Anxiety produced by arrest (12)
I believe the answer is:
apprehension
This clue is a double definition.
'anxiety' is the first definition.
(I've seen this before)
'arrest' is the second definition.
('apprehension' can be a synonym of 'arrest')
'produced by' is the link.
(Other definitions for apprehension that I've seen before include "Fear" , "Fearful anticipation" , "Understanding; anxiety" , "Trepidation" , "butterflies" .)