The first prospective study of ethnic differences in the symptoms of autism in toddlers shows that children from a minority background have more delayed language, communication and gross motor skills than Caucasian children with the disorder. Researchers at the Kennedy Krieger Institute concluded that subtle developmental delays may be going unaddressed in minority toddlers until more severe symptoms develop.
While the prevalence of autism spectrum disorders (ASD) does not differ across racial and ethnic groups, some studies have shown that children of African American, Hispanic and Asian descent are less likely to receive an early diagnosis of autism than Caucasian children. In this new study, Dr. Rebecca Landa, director of the Center for Autism and Related Disorders at Kennedy Krieger Institute, investigated whether the symptoms of autism in toddlers play a role in this disparity in diagnosis as part of her work to improve access, education and outreach to minority communities.
"We found the toddlers in the minority group were significantly further behind than the non-minority group in development of language and motor skills and showed more severe autism symptoms in their communication abilities," says Landa, whose study included children and parents of African American, Asian and Hispanic descent. "It's really troubling when we look at these data alongside diagnosis statistics because they suggest that children in need of early detection and intervention are not getting it."
The study, published in the Journal of Autism and Developmental Disorders (Epub ahead of print), examined development in 84 toddlers with ASD at an average 26-28 months of age using three standardized instruments that evaluate child development. Children were evaluated by their caregivers using the Communication and Symbolic Behavior Scales Developmental Caregiver Questionnaire (CSBS-DP CQ) and by research clinicians using the Mullen Scales of Early Learning and the Autism Diagnostic Observation Schedule-Generic (ADOS). After controlling for participants' socioeconomic status, all three tools indicated a significant difference between minority and non-minority children.
Previous studies published by Dr. Landa and her colleagues at Kennedy Krieger show that detection of ASD is possible at as early as 14 months of age. While early diagnosis is crucial for accessing intervention services, studies examining children from minority groups suggest considerable delays in the diagnosis of ASD in these children relative to their Caucasian peers.
Dr. Landa points to cultural differences in what communities perceive as typical and atypical development in young children, the relationships between families and respected community physicians, and the stigma that some cultures place on disability as areas where education and awareness could have meaningful impact.
"Addressing cultural influences gives us a clear target to improve service delivery to minority children, but these findings may also suggest biological and other culturally-related differences between Caucasian and minority children with autism," says Landa. "There are other complex diseases that present differently in different ethnic groups and more research is needed to investigate this possibility."
The findings of this research prompted Dr. Landa and her team to begin a study that will document the age at which minority parents first noticed signs of developmental disruption in their children, the specific nature of the behavior that concerned them, and the children's intervention history. Additional research is also needed to study group-specific differences in the presentation of autism symptoms between a variety of minority groups.
"Although questions remain on why these differences exist, by taking steps to develop more culturally-sensitive screening and assessment practices, with a special focus on educating parents, clinicians and health educators, I believe we can empower parents to identify early warning signs and ensure minority children have the same access to services as their Caucasian peers," says Landa.
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To read an online discussion with Dr. Landa about this work, visit http://www.kennedykrieger.org/landa-discussion-022112.