April 4, 2011 -- For children diagnosed with autism, hope comes in many forms -- stimulants, hormone therapy, vitamins, powerful antipsychotic medications, intensive behavioral therapies, and strict diets.
It is harder, however, to find treatments that have been scientifically proven to help.
Now three government-funded studies, published in the journal Pediatrics, have examined the evidence behind common medical and behavioral treatments for autism spectrum disorders (ASDs). They concluded that there’s little proof that some therapies actually work. And although some medications may ease disruptive and aggressive behaviors, they can have significant side effects.
“I think we are making slow progress,” says Lynne C. Huffman, MD a developmental-behavioral pediatrician and associate professor in the Center for Health Policy at the Stanford University School of Medicine.
“It’s like treating the cough in the child who has pneumonia, if you don’t know what’s causing the pneumonia,” Huffman says. She recently published a similar but separate review of medical and complementary and alternative treatments for autism. She was not involved in the current research.
Part of the reason there’s so little consistent evidence about what works for treating autism, Huffman says, has to do with how variable the symptoms can be.
“Given that, we have this very heterogeneous group of kids who have this great big range in terms of how impairing their symptoms are, and we’ve got some medications that have been pretty well studied and show some effect in some targeted areas,” she says.
What the Studies Found
An interdisciplinary team of researchers from Vanderbilt University, funded by the U.S. Agency for Healthcare Research and Quality, reviewed the evidence behind three types of treatment currently used for children with autism: drugs, intensive behavioral therapies, and injections of the hormone secretin.
“The most important finding from the reviews that were conducted is that there’s still a lot of work to be done to understand how specific treatments affect specific children so that we can tailor recommendations to maximizing improvements and gains,” says Zachary Warren, PhD, director of the treatment and research institute for autism spectrum disorders at Vanderbilt’s Kennedy Center in Nashville.
All of the studies included in the reviews had been published between 2000 and May 2010 and included children 12 or younger.
In the study that looked at medications, researchers reviewed studies of antipsychotics, serum serotonin reuptake inhibitors (SSRIs), and stimulant medications, which are generally used to decrease symptoms like aggression, repetitive behaviors, self-injury, and severe tantrums.
They found good evidence that two antipsychotic drugs, Risperdal and Abilify, decreased “challenging” behaviors like irritability, agitation, crying, hyperactivity, and noncompliance, compared to placebos.
But there were significant side effects reported with the use of these medications, including weight gain, drowsiness, and symptoms such as tremors, involuntary movements, and rigidity.
Though trials of the SSRI Prozac and the stimulant Ritalin showed potential positive effects on repetitive behaviors and hyperactivity, the reviewers declared current evidence to be insufficient to recommend their use.
Early Intensive Behavioral Interventions
Intensive behavioral therapies, where a therapist or parent works one on one with an autistic child for more than 25 hours a week over several years, have made recent headlines as studies have shown that these approaches may yield substantial improvements in IQ, language, and interpersonal skills.
But when reviewers sat down to compare apples to apples in this range of different approaches, they found themselves looking at mixed fruit.
“When you start talking about interventions that are primarily behavioral or educational in nature that are delivered for many hours a week over the course of a year or two, there are so many factors that need to be brought into that comparison that it is very tricky,” Warren says.
“What we do see is a body of work that suggests that yes, in fact, young children with autism spectrum disorders who do receive early intensive intervention do show or tend to show benefit,” he says, “But there are some who show much more benefit than others. And there are some interventions where the effects are very modest, and some subgroups are showing tremendous gains.”
Researchers looked at three broad categories of therapies. The first was the so-called University of California at Los Angeles/Lovaas approach, where therapists work with children at least 25 hours a week to try to combat specific behaviors and deficits associated autism.
For example, if an autistic child shows interest in a toy, but not necessarily a person in the same room, a therapist might hold the toy and prompt the child to ask for it in an appropriate way, in an effort to develop communication skills.
The second category of interventions included programs that attempt to address autistic tendencies in very young children, who are under 2 years of age. In general, these are studies based on the Early Start Denver Model, which uses play-based therapy to encourage language and social skills.
The third kind of therapies reviewed were programs that train parents to help their kids at home.
“The mantra in the field has been that with early identification and early intervention, you can improve the long-term developmental trajectory of the illness,” says Eric Hollander, MD, director of the Compulsive, Impulsive and Autism Spectrum Disorders Program at Montefiore Medical Center in New York City.
Among 23 studies of the UCLA/Lovaas method and four studies of the Denver Early Start program that were included in the review, many showed gains in IQ, cognitive performance, language skills, and adaptive behaviors.
But those findings appeared to be biased from the get-go, experts say, because children who got the intensive interventions, as opposed to “eclectic” community-based programs, started out with milder symptoms.
“The early studies were flawed,” Hollander says. He was not involved in the reviews.
“There are some kids who get response to some treatments over a short period of time, but it’s kind of hard to figure out which of the kids respond best to which specific treatments and whether those treatments have a large impact over time,” he says.
It’s a critical question, too, considering what it costs to provide these therapies.
“There are high costs associated with these treatments, hundreds of thousands of dollars a year,” Hollander says.
Reviewers cited a lack of high-quality studies and a lack of confirmatory research, or studies that independently duplicate previous findings, as a reason to further question these approaches. They noted that one finding that was “powerfully replicated” across studies was that many kids who get these therapies “will not demonstrate dramatic gains ... .”
Among seven studies of parent-training programs, researchers said small sizes, failure to randomly assign participants to different treatments, wide variation in the symptoms of children enrolled in the studies, and a lack of objectively assessed outcomes limited the conclusions that could be drawn.
The final review looked at evidence behind the use of controversial therapy of the gut protein secretin.
Out of 4,120 studies considered, only eight met criteria for inclusion in the review.
When secretin was compared to a placebo, no studies have shown improvements in measures of language, cognition, or autistic symptoms.
“That’s one of the interventions that have the most powerful evidence,” Warren says, “and the evidence really powerfully suggests that this is something that should not be pursued.”
Hope on the Horizon
Hollander and Warren say although current therapies appear to offer little in the way of help, a new generation of medications in development aim to ease symptoms by targeting the underlying causes of the disease, not just the symptoms.
“We’re on the verge of an era of being able to think about being able to develop new, targeted treatments based on an understanding about what we know about autism and how autism is related to our brain,” Warren says. “In animal models, they’ve been able to demonstrate recovery of certain symptoms and certain behaviors.”
And many experts feel that with better designed studies, at-home behavioral training, where a therapist educates parents about ways to find opportunities to practice communication skills, will ultimate show great benefits.
“Parent training approaches, where parents learn to find teachable moments with their child, that’s a very powerful thing,” says Byrna Siegel, PhD, director of clinical services at the University of California at San Francisco’s Autism Clinic.
“I tell people that there’s a lot of stuff you can do to help your kid, but it involves a lot of hard work,” she says.