cataplexy Episodes of sudden bilateral loss of muscle tone resulting in the individual collapsing, often occurring in association with intense emotions such as laughter, an— ger, fear, or surprise.
circadian rhythms Cyclical variations in physiological and biochemical function, level of sleep-wake activity, and emotional state. Circadian rhythms have a cycle of about 24 hours, ultradian rhythms have a cycle that is shorter than 1 day, and infmdian rhythms have a cycle that may last weeks or months.
ences, including DEPERSONALIZATION, DEREALIZATION, and DISSOCIATION; mixed sleep- wake state experiences; and thought-control experiences. Cognitive and perceptual dysregulation is a facet of the broad personality trait domain PSYCHOTICISM.
coma State of complete loss of consciousness.
Glossary of Technical Terms 819 compulsion Repetitive behaviors (e.g., hand washing, ordering, checking) or mental acts (e.g., praying, counting, repeating words silently) that the individual feels driven to perform in response to an obsession, or according to rules that must be applied rig- idly. The behaviors or mental acts are aimed at preventing or reducing anxiety or dis- tress, or preventing some dreaded event or situation; however, these behaviors or mental acts are not connected in a realistic way with what they are designed to neutral- ize or prevent or are clearly excessive.
conversion symptom A loss of, or alteration in, voluntary motor or sensory functioning, with or without apparent impairment of consciousness. The symptom is not fully ex- plained by a neurological or another medical condition or the direct effects of a sub- stance and is not intentionally produced or feigned.
deceitfulness Dishonesty and fraudulence; misrepresentation of self; embellishment or fabrication when relating events. Deceitfulness is a facet of the broad personality trait domain ANTAGONISM.
defense mechanism Mechanisms that mediate the individual’s reaction to emotional conﬂicts and to external stressors. Some defense mechanisms (e.g., projection, splitting, acting out) are almost invariably maladaptive. Others (e.g., suppression, denial) may be either maladaptive or adaptive, depending on their severity, their inﬂexibility, and the context in which they occur.
delusion A false belief based on incorrect inference about external reality that is firmly vertible and obvious proof or evidence to the contrary. The belief is not ordinarily ac- cepted by other members of the person’s culture or subculture (i.e., it is not an article of religious faith). When a false belief involves a value judgment, it is regarded as a delusion only when the judgment is so extreme as to defy credibility. Delusional conviction can sometimes be inferred from an overvalued idea (in which case the individual has an un- reasonable belief or idea but does not hold it as firmly as is the case with a delusion). De- lusions are subdivided according to their content. Common types are listed below: bizarre A delusion that involves a phenomenon that the person’s culture would re- gard as physically impossible.
delusional jealousy A delusion that one's sexual partner is unfaithful.
erotomanic A delusion that another person, usually of higher status, is in love with the individual.
grandiose A delusion of inﬂated worth, power, knowledge, identity, or special re- lationship to a deity or famous person.
mixed type Delusions of more than one type (e.g., EROTOMANIC, GRANDIOSE, PERSE-
CUTORY, SOMATIC) in which no one theme predominates.
mood-congruent See MOOD-CONGRUENT PSYCHOTIC FEATURES.
mood-incongruent See MOOD—INCONGRUENT PSYCHOTIC FEATURES.
of being controlled A delusion in which feelings, impulses, thoughts, or actions are experienced as being under the control of some external force rather than be- ing under one’s own control.