Doctor reunited with slimmer — problem due to withdrawal (8,7)
I believe the answer is:
delirium tremens
'problem due to withdrawal' is the definition.
(condition caused by alcohol withdrawal)
'doctor reunited with slimmer' is the wordplay.
'doctor' indicates an anagram.
'with' is a charade indicator (letters next to each other).
'reunited' put after 'slimmer' is 'slimmerreunited'.
'slimmerreunited' anagrammed gives 'DELIRIUM TREMENS'.
(Other definitions for delirium tremens that I've seen before include "Condition seen in alcoholics" , "Shakes" , "the bottle for this?" .)