The word psyche
comes from the greek 'soul
' and as such can mean the whole of the essence
of a human being as it refers to their emotions
and thought processes
, and their actions
, and influence on others. It might also refer to a metaphysical reality
that give a person an identity
, but that is another issue.
One is hard pressed to prove damage to an entity that cannot be materially examined. Nevertheless, a damaged psyche shows itself up in a number of ways, including repetitive thoughts, consistently irrational behaviour, out of context behaviour, self damaging behaviour, wild mood swings, or complete lack of emotion, as well as other signs.
These things are difficult to quantify scientifically, and it can be argued that almost everyone suffers all of these at one time or other, so we may not as a society have an objective platform upon which to deem a person psychologically damaged. That doesn't stop us locking them up, or trying to help them though. But again, that's another node.