Shy chap high with pot could be an anti-social person (10)
I believe the answer is:
psychopath
'an anti-social person' is the definition.
(a psychopath doesn't care about other people)
'shy chap high with pot' is the wordplay.
'high with' indicates anagramming the letters (can mean drunk or on drugs and hence disordered).
'shy'+'chap'='shychap'
'shychap' mixed up with 'pot' makes 'PSYCHOPATH'.
'could be' acts as a link.
(Other definitions for psychopath that I've seen before include "One emotionally unstable, often violent" , "disturbed individual" , "nut" , "One with abnormal or violent social behaviour" , "One who commits violent acts without guilt" .)