Autism frequently makes headlines in the news, often highlighted by debate and controversy. Although countless research hours and dollars have been spent studying autism, much remains to be understood about the disorder, including why there has been an uptick in cases, and whether childhood vaccines are to blame.
Autism is one of a group of neurologically-based developmental disabilities called autism spectrum disorders (ASDs), which are conditions that feature substantially impaired social interaction and communication skills and unusual behaviors and interests. Other ASDs include Asperger syndrome, Rett syndrome, childhood disintegrative disorder and pervasive developmental disorder not otherwise specified (PDD-NOS).
Boys are four times more likely than girls to have ASDs, which occur in all racial, ethnic and socioeconomic groups, according to the Centers for Disease Control and Prevention (CDC). The effects of ASDs vary widely, from mild to disabling. Some people diagnosed as being "on the spectrum" avoid social situations, miss verbal and non-verbal social cues and come across as odd or eccentric, but live successfully and independently, while others with an ASD might exhibit repetitive or self-injurious behaviors and entirely lack communicative language. The intellectual capacity of people with ASDs varies as well, from individuals who are gifted to those who are severely challenged.
The number of autistic children has grown 10-17 percent per year during the past decade, with current estimates predicting that 1 in 150 children in the United States will be diagnosed as having an ASD, according to the CDC. In New Hampshire, school records (the only current means of tracking) show a substantial increase, from 397 cases in 2000 to 1,060 in 2006.
The varying levels of symptoms that are associated with ASDs, along with an increased awareness of ASDs and changing diagnostic criteria, have led some people to question the rising incidence rates. As rates of autism have gone up, diagnoses of mental retardation have gone down. Has awareness or perhaps a broader definition of autism led to an apparent incidence increase? No one knows for sure, but many experts agree that awareness and revised diagnostic criteria alone do not account for the growing number of autism cases.
There is also uncertainty surrounding possible causes of autism. An emotional maelstrom continues to swirl around the idea that thimerosal, a mercury-based preservative used in children's vaccines, causes autism. Scientific studies have refuted the idea that vaccinations directly cause autism, and the federal government has worked to eliminate thimerosal from childhood vaccines, but some people still cling to the idea that vaccinations put children at risk.
It can be difficult to dismiss the argument that vaccinations are somehow linked to autism when faced with heart-wrenching stories from parents, says Dr. Arthur C. Maerlender Jr., a neuropsychologist at Dartmouth-Hitchcock Medical Center and assistant professor in Psychiatry at Dartmouth Medical School. "When you talk to parents whose child is clearly autistic, and they say [the autism symptoms] started within a month of having - or within days, they sometimes tell me - of their child having the shot, it's kind of hard to say, 'Well, you don't know what you're talking about.' ... You get these anecdotal stories that are very compelling and you think, boy, it sure sounds like that could be true, but the research doesn't support it."
Symptoms associated with autism appear before a child reaches his or her third birthday, which is around the same time that children routinely make consistent visits to their pediatrician and receive vaccinations, points out Dr. Laura Rubin, a clinical psychologist and founder of the Portsmouth Neuropsychology Center. So maybe it's possible that the relationship between vaccines and autism is more coincidental than causal, some say - just a matter of timing.
The debate goes on. Some people believe that any of a number of toxins in our environment and in our food has contributed to the spike in autism cases. Still others point solely to genetics; Harvard researchers this summer identified six genes involved in autism. Many scientists believe the truth lies somewhere in between, and that autism results from a combination of environmental factors and genetics.
Scientists do know that if a child has a certain set of genetic preconditions, and then particular environmental conditions occur, such as a toxic substance entering the child's body or environment, a certain outcome can be triggered, says Maerlender. But there are many steps along the way, and there is much genetic variation among individuals. "You don't just go from genes to behavior," he says. "There are quite a few things that happen in the middle, and that's what makes it subtle and very complex and difficult to tease out."
With early intervention and treatment, autism symptoms can substantially improve, but as with ASDs themselves, results vary. "In general, autism spectrum disorders are a life-long disability," says Rubin. "However, with appropriate intervention that is intensive and provided by trained professionals, you can show remarkable gains in language, behavior and social skills."
Experts emphasize that the earlier treatment begins, the better. Autism can usually be reliably diagnosed by the time a child is 18-24 months of age, but the mean age of diagnosis is 38 months, Rubin says. "That's problematic, given the importance of intervening early," she says.
Intervention strategies are usually multi-faceted, Rubin says. Treatment often includes modifying behavior, teaching relatedness and focusing on development of social and language skills, sometimes in combination with medication to handle ASD symptoms, such as hyperactivity.
Unfortunately, low-functioning people on the spectrum typically face an uncertain future, one that does not involve marriage and a career, but a life of dependence on family and caregivers. Impaired learning capability, limited language usage and extreme, repetitive behaviors can make management of these individuals very difficult.
Some of the higher functioning individuals diagnosed with an ASD do relatively well in their interpersonal relationships and have desirable qualities and talents that they can put to good use in their personal life and careers, Maerlender says.
Some areas of medicine can provide productive careers for intellectually bright and high-functioning individuals with an ASD, although their bedside manner might be somewhat stiff, Maerlender says. And the computer industry is another likely career choice for high-functioning people on the spectrum, who might find comfort in the lack of human contact required in many computer-related jobs and the ability to live much of life online. They also tend to like the linear thinking that goes along with computers.
Many have a knack for rote learning and memorization, although they do poorly in new or novel situations. As a result, they can often excel at acting. "It's almost like they can put on another persona, another face. I interpret it as, they know what the expectations are, how they're supposed to act. They love it and they're great at it," says Maerlender. NH
This article appears in the October 2009 issue of New Hampshire Magazine