Improve state of disturbed heartless children (6)
I believe the answer is:
enrich
'improve state of' is the definition.
(to enrich is to enhance or improve)
'disturbed heartless children' is the wordplay.
'disturbed' is an anagram indicator (the order of letters is disturbed).
'heartless' says to hollow out the word (remove centre letters).
'children' with its centre removed is 'chiren'.
'chiren' with letters rearranged gives 'ENRICH'.
(Other definitions for enrich that I've seen before include "Give money" , "Make fuller flavoured" , "Grace" , "Heighten" , "Decorate" .)