Depression of jet-setter? (5,3)
I believe the answer is:
black dog
'depression' is the definition.
(I've seen this before)
'jet-setter?' is the wordplay.
'jet' becomes 'black' ('black' can be similar in meaning to 'jet').
'setter?' becomes 'dog' (a setter is a type of dog).
'black'+'dog'='BLACK DOG'
'of' acts as a link.
(Other definitions for black dog that I've seen before include "Melancholy, depression" , "Animal representing depression" , "Depression - could be a Labrador?" .)