What is the cause of disturbed mind?
Bhagavad Gita(BG) Lord Krishna says to Arjuna BG 2.60 : The senses are so strong and impetuous, O Arjuna, that they forcibly carry away the mind even of a man of discrimination who is endeavoring to control them. BG 2.62 : While contemplating the objects of the senses, a person develops attachment for them, and from such attachment lust develops, and from lust anger arises. BG 2.63 : From anger, complete delusion arises, and from delusion bewilderment of memory. When memory is bewildered, intelligence is lost, and when intelligence is lost one falls down again into the material pool. BG 2.67 : As a strong wind sweeps away a boat on the water, even one of the roaming senses on which the mind focuses can carry away a man's intelligence and can disturb the mind.