Addict with rest disturbed becomes confused (10)
I believe the answer is:
distracted
'confused' is the definition.
(distracting is a kind of confusing)
'addict with rest disturbed' is the wordplay.
'with' is a charade indicator (letters next to each other).
'disturbed' is an anagram indicator.
'addict' after 'rest' is 'restaddict'.
'restaddict' anagrammed gives 'DISTRACTED'.
'becomes' is the link.
(Other definitions for distracted that I've seen before include "Preoccupied" , "Diverted (attention) from (something)" , "Troubled - ID card test (anag)" .)