PREMORBID PREVALENCE OF ADHD AND DEVELOPMENT OF SECONDARY ADHD AFTER CLOSED-HEAD INJURY

Objective: To determine premorbid prevalence of attention-deficit hype ractivity disorder (ADHD) in children with moderate and severe closed head injury (CHI), to determine incidence of ADHD 1 year after injury, and to characterize children who develop ADHD by demographic, neurops ychiatric, and outcome variables. Method: Ninety-nine children who had severe and moderate CHI were followed up for 1 year. Premorbid and 1- year postinjury psychiatric status were ascertained by parent and chil d structured interviews and questionnaires measuring affective labilit y, aggression, apathy, and social judgment. Results: Premorbid prevale nce of ADHD was 0.20, significantly higher than in a reference populat ion (0.045). Fifteen of the remaining 80 children (0.19) developed ful l ADHD criteria (except for age of onset) by the end of the first year . Children who developed secondary ADHD (S-ADHD) had significantly gre ater premorbid psychosocial adversity, posttraumatic affective labilit y and aggression, posttraumatic psychiatric comorbidity, and overall d isability than children who did not develop S-ADHD. Conclusions: There is an excess prevalence of premorbid ADHD among children who present with moderate and severe CHI. Children with high psychosocial adversit y are more likely to develop S-ADHD after CHI. S-ADHD has criteria in common with personality change due to CHI, a deficit in behavioral inh ibition being the major overlapping feature.