Traumatic Brain Injury Associated With Higher Risk for Secondary ADHD
The type and severity of injury were associated with increased risk for secondary ADHD.
Early childhood traumatic brain injury (TBI) was associated with increased risk for secondary attention-deficit/hyperactivity disorder (SADHD), according to new results published in JAMA Pediatrics.
Researchers conducted a concurrent cohort study of children age 3 to 7 years hospitalized overnight for TBI (n=81) or orthopedic injury (control group; n=106). Parents completed assessments at baseline and at several additional intervals until a mean value of 7 years post-injury. In addition to evaluating the relationship between TBI and SADHD risk, investigators also assessed potential environmental predictors of SADHD, including family functioning and maternal educational level.
Of 187 children included across both study groups, 48 (25.7%) met the diagnostic criteria for SADHD. Severe TBI (hazard ratio [HR] 3.62; 95% CI, 1.59-8.26) was associated with increased risk for SADHD developing compared with the orthopedic injury group. The main-effects model developed by researchers showed that the complicated mild TBI and moderate TBI groups did not differ significantly in SADHD risk from the orthopedic injury group.
Results from the interaction-effects model demonstrated that greater family dysfunction was associated with an increased risk for SADHD in the TBI group (HR 4.24; 95% CI, 1.91-9.43) and had a minimal effect on the risk for ADHD in the orthopedic injury group (HR 1.32; 95% CI, 0.36-4.91). Lower maternal educational level was also a predictor for SADHD for each study group (HR 0.34; 95% CI, 0.18-0.66).
Across the spectrum of TBI severity, the risk for SADHD was increased and most strongly associated with severe TBI. SADHD developed within the first 18 months of injury in most children with severe TBI, and researchers emphasized the importance of continued monitoring post-TBI. Additionally, the association between family dysfunction and risk for SADHD may indicate a particular need for survey of family functioning. Researchers noted that patient-reported data are susceptible to reporting bias, and that their SADHD cutoff may have excluded patients displaying ADHD-adjacent behavior, thus limiting data generalizability. For future studies, scientists suggested the inclusion of a wider range of injury severity and a more in-depth assessment of environmental and genetic factors to better understand post-injury risk for SADHD developing in adolescents and children.
Narad M, Kennelly M, Zhang N, et al. Secondary attention-deficit/hyperactivity disorder in children and adolescents 5 to 10 years after traumatic brain injury [published online March 19, 2018]. JAMA Pediatrics. doi:10.1001/jamapediatrics.2017.5746