Anxiety caused by arrest (12)
I believe the answer is:
apprehension
This clue is a double definition.
'anxiety' is the first definition.
(anxiety can mean a feeling of apprehension)
'arrest' is the second definition.
(synonyms)
'caused by' is the link.
(Other definitions for apprehension that I've seen before include "Trepidation" , "Anxious anticipation; understanding" , "Fearful anticipation" , "The catching" , "butterflies" .)