Girls with mild autism typically diagnosed later than boys
Girls who are on the milder end of the autism spectrum tend to be diagnosed later than boys, a new study has found. The difference in age at the time of diagnosis may be attributed to the fact that girls with mild autism exhibit less severe symptoms.
The study found that doctors diagnosed girls with Asperger's syndrome -- an autism spectrum disorder (ASD) characterized by social impairment, communication difficulties, and restrictive, repetitive, and stereotyped patterns of behavior -- and pervasive developmental disorder months later than boys who had the same disorders. Study co-author Dr. Paul Lipkin, director of the Interactive Autism Network at Kennedy Krieger Institute in Baltimore said the difference in age at the time of diagnosis could be because mild autism in girls exhibits itself as social awkwardness, while boys with mild autism tend to display physical symptoms that are more apparent.
"The girls' problems seemed greatest in terms of social interpretation, which is obviously much more subtle and less apparent," Lipkin said. "Boys were worse than the girls in areas that involve repetitive behaviors or unusual mannerisms. The problems the boys were having were overt and more readily recognized."
Dr. Lipkin and his colleagues analyzed data on people with ASD and their family members using the Krieger Institute’s online registry of 50,000 people. Nearly 10,000 registrants reported how old they were when they were first diagnosed with ASD, and about 5,000 had undergone a test called the Social Responsiveness Scale to identify the severity of their social impairment.
While girls and boys "classic" severe autism received a diagnosis at about the same time, girls with pervasive developmental disorder -- which impacts the development of many basic skills -- generally received a diagnosis at an average age of 4 years, compared to 3.8 years for boys with the same condition. Girls with Asperger's were also diagnosed at an average of 7.6 years, compared to 7.1 years for boys.
Lipkin said the symptoms also differed between boys and girls. Girls struggled with the ability to interact with others and recognize social cues, and had trouble interpreting requests and understanding jokes. They were also unable to read into people's tone of voice and facial expressions and took things too literally. Boys engaged in repetitive behaviors and unusual mannerisms such as flapping their hands.
The research is set to be presented Tuesday at the Pediatric Academic Societies annual meeting in San Diego, but the findings are considered preliminary until they are published in a peer-reviewed journal.
A recent study found that parents often notice signs of autism in their young children before a doctor makes an official diagnosis.
Lori Sacrey, a postdoctoral fellow in the Department of Pediatrics at the University of Alberta said that the earlier doctors can start with a child with ASD, the better the prognosis will be.
“If you can identify a child at a heightened risk earlier, before their first birthday, then you can start working with them to address early developmental difficulties, which can ultimately enhance their skill development and improve their outcomes,” she said.
"Parents play a critical role in implementing these interventions, building learning opportunities into everyday caregiving and play activities.”
According to the CDC, about 1 in 68 children in the United States has been identified with ASD. The disorder is almost five times more common in boys (1 in 42) than it is in girls (1 in 189).