_:vb50947362 . _:vb50947362 . _:vb50947362 "url:http://en.wikipedia.org/wiki/Attention-Deficit_Hyperactivity_Disorder"^^ . _:vb50947362 . _:vb50947362 "A specific developmental disorder that is characterized by co-existence of attentional problems and hyperactivity, with each behavior occurring infrequently alone and symptoms starting before seven years of age."^^ . _:vb50947362 . _:vb50947362 .