The disorder hardly seemed to exist before the stimulant Ritalin came along.
( ( The disorder ) ( hardly ( ( seemed ( to ( exist ( before ( ( the ( stimulant Ritalin ) ) ( came along ) ) ) ) ) ) . ) ) )
(ROOT (S (NP (DT The) (NN disorder)) (ADVP (RB hardly)) (VP (VBD seemed) (S (VP (TO to) (VP (VB exist) (SBAR (IN before) (S (NP (DT the) (NN stimulant) (NN Ritalin)) (VP (VBD came) (PRT (RP along))))))))) (. .)))
The disorder didn't seem to be as common when Ritalin wasn't around. 
( ( The disorder ) ( ( ( did n't ) ( seem ( to ( ( be ( as common ) ) ( when ( Ritalin ( ( was n't ) around ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT The) (NN disorder)) (VP (VBD did) (RB n't) (VP (VB seem) (S (VP (TO to) (VP (VB be) (ADJP (RB as) (JJ common)) (SBAR (WHADVP (WRB when)) (S (NP (NNP Ritalin)) (VP (VBD was) (RB n't) (ADVP (RB around)))))))))) (. .)))