Pause to get depressed and collapse (9)
I believe the answer is:
breakdown
'collapse' is the definition.
(breakdown is a kind of collapse)
'pause to get depressed' is the wordplay.
'pause' becomes 'break' (break is a kind of pause).
'to get' means one lot of letters go next to another.
'depressed' becomes 'down' ('down' can be a synonym of 'depressed').
'break'+'down'='BREAKDOWN'
'and' acts as a link.
(Other definitions for breakdown that I've seen before include "Collapse - analysis" , "Mechanical failure" , "Detailed analysis" , "Nervous disorder" , "Analysis < of separation" .)