A new study by the UC Davis MIND Institute finds a connection between gestational age and attention deficit/hyperactivity disorder (ADHD) symptoms in children with Down syndrome. The research was published in Scientific ReportsThe study focused on children who were born at 35 weeks gestation (or older). It found that ADHD symptoms were more common in children born earlier in their gestational years. Gestational age refers to the time a fetus has been developing since the beginning of a pregnancy or gestation.
“Despite growing evidence suggesting that ADHD symptoms in later years can be predicted by gestational ages, this has not been studied in Down syndrome children,” said Laura del Hoyo Soriano a neuropsychologist and postdoctoral researcher in the Department of Psychiatry and Behavioral Sciences and the study’s lead author. This makes the study meaningful and a significant first step in understanding factors that contribute to ADHD symptoms in this group.
The study involved 49 boys and 56 women (6-18 years) who were born at least 35 weeks gestation after Down syndrome. The Down Syndrome Cognition Project involved the children.
The study was based on the children’s medical records as well as questionnaires completed by their mothers. These questionnaires included well-established measures of intelligence and ADHD symptoms. The researchers found that ADHD symptoms were more common in children who were born earlier than normal, even after accounting for cognitive abilities and age.
Differentiating ADHD symptoms from Down syndrome intellectual disability
ADHD is frequently associated with Down syndrome. It is characterized by inattention and distractibility, poor impulse control, trouble focusing, and inattention. It can be difficult to distinguish ADHD symptoms from those caused by Down syndrome.
“It can be difficult to distinguish between a comorbid diagnosis, and a Down syndrome phenotype. Del Hoyo Soriano noted that ADHD symptoms in intellectually disabled people should be studied.
She also points out that there was no correlation between ADHD symptoms and general cognition in the study. This reinforces the separate diagnosis of ADHD.
Leonard Abbeduto, co-author of this study and director at the UC Davis MIND Institute, said, “It’s interesting that gestational ages are also related to ADHD symptoms” “Our findings support the notion that ADHD is not an inherent trait of Down syndrome. They are more likely the result if additional factors are involved.”
Researchers considered many factors in their analysis, such as participants’ age, sex and cognitive level, family income, education and birth date. To verify the validity of their findings, they also performed several analyses. They also removed children who were on medication for ADHD.
ADHD and age
The study shows that ADHD can present differently as people age. ADHD symptoms were more common in younger children with Down syndrome than in older ones. This is consistent with research that was done in the general population.
Del Hoyo Soriano stated that “more attention must be paid to the care of pre-term infants, even those between 35-39 weeks, and possibly even more for those with Down syndrome.” “The potential consequences of early interventions could be substantial.”
Materials provided by University of California, Davis Health. Note: Content can be edited for style or length.