Every now and then, carnage on street leads to anxiety (5)
I believe the answer is:
angst
'to anxiety' is the definition.
(angst is a type of anxiety)
'every now and then carnage on street' is the wordplay.
'every now and then' means one should take alternating letters (letters selected at regular intervals).
'on' is a charade indicator (letters next to each other).
'street' becomes 'st' (abbreviation).
The alternate letters of 'carnage' are 'ang'.
'ang'+'st'='ANGST'
'leads' is the link.
(Other definitions for angst that I've seen before include "Profound feeling of anxiety or dread" , "Acute but unspecified feeling of worry" , "feeling worried?" , "Oppressive feeling of worry, guilt" , "Terrible butterflies" .)