Confused and bothered having mounted debts (9)
I believe the answer is:
delirious
'confused' is the definition.
(thesaurus)
'bothered having mounted debts' is the wordplay.
'bothered' becomes 'riled' ('rile' can be a synonym of 'bother').
'having mounted' shows that the letters should be reversed in order (in a down clue, letters mount up).
'debts' becomes 'IOUs' (promises to pay debts).
'riled' back-to-front is 'delir'.
'delir'+'ious'='DELIRIOUS'
'and' is the link.
(Other definitions for delirious that I've seen before include "Ecstatic" , "Highly excited - hallucinating" , "In a state of wild excitement" , "In wild ecstasy" , "Frenzied" .)