http://www.theatlantic.com/health/archive/2014/07/how-childhood-trauma-could-be-mistaken-for-adhd/373328/

This article states that ADHD may be wrongly diagnosed instead of watching for symptoms of trauma- ie dissociation, inattenitivity, hypervigilance. Impulsivity, another symptom of ADHD may be brought on an overactive stress response.