An acute reversible mental disorder characterized by confusion and some impairment of consciousness; generally associated with emotional labiality, hallucinations or illusions and inappropriate, impulsive, irrational or violent behavior.

Delusion of the nonexistence of the self or part of the self; also refers to an attitude of total rejection of established values or extreme skepticism regarding moral and value judgments.

Gradual or sudden deviation in train of thought without blocking; sometimes used synonymously with loosening of associations.

An acute and sometimes fatal reaction to withdrawal from alcohol, usually occurring 72 to 96 hours after the cessation of heavy drinking, distinctive characteristics are marked autonomic hyperactivity ( tachycardia, fever, hyperhidrosis, and dilated pupils), usually accompanied by tremulousness, hallucinations, illusions, and delusions.

Fundamental ego function that consists of tentative actions that test and objectively evaluate the nature and limits of the environment; includes the ability to differentiate between the external world and the internal world and to accurately judge the relation between self and the environment.

Removal of an inhibitory effect, as in the reduction of the inhibitory function of the cerebral cortex by alcohol. In psychiatry, a greater freedom to act in accordance with inner drives or feelings and with less regard for restraints dictated by cultural norms or one's superego.

Tactile hallucination involving the sensation that tiny insects are crawling over the skin. Seen in cocaine addiction and delirium tremens.

False belief based on incorrect inference about external reality, that is firmly held despite objective and obvious contradictory proof or evidence and despite the fact that other members of the culture do not share the belief.

Feigning disease to achieve a specific goal, for example, to avoid unpleasant responsibility.

A mental disorder in which the thoughts, affective response, ability to communicate and relate to others are sufficiently impaired to interfere grossly with the capacity to deal with reality; the classical characteristic of psychosis are impaired reality testing, hallucinations, delusions and illusions.

Sensation of unreality concerning oneself, parts of oneself, or ones environment that occurs under extreme stress or fatigue. Seen in schizophrenia, depersonalization disorder, schizotypal personality disorder.

Confusion , impairment of awareness of time, place, person (the position of the self in relation to other persons). Characteristic of cognitive disorders.

Unconscious defense mechanism by which the emotional component. of an unacceptable idea or object is transferred to a more acceptable one. Seen in phobias.