The link between Attention-Deficit/Hyperactivity Disorder (ADHD) and academic performance involves a complex interaction of genes and environment, a new study has found.
The study found genetic influence to be greater on reading than for math, while shared environment (e.g., the home and/or school environment) influenced math more so than reading.
Lee A. Thompson, chair of Case Western Reserve University's Psychological Sciences Department, and colleagues studied twins to look simultaneously at the genetic and environmental influences on reading ability, mathematics ability, and the continuum of ADHD behavior.
They analyzed 271 pairs of ten-year-old identical and fraternal twins and collected data yearly about their math and reading ability.
Their study focused on two ADHD symptoms: inattention and hyperactivity, which are viewed as extremes of their respective attention and activity continuums.
The researchers assessed reading ability by evaluating the twins' recognition and pronunciation of words and passage comprehension.
They measured the twins' capacity for mathematics by focusing on the twin's ability to solve problems, understanding of concepts, computational skills, and the number of computations completed in 3 minutes.
They then determined the similarities in genetic and environmental influence between ADHD symptoms and reading and between the symptoms and mathematics.
The researchers found that there are some general genes that influence the symptoms of ADHD simultaneously with reading and mathematics ability and some genes that influence each specifically.
This study also found that both inattention and hyperactivity were related to academics.
The study was published in Psychological Science, Vol. 21.