When facing problem, journalist may be taken in (7)
I believe the answer is:
assumed
'taken in' is the definition.
(assuming is a kind of taking in)
'when facing problem journalist' is the wordplay.
'when' becomes 'as'.
'facing' is a charade indicator (letters next to each other).
'problem' becomes 'sum' (arithmetic problem).
'journalist' becomes 'ed' (short for editor).
'as'+'sum'+'ed'='ASSUMED'
'may be' acts as a link.
(Other definitions for assumed that I've seen before include "Bogus" , "Accepted as true without actual proof" , "Taken for granted - feigned" , "Fancied" , "Took upon oneself" .)