BOSTON (WBZ NewsRadio) — A new study by researchers at Brown University's Department of Psychiatry and Human Behavior has found that females with Autism are diagnosed an average of 1.5 years later than males, and that people with Autism often have co-occurring medical and psychiatric conditions.
Study author Stephen Sheinkopf told WBZ NewsRadio's Laurie Kirby that his research team analyzed the first 1,000 patients at the Rhode Island Consortium for Autism Research and Treatment. The aim of the study was to identify the key trends in the presentation and diagnosis of Autism Spectrum Disorder (ASD.)
"We enrolled over 20 percent of the children with Autism in the state of Rhode Island, and adults as well. One of the findings was that females with Autism tend to be diagnosed over a year and a half later than boys," Sheinkopf said.
Autism is a developmental disorder usually marked by two specific kinds of behaviors; restricted or repetitive behaviors, and delays in social skills and communication. According to Sheinkopf, Autism is a varied condition that can present very differently in individuals across the spectrum.
"There are some children who have life long significant impairments who will never speak. There are other children with Autism who go onto high levels of achievement, who graduate college and have successful careers... so it's quite a varied condition."
Sheinkopf said the model for diagnosing Autism seems to be centered on typically male signals of the disorder. Since females tend to express traits of ASD in different ways, their signs can often be misdiagnosed or missed altogether.
"Girls may have less severe language delays early on, and that may make it more difficult for parents and pediatricians to identify them as having a need for an evaluation," Sheinkopf said. According to a 2005 study from Stanford, females also tend to display less obvious repetitive behaviors, possibly because they are more likely to want to control such movements in public.
The Brown University study found that in Rhode Island, more than four times as many boys as girls were diagnosed with Autism. That number also reflects the diagnosis ratio between the genders on the national level, according to the Center for Disease Control and Prevention.
Sheinkopf told WBZ NewsRadio's Laurie Kirby that the discrepancy is not necessarily an issue of gender bias. "It's unclear whether it's bias, or whether its a different type of presentation or expression of the disorder. That means we need to make improvements in how we design tests to screen for and diagnose Autism, to make sure we are most accurate in both girls and boys," he said.
According to Brown University, most of the study's participants had received an Autism diagnosis prior to the study, whereas some individuals were referred to the study without any evidence or diagnosis of the disorder.
Sheinkopf explained why those undiagnosed participants were important to the research. "The group that was diagnostically less clear-cut represents the complexity that clinicians encounter on a daily basis, so it's a realistic sample in that sense. This full range of heterogeneous Autism presentation is rather unique to our study."
Another major finding of the Brown University study was that there is a high prevalence of co-occurring psychiatric and medical conditions for people with Autism. According to Sheinkopf, those other diagnoses can often cloud the signs of Autism, especially in girls.
"There is a large clinical burden, additional disabilities and psychiatric diagnoses, across the lifespan for people with Autism. Researchers and clinicians need to be particularly aware and sensitive to issues of depression, anxiety, and other mental health conditions that can co-occur with autism, and need to be the focus of care often times."
Sheinkopf said that on a national level, the average age for ASD diagnosis is around four years old. But, he explained, that depends on the level of language and cognitive delay. "Children with more severe language and cognitive delays tend to be referred to clinics earlier on. One thing we're trying to improve is how to identify autism in children who have less severe language delays, but still significant needs in other areas."
The Brown University Autism study also found that nearly half of the participants reported having another neurodevelopmental disorder alongside Autism, most commonly ADD, ADHD, intellectual disability, a psychiatric disorder, or a neurological condition like epilepsy or tics.
Co-author of the study, Dr. Eric Morrow said he believes longitudinal studies are important in understanding how to better diagnose and care for people on the Autistic spectrum. "I think we're going to learn even more when we follow children from a very young age as they develop, including into adulthood," Morrow said.
WBZ NewsRadio's Laurie Kirby (@LaurieWBZ) reports:
The Brown University team's study is now published in the journal Autism Research, the official journal for the international society of research into ASD.