What troubles me is adult being affected (9)
I believe the answer is:
simulated
'being affected' is the definition.
(thesaurus)
'what troubles me is adult' is the wordplay.
'what troubles' indicates anagramming the letters (letters get troubled or disturbed).
'me'+'is'+'adult'='meisadult'
'meisadult' is an anagram of 'SIMULATED'.
(Other definitions for simulated that I've seen before include "Feigned, imitated" , "Pretended" .)