Capital boom possibly follows depression (7)
I believe the answer is:
colombo
'capital' is the definition.
(Colombo is an example)
'boom possibly follows depression' is the wordplay.
'possibly' indicates an anagram.
'follows' means one lot of letters go next to another.
'depression' becomes 'col' (geographical term for a low point).
'boom' is an anagram of 'ombo'.
'ombo' put after 'col' is 'COLOMBO'.
(Other definitions for colombo that I've seen before include "Main port of Sri Lanka" , "Sri Lankan city" , "Sri Lankan capital" , "Asian capital" , "City of Sri Lanka" .)