This study followed 579 children who met criteria for the combined type of ADHD when they were between 7 and 9.9 years old (grades 1 through 4). Most were boys (80%) and most were Caucasian (62%). They took part in a large multisite study known as the MTA. Researchers looked at their academic outcomes years later, at average ages of 14.9 and 16.8. The main analyses used 436 of these children.
The researchers found that standardized achievement test scores and school grades were only moderately related to each other. Each also had its own separate set of predictors.
Childhood inattention had only a small direct link to later achievement (range −.02 to .12). Its effect worked mostly in an indirect way. Inattention appeared to shape academic outcomes through how teachers rated a child's classroom performance and through how parents rated the child's ability to manage homework materials.
Medication use and receiving special education did not predict grades.
The authors noted limits. About three fourths of the children received 14 months of intensive treatment in childhood, and all had the combined type of ADHD. Medication use, special education, and grades came from parent report.
Source: Langberg J, Molina B, Arnold L, et al.. Patterns and Predictors of Adolescent Academic Achievement and Performance in a Sample of Children with Attention-Deficit/Hyperactivity Disorder. Journal of Clinical Child & Adolescent Psychology (2011). doi:10.1080/15374416.2011.581620