menticide

[fr. L. ment-, mens; mind + cidium, killing]
the undermining or destruction of a person's mind or will, esp. by systematic means such as mental and physical torture, extensive interrogation, suggestion, training, and narcotics: brainwashing

IN BRIEF: n.- A systematic and intentional undermining of a person's conscious mind for the purpose of instilling doubt and replacing that doubt with ideas and attitudes directly opposite to his normal ideas and attitudes