Troubled horse starts to get every disorder (6)
I believe the answer is:
nagged
'troubled' is the definition.
The definition and answer can be both to do with human feelings as well as being past participle verbs.
Perhaps you can see an association between them that I can't see?
'horse starts to get every disorder' is the wordplay.
'horse' becomes 'nag' (term for an old horse).
'starts to' says to take the initial letters.
The first letters of 'get every disorder' is 'ged'.
'nag'+'ged'='NAGGED'
Can you help me to learn more?
(Other definitions for nagged that I've seen before include "Constantly complained like wife to husband" , "Persistently harassed" , "Annoyed persistently" , "Badgered or scolded persistently" , "Went on" .)