derange

from The American Heritage® Dictionary of the English Language, 5th Edition.

• transitive verb To disturb the order, arrangement, or functioning of.
• transitive verb To upset (normal condition or functioning, as of a bodily organ).
• transitive verb To cause to be psychotic or otherwise severely mentally unsound.

from The Century Dictionary.

• To disturb the regular order of; throw into confusion; disconcert; disarrange: as, to derange plans or affairs.
• To disturb the state, action, or functions of; put out of proper order or condition; disorder; unsettle: as, to derange a machine; his health is much deranged; to derange one's mind or reason.
• To disorder the mind of; unsettle the reason of, as a person.
• To disarrange, displace, unsettle, confuse, embarrass, discompose, disconcert.

from the GNU version of the Collaborative International Dictionary of English.

• transitive verb To put out of place, order, or rank; to disturb the proper arrangement or order of; to throw into disorder, confusion, or embarrassment; to disorder; to disarrange.
• transitive verb To disturb in action or function, as a part or organ, or the whole of a machine or organism.
• transitive verb To disturb in the orderly or normal action of the intellect; to render insane.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• verb to cause someone to go insane (usually used in the passive, see deranged)
• verb to cause disorder in something, to distort it from its ideal state
• verb archaic to disrupt somebody's plans, to inconvenience someone

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• verb throw into great confusion or disorder
• verb derange mentally, throw out of mental balance; make insane