Awful moan that is indicating isolation and anxiety (6)
I believe the answer is:
anomie
'isolation and anxiety' is the definition.
(anomie means social isolation or disorder)
'awful moan that is' is the wordplay.
'awful' indicates an anagram.
'that is' becomes 'ie' (short for Latin 'id est', 'that is').
'moan' is an anagram of 'anom'.
'anom'+'ie'='ANOMIE'
'indicating' acts as a link.
(Other definitions for anomie that I've seen before include "lack of ethical values" , "State of isolation within society" , "loss of purpose" , "Hopelessness" .)