Abstract
Objective. Consequences of mild head injury for behavioral adjustment have not been well researched, and little is known about the long-term effects of mild head injury for attention-deficit hyperactivity disorder (ADHD). Methods. In this longitudinal study of 418 children in Jintan City, China, parents reported children's history of head injury at age 6 years, and the Child Behavior Checklist was used to measure child iDSM-IV-oriented ADHD at ages 6 (Wave I) and 12 years (Wave II). Regression models were used to calculate the long-term (Wave II) effect of mild head injury on diagnosed ADHD, while controlling for diagnosed ADHD in Wave I. Results. Fifty-seven children (13.6%) had a single injury and 42 (10.0%) had multiple injuries before the age of 6 years. The long-term effect of multiple mild injury on ADHD at age 12 years was significant (R(2) = 0.103, P < .05), even after controlling for ADHD at age 6 years. Conclusions. Multiple, but not single, mild head injuries before the age of 6 years had a significant long-term effect on ADHD. Thus, injuries traditionally overlooked and underreported still pose significant risks to children's long-term behavioral development.