. Though it is widely described as a spectrum of disorders - ranging in symptoms from mild to severe and more common in males than in females - autism always bears one universal feature: social impairment. Now, a new study released in April by the California Department of Developmental Services reports a dramatic and unexplained increase of autism in children throughout the state. According to the study, the number of autistic children in California increased from 10,360 in 1998 to 20,377 in 2002, confirming a trend first reported in a similar study published by the state in 1999. That one showed a 237 percent increase in autism diagnoses over the previous 12 years. Since 1987, the total population of California children diagnosed with autism has increased by 634 percent. And there is no sign of lessening: Between January and April of this year, another 832 children have been added to the caseload, at a rate of nearly 10 new cases a day. Because the term "autism" encompasses such a wide spectrum, this latest study was careful to exclude Asperger syndrome and pervasive developmental disorder, conditions that exist on the ends of the spectrum. Though it also excluded children under three, it observed that the average age of children entering the healthcare system has shifted steadily downward: "As more young children with autism reach late adolescence and adulthood," it said, "the need for out-of-home residential services will increase and have a substantial impact on the Department's budget." Hower Kwon, MD, a child psychiatrist at Lucile Packard Children's Hospital and senior research scientist at Stanford University School of Medicine, specializes in the field of autism and is engaged in a variety of functional and structural brain analysis studies. Here, he discusses the state's epidemiological study and what it signifies for parents and children. Question / Answer Quick Links:
Question: It wasn't so long ago that you'd hear parents of autistic children complain bitterly that their pediatricians had repeatedly dismissed their early concerns. `Oh, he's a boy. Boys always talk later,' they'd say. Which meant that many autistic children weren't diagnosed until it was too late to do anything. Has that been changing? Kwon: We think so, because a lot of the referrals now come from pediatricians. We are still hearing some of those stories and they're unfortunate stories but we're hearing them less and less. Q: Are you seeing any changes here at the developmental disorders clinic at Lucile Packard Children's Hospital? Kwon: I think overall there is a much greater awareness, and I do think that leads to a greater likelihood of diagnosis. Clinicians are more cognizant of the diagnosis. In our clinic, the age of children coming in for a first evaluation has gotten younger and younger. We now routinely see children between the ages of two and three. Kids who are picked up early on are the ones most likely to benefit from intensive interventions. We feel there is an urgency to see them as early as possible. Q: What percentage of children who receive an evaluation leave with a positive diagnosis? Kwon: On the autism spectrum, I'd estimate 70 to 80 percent. Q: So they are being appropriately referred? Kwon: Yes, we think so. We think that more and more people are becoming sensitive to the significant symptoms and signs that may be associated with autism. The biggest concern that parents come here with is language delay, followed by impaired socialization and a variety of other behavioral issues. Kwon: We think about language milestones, starting with words at about one year; and then using phrases and putting words together by age two. Even before one year, we would expect to hear children trying to imitate sounds: mama, dada … And then social interactions: smiling spontaneously, which they should be able to do very early on, within a matter of months. By the first year, certainly by a year-and-a- half, they should be able to play imitative social games like patty-cake or peekaboo. Pointing is another important skill - both to communicate and as a social function that allows them to get what they want. Part of pointing involves not just pointing at the object but also looking at the parent to see if the parent is actually paying attention. Q: Since all these behaviors arise in the first year or two, does it make sense for a parent to wait until their child is two or three before getting him evaluated? Kwon: We are probably going to see children in our clinic who are younger and younger, whose parents are more educated about these conditions. And there may be a balancing point, prior to which we are not going to be able to make a correct diagnosis of autism. At 1 year of age, we really cannot say a lot about their language or their ability to socialize except in the simplest of ways. But by 3, though, we have a pretty good idea. As you see younger and younger children, it's going to get harder and harder to discern whether it's just some normal variation in development or whether it's something quite out of the ordinary. That balancing point probably falls somewhere between one to two years. Q: There's widespread agreement that early intervention is crucial for treatment of autism, yet it's been estimated that fewer than 10 percent of kids ever get it. Kwon: We often prescribe intensive early intervention, such as discrete trials therapy, because it's the best treatment we have to date for young children severely affected with autism. It is very intensive, one-on-one therapy, but it is the only system of treatment that’s been shown to be significantly effective in these cases. At this time, the medications available to us really don't address any of the underlying issues of autism. And none of the other forms of alternative therapy, including secretin (a digestive hormone), dietary changes, or megavitamins, have panned out. Q: Why is early intervention so unavailable? Kwon: Because it is so expensive and so labor intensive and also because there are not enough people who are trained to administer these treatments - even when parents are willing to pay for them. So parents often become trained themselves. Q: It's been suggested that life-saving obstetric care and neonatal intensive care may be driving up the numbers, since families with a strong genetic predisposition to autism may have higher complications during birth and pregnancy. What do you think of that? Kwon: I think theoretically that's a possibility, because we know that children who have developmental delays as a result of prematurity may have symptoms that are very similar to those seen in autism. The problem is that a lot of children may have mental retardation as a result of prematurity, and with more severe MR, it becomes more difficult to parcel out what symptomatically is the result of MR and what is the result of autism. The two blend into each other, and it becomes harder to discern the differences as these conditions become more severe. So when we see children with lower cognitive functioning, we frequently see symptoms that are consistent with autism - repetitive behaviors, decreased flexibility, increased rigidity, stereotyped motor movements, and certainly language delays. Q: Some parents are convinced that their child's autism is the result of vaccination. It's been suggested, for instance, that the mercury in the MMR (measles, mumps, rubella) vaccine may be at fault. What are the risks? Q: Can you describe the difference between autism spectrum disorder and pervasive developmental disorder? Kwon: Those phrases are really interchangeable. Most of us in the field are working with the notion that these conditions fall on a spectrum. So you can have kids with autism who are very mentally retarded, who have extremely limited verbal skills and no desire to have social contact with anyone. On the other end of the spectrum, you have kids who have social impairment but normal or very high IQs. I think one of the more interesting questions in the field is whether there's a difference between high functioning autism and Asperger's disorder. If there is significant language delay we say that the child has autism instead of Asperger, but we often see children with high-functioning autism who go on to develop language and look indistinguishable from children diagnosed with Asperger. Q: Do children with Asperger syndrome typically have excellent language skills. Kwon: You may see aspects of language that are quite good - vocabulary, sentence formation, reading skills. But they still have subtle language problems and some not so subtle language problems. A lot of children with Asperger do in fact have trouble with sustaining conversation; they have difficulty in using language in a socially appropriate manner. They monopolize conversation or may have trouble reciprocating appropriately during the course of a conversation. Kwon: We've found larger cerebral volume in children with autism as compared to a control group. We did not find it in children with Asperger’s disorder. We also found that children with autism and Asperger appear to process cognitive functions differently from children without the conditions. Q: Is that consistent with other findings - that autistic children undergo faster brain development than normal children? And that their actual head sizes are bigger? Kwon: That's been looked at in previous research. At birth, they did not seem to be clinically bigger - what we call macrocephaly. But by two or three years of age, they became macrocephalic. So it appears that between birth and two to three years, some abnormal process of brain development occurred. I wouldn't say their brains develop more rapidly. Instead, it appears that the nature of brain development in children with autism is different. Along with a different rate of growth early on, individuals with autism appear to have different patterns of gray and white matter changes during the first two decades. It's clearly an abnormal trajectory of development, with bigger not necessarily translating to better in the case of autism. Kwon: Certainly, it’s an important question to address. Clinicians felt they were seeing more and more kids with autism and related conditions and the question was whether this would be borne out with actual numbers from the Regional Centers and not just by clinicians' isolated impressions. What this study shows is that when they did a retrospective analysis of a group of children back in the 1980s and then of another in the 1990s, the rate of children accurately diagnosed with autism was pretty consistent. About 85 percent to 90 percent of the kids who were given the diagnosis of autism met DSM-IV criteria, the most recent set of criteria available. So the increase was not because of the use of different criteria for autism. Q: Is there any reason to suspect that these numbers are unique to California? Lucile Packard Children's Hospital is located in Palo Alto, adjacent to Stanford University Hospital, approximately 20 miles north of San Jose, CA and 40 miles south of San Francisco.
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