The young appear to be depressed (5)
I believe the answer is:
brood
This could be a double definition.
'the young' is the first definition.
(thesaurus)
'to be depressed' is the second definition.
(I've seen this in another clue)
'appear' acts as a link.
I am not very happy about this link. It may belong to one of the definitions.
Can you help me to learn more?
(Other definitions for brood that I've seen before include "Offspring" , "Meditate moodily" , "Sulk; incubate" , "Meditate, fret" , "Ponder mournfully" .)