It is also narrated in Bihār al-Anwār that one day the messenger of Allah (S) was passing by a group of people intent on watching something. When he (S) enquired about this they said that they were watching a mad man perform funny antics. The Prophet (S) said that the man is not mad, rather he was suffering from a nervous disorder.
Then the Holy Prophet (S) asked the people if they would like to know who is a mad man. His companions expressed their willingness. The Prophet (S) said:
“The insane is the one who walks in a proud manner and looks right and left in exultation; moving his shoulders and sides in a vain fashion; and at the same time he expects the Almighty to grant him Paradise. Whereas he is busy in disobeying Allah and people are not safe from his mischief and neither do they expect any goodness from him. This is the (real) mad man.”( Bihar Al Anwar vol 73)