A new study suggests a trend toward developing hyperactivity among typically developing elementary school-aged siblings of preschoolers diagnosed with autism.
The study also supports the idea that mothers of young children with autism experience more depression and stress than mothers with typically developing children. The study appears in the March issue of Focus on Autism and Other Developmental Disabilities.
While the impact on older siblings was not statistically significant, the trend may indicate the presence of symptoms associated with broader observable autism characteristics seen in previous studies, says Laura Lee McIntyre, director of the University of Oregon's school psychology program.
Previous research projects have netted mixed findings, but much research has suggested that families dealing with autism--especially brothers and sisters of a child with autism--also experience symptoms similar to autism: widespread abnormalities of social interactions, communication and behavior.
The new study gives a fresh look at autism's early effects on families by comparing control and experimental groups whose ages, education and socioeconomic situations were virtually identical. Twenty families had a preschooler (ages 2 to 5) diagnosed with autism and a typically developing older elementary school sibling (ages 6 to 10); the control group of 23 families did not have an child with autism. Older children with diagnosed learning or mental disabilities were excluded.
"We know there are risk factors, but we don't know if they result from having a child with autism or if there are genetic predispositions as part of the broader autism picture," McIntyre said. "Are these difficulties the result of child-rearing challenges, or are they negatively impacted because of shared genetic risks? Our sample was very clean, and that's good for science but not necessarily as good for generalizing our findings, but I'm confident with the results we found in this particular sample."
McIntyre and her doctoral student Nicole Quintero studied families chosen in New York. They looked closely at sibling adjustments, involving social, behavioral and academic performance as recorded by both parents and teachers, and at the well-being of the mothers, whose average age was 36 and 94 to 95 percent of whom were married. The median age of older siblings was 7 and most were first- or second-grade students.
"Contrary to what has been found by many researchers, we found that older siblings were pretty well adjusted, with no significant differences in parent-reported or teacher-reported social skills," said McIntyre. "These are all typically developing kids."
Teachers, however, reported slightly more behavioral problems for the siblings of children with autism than control siblings. "There was a trend toward significance," she said.
The problems resembled hyperactivity but not at levels generally attributed to attention deficit hyperactive disorder (ADHD). Teacher reports noted these children exhibited slightly more fidgeting, movement and attention problems.
"Children with siblings with autism may be experiencing some subclinical symptoms of hyperactivity or attention problems," noted McIntyre. "Parents didn't report seeing such things at home. Teachers see these children in a more structured environment. Siblings of children with autism may be at heightened risk for developing problems, potentially over time."
Siblings of children with autism probably should be watched with appropriate academic supports in place, she said. "Our findings are rather positive overall, but these kids should be on our radar screens. These kids may start school OK, at least those from healthy families, but they may demonstrate difficulties over time. However, it has been shown that around 30 percent of siblings of autistic children have some associated difficulties in behavior, learning or development."
The finding that moms with children with autism were more stressed and depressed compared to moms of typically developing preschool children "was not surprising at all," McIntyre said. "That finding is robust in existing literature, so even though this sample involves highly organized, motivated and willing mothers, in comparison to other moms with two or more children, they are reporting more stress and more depression."
Mothers of children with autism, she added, need assistance for day-to-day child-rearing activities to give them some time to be individuals. As part of her research and clinical work at the University of Oregon's nationally recognized Child and Family Center, she is looking at interventions that support parents and help kids with their daily living skills and behavior management.
The research was partially funded by the National Institute of Child Health and Human Development.