Symptoms of attention-deficit/hyperactivity disorder following traumatic brain injury in children

We investigated changes in inattentive and hyperactive symptoms over 2 years following traumatic brain injury (TBI) in relation to preinjury attention-deficit/hyperactivity disorder (ADHD), injury, and socioeconomic status (SES) variables. Postinjury stimulant medication treatment was also documented. Of 175 consecutive patients of ages 5 to 15 years with acute TBI, 148 consented, including 114 without preinjury ADHD (mean age, 10.0 years, SD = 2.76) and 34 with preinjury ADHD (mean age 10.36 years, SD = 2.75). The Schedule for Affective Disorders and Schizophrenia for School-Age Children, Present and Lifetime Version, was administered at baseline and at 6, 12, and 24 months post-injury to assess the presence of nine core inattentive and nine hyperactive symptoms and associated impairment. The baseline assessment was performed within 1 month post-injury to establish preinjury diagnosis.

Nonlinear change in inattentive symptoms in patients without preinjury ADHD contrasted with higher and more stable symptom levels in children with preinjury diagnosis, including the cubic trend (chi2(1) = 6.23, p = .0126). There was also a significant interaction of group x gender effect (chi2(1) = 4.08, p = .0435) as males had higher numbers of inattentive symptoms than females in the preinjury ADHD group. Change in hyperactive symptoms over time also differed by group, including both linear (chi2(1) = 5.42, p = .0199) and cubic trends (chi2(1) = 8.91, p = .0029), reflecting greater and more frequent fluctuations in children without preinjury ADHD. Socioeconomic level also contributed to change in hyperactive symptoms as reflected by the interaction of SES and linear time (chi2(1) = 6.91, p = .009), as well as quadratic time (chi2(1) = 4.90, p = .027). Occurrence of ADHD diagnosed post-injury ranged from 14.5% (12 months) to 18.3% (24 months) in the group without preinjury ADHD compared with a range from 86.4% (12 months) to 96.2% (6 months) in children with preinjury ADHD. In children without preinjury ADHD, SES was the only patient variable that predicted onset of ADHD, t(110) = -2.85, p = .0052. Treatment with stimulant medication post-injury was more frequently associated with preinjury ADHD (39% vs 7% of children without preinjury ADHD), p< .0001 (Fisher exact test). Children with preinjury ADHD who were treated pre-injury with stimulant medication had fewer total symptoms at 24 months post-injury relative to untreated patients with preinjury ADHD (F[1,14] = 3.93, p = 0.069, Cohen's d = 1.28).

Change in ADHD symptoms after TBI varies with preinjury diagnosis, reflects injury severity in children without preinjury ADHD, and is treated with stimulant medication mainly in those patients with preinjury ADHD.