Relating to the mind (7)
'relating to the mind' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for mental that I've seen before include "off trolley" , "Light allowing vehicles to turn while ahead is red" , "Pertaining to the mind" , "Cerebral" , "Nuts" .)
(Other definitions for psychic that I've seen before include "One is apparently sensitive to things beyond the rest of us" , "One is apparently sensitive to the paranormal" , "Spiritual" , "Chic spy (anag.)" , "Spiritualistic medium" .)