Title-holder's depressing experience, losing head (5)
I believe the answer is:
owner
'title-holder's' is the definition.
(I've seen this before)
'depressing experience losing head' is the wordplay.
'depressing experience' becomes 'downer' (I've seen this before).
'losing head' means to remove the first letter.
'downer' with its initial letter taken off is 'OWNER'.
(Other definitions for owner that I've seen before include "Person having property" , "One who has something" , "The one in lawful possession" , "Title holder?" , "Person with legal title to something" .)