Changes to the Definition of Autism May Help Uncover Risk Factors and Target Therapy

Newswise — With potential changes to the definition of autism in the newest (fifth) edition of Diagnostic and Statistical Manual of Mental Disorders (DSM), due to be published in May, clinicians and researchers must recognize that children who fall under the diagnostic umbrella of autism spectrum disorder are as varied as those who carry the diagnosis of cancer, says autism expert Jennifer Pinto-Martin, MPH, MD, of the University of Pennsylvania School of Nursing. Some who work in the field have coined the word “autisms” to represent the many faces of the disorder.

The DSM, from the American Psychiatric Association, is the standard reference for the diagnosis of mental disorders and has an important influence on insurance coverage and access to educational support and therapeutic services, as well as research.

The new, more restrictive criteria would combine three subgroups on the autism spectrum into one category and require a child to display more pronounced symptoms to qualify for a diagnosis. The effect may be that it is harder for some more mildly affected children to qualify for insurance to cover therapeutic and educational support services.

Rather than debate about whether changes in diagnostic criteria are warranted or wise, the focus should be on the effects such a change would have, says Dr. Pinto-Martin, who directs the Center for Autism and Developmental Disabilities Research and Epidemiology (CADDRE) at Penn Nursing. CADDRE is one of six centers funded by the Centers for Disease Control (CDC) to study the prevalence and causes of autism spectrum disorders.

“The proposed changes raise important issues for both the parents of children on the autism spectrum and researchers focused on understanding the trends and risk factors for autism,” says Dr. Pinto-Martin. She is the lead researcher in the first large-scale study to find a link between low birthweight and children diagnosed with autism. Dr. Pinto-Martin’s work, supported by a $3 million grant from the National Institute of Mental Health, showed that premature infants are five times more likely to have autism than children born at a normal weight. The study appeared in the journal Pediatrics in October.

For families, the change provides an opportunity to seek educational support and therapeutic services that are tailored to the specific needs of their child rather than the one-size-fits-all approach so common today, says Dr. Pinto-Martin. By separating children into more homogeneous groups with respect to their needs and challenges, therapies can be designed to target the specific needs of each group.

“The challenges faced by children who function at the higher end of the spectrum would not diminish with a change in diagnostic criteria,” says Dr. Pinto-Martin. “Seeking ways to better address therapy and educational support needs of all children with autism must be a commitment and a goal in the face of changing eligibility.”

For autism researchers, she says, the proposed changes are both good and bad. The search for the cause of autism has been hampered by the heterogeneity of those who fall under the umbrella of the autism spectrum. Many researchers believe that the various sub-types of autism may have differing causes, just as there are different causes for the numerous types of cancer.

Refining the diagnostic criteria could help to sort those with the disorder into a more homogeneous group by requiring greater clarity and consistency in symptom presentation, says Dr. Pinto-Martin. This would enhance research efforts focused on uncovering risk factors for autism by refining the group under consideration. This is the strategy researchers follow for uncovering risk factors for cancer, sorting patients by the specific type of cancer and then looking for risk factors in that group. While there are some common risk factors across cancer types, there are also risk factors that are specific to each type. Researchers expect the same will be true for the sub-types of autism such as autistic disorder, pervasive developmental delay, and Asperger disorder.

Monitoring changes in the prevalence of autism over time, another important, ongoing research initiative, could be hampered by changes in the way children are labeled, Dr. Pinto-Martin explains. Tracking prevalence is one of the major tools in epidemiologic investigations because it gives important clues about etiology. Autism researchers may be faced with a decrease in prevalence due to a change in the way the diagnosis is defined. Sorting out any actual change in risk from an artificial increase or decrease due to a change in the size of the diagnostic umbrella will be made more difficult.

Says Dr. Pinto-Martin: “We must be cognizant of the potential effect of a decrease in reported prevalence using the new DSM criteria from research and clinical perspectives, and pay careful attention to the real and ongoing needs of children and families who are coping with autism, no matter the criteria used to make the diagnosis.”

Dr. Pinto-Martin is available for media inquiries about the proposed changes to the definition of autism in the DSM.

The University of Pennsylvania School of Nursing is one of the premier research institutions in nursing, producing new knowledge in geriatrics, pediatrics, oncology, quality-of-life choices, and other areas. Penn Nursing researchers consistently receive more research funding from the National Institutes of Health than any other private nursing school, and many master’s programs are ranked first in the country. This year, faculty, students, alumni, and staff celebrate 125 years of nursing at Penn.