affect A pattern of observable behaviors that is the expression of a subjectively experienced feeling state (emotion). Common examples of affect are sadness, elation, and anger. In contrast to mood, which refers to a more pervasive and sustained emotional "climate," affect refers to more fluctuating changes in emotional "weather." What is considered the normal range of the expression of affect varies considerably, both within and among different cultures. Disturbances in affect include

• blunted Significant reduction in the intensity of emotional expression.
• flat Absence or near absence of any signs of affective expression.
• inappropriate Discordance between affective expression and the content of speech or ideation.
• labile Abnormal variability in affect with repeated, rapid, and abrupt shifts in affective expression.
• restricted or constricted Mild reduction in the range and intensity of emotional expression.
  

agitation (psychomotor agitation) Excessive motor activity associated with a feeling of inner tension. The activity is usually nonproductive and repetitious and consists of such behavior as pacing, fidgeting, wringing of the hands, pulling of clothes, and inability to sit still.

agonist medication A chemical entity extrinsic to endogenously produced substances that acts on a receptor and is capable of producing the maximal effect that can be produced by stimulating that receptor. A partial agonist is capable of producing less that the maximal effect even when given in a concentration sufficient to bind with all available receptors.

agonist/antagonist medication A chemical entity extrinsic to endogenously produced substances that acts on a family of receptors (such as mu, delta, and kappa opiate receptors) in such a fashion that it is an agonist or partial agonist on one type of receptor and an antagonist on another.

alogia An impoverishment in thinking that is inferred from observing speech and language behavior. There may be brief and concrete replies to questions and restriction in the amount of spontaneous speech (poverty of speech). Sometimes the speech is adequate in amount but conveys little information because it is overconcrete, over-abstract, repetitive, or stereotyped (poverty of content).

amnesia Loss of memory. Types of amnesia include

anterograde Loss of memory of events that occur after the onset of the etiological condition or agent.

retrograde Loss of memory of events that occurred before the onset of the etiological condition or agent.

antagonist medication A chemical entity extrinsic to endogenously produced substances that occupies a receptor, produces no physiologic effects, and prevents endogenous and exogenous chemicals from producing an effect on that receptor.

anxiety The apprehensive anticipation of future danger or misfortune accompanied by a feeling of dysphoria or somatic symptoms of tension. The focus of anticipated danger may be internal or external.

aphasia An impairment in the understanding or transmission of ideas by language in any of its forms--reading, writing, or speaking,--that is due to injury or disease of the brain centers involved in language.

aphonia An inability to prevent speech sounds that require the use of the larynx that is not due to a lesion in the central nervous system.

ataxia Partial or complete loss of coordination of voluntary muscular movement.

attention The ability to focus in a sustained manner on a particular stimulus or activity. A disturbance in attention may be manifested by easy distractibility or difficulty in finishing tasks or in concentrating on work.

avolition An inability to initiate and persist in goal-directed activities. When severe enough to be considered pathological, avolition is pervasive and prevents the person from completing many different types of activities (e.g., work, intellectual pursuits, self-care).

catalepsy Waxy flexibility--rigid maintenance of a body position over an extended period of time.

cataplexy Episodes of sudden bilateral loss of muscle tone resulting in the individual collapsing, often in association with intense emotions such as laughter, anger, fear or surprise.

catatonic behavior Marked motor abnormalities including motoric immobility (i.e., catalepsy or stupor), certain types of excessive motor activity (apparently purposeless agitation not influenced by external stimuli), extreme negativism (apparent motiveless resistance to instructions or attempts to be moved), or mutism, posturing or stereotyped movements, and echolalia or echopraxia.

conversion symptom A loss of, or alteration in, voluntary motor or sensory functioning suggesting a neurological or general medical condition. Psychological factors are judged to be associated with the development of the symptom, and the symptom is not fully explained by a neurological or general medical condition or the direct effects of a substance. The symptom is not intentionally produced or feigned and is not culturally sanctioned.

defense mechanism Automatic psychological process that protects the individual against anxiety and from awareness of internal or external stressors or dangers. Defense mechanisms mediate the individual's reaction to emotional conflicts and to external stressors. Some defense mechanisms (e.g., projection, splitting, and acting out) are almost invariably maladaptive. Others, such as suppression and denial, may be either maladaptive or adaptive, depending on their severity, their inflexibility, and the context in which they occur. Definitions of specific defense mechanisms and how they would be recorded using the Defensive Functioning Scale are presented on p. 751.

delusion A false belief based on incorrect inference about external reality that is firmly sustained despite what almost everyone else believes and despite what constitutes incontrovertible and obvious proof or evidence to the contrary. The belief is not one ordinarily accepted by other members of the person's culture or subculture (e.g., 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. Delusion conviction occurs on a continuum and can sometimes be inferred from an individual's behavior. It is often difficult to distinguish between a delusion and an overvalued idea (in which case the individual has an unreasonable belief or idea but does not hold it as firmly as is the case with a delusion).

Delusions are subdivided according to their content. Some of the more common types are listed below:

• bizarre A delusion that involves a phenomenon that the person's culture would regard as totally implausible.
• delusional jealousy The 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 relationship to a deity or famous person.
• mood-congruent See moo-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 being under one's own control.
• of reference A delusion whose theme is that events, objects, or other persons in one's immediate environment have a particular and unusual significance. These delusions are usually of a negative or pejorative nature, but also may be grandiose in content. This differs from an idea of reference, in which the false belief is not as firmly held nor as fully organized into a true belief.
• persecutory A delusion in which the central theme is that one (or someone to whom one is close) is being attacked, harassed, cheated, persecuted, or conspired against.
• somatic A delusion whose main content pertains to the appearance or functioning of one's body.
• thought broadcasting The delusion that one's thoughts are being broadcast out loud so that they can be perceived by others.
• thought insertion The delusion that certain of one's thoughts are not one's own, but rather are inserted into one's mind.
  

depersonalization An alteration in the perception or experience of the self so that one feels detached from, and as if one is an outside observer of, one's mental processes or body (e.g., feeling like one is in a dream).

derailment ("loosening of association") A pattern of speech in which a person's ideas slip off one track onto another that is completely unrelated or only obliquely related. In moving from one sentence or clause to another, the person shifts the topic idiosyncratically from one frame of reference to another and things may be said in juxtaposition that lack a meaningful relationship. This disturbance occurs between clauses, in contrast to incoherence, in which the disturbance is within clauses. An occasional change of topic without warning or obvious connection does not constitute derailment.

derealization An alteration in the perception or experience of the external world so that it seems strange or unreal (e.g., people may seem unfamiliar or mechanical).

disorientation Confusion about the time of day, date, or season (time), where one is (place), or who one is (person).

dissociation A disruption in the usually integrated functions of consciousness, memory, identity, or perception of the environment. The disturbance may be sudden or gradual, transient or chronic.

distractibility The inability to maintain attention, that is, the shifting from one are or topic to another with minimal provocation, or attention being drawn too frequently to unimportant or irrelevant external stimuli.

dysarthria Imperfect articulation of speech due to disturbances of muscular control.

dyskinesia Distortion of voluntary movements with involuntary muscular activity.

dyssomnia Primary disorders or sleep or wakefulness characterized by insomnia or hypersomnia as the major presenting symptom. Dyssomnias are disorders of the amount, quality, or timing of sleep.

dystonia Disordered tonicity of muscles.

echolalia The pathological, parrotlike, and apparently senseless repetition (echoing) of a word or phrase just spoken by another person.

echopraxia Repetition by imitation of the movements of another. The action is not a willed or voluntary one and has a semiautomatic and uncontrollable quality.

flashback A recurrence of a memory, feeling, or perceptual experience from the past.

flight of ideas A nearly continuous flow of accelerated speech with abrupt changes from topic to topic that are usually based on understandable associations, distracting stimuli, or plays on words. When severe, speech may be disorganized and incoherent.

gender dysphoria A persistent aversion toward some or all of those physical characteristics or social roles that connote one's own biological sex.

gender identity A person's inner conviction of being male or female.

gender role Attitudes, patterns of behavior, and personality attributes defined by the culture in which the person lives as stereotypically "masculine" or "feminine" social roles.

grandiosity An inflated appraisal of one's worth, power, knowledge, importance, or identity. When extreme, grandiosity may be of delusional proportions.

hallucination A sensory perception that has the compelling sense of reality of a true perception but that occurs without external stimulation of the relevant sensory organ. Hallucinations should be distinguished from illusions, in which an actual external stimulus is misperceived or misinterpreted. The person may or may not have insight into the fact that he or she is having a hallucination. One person with auditory hallucinations may recognize that he or she is having a false sensory experience, whereas another may be convinced that the source of the sensory experience has an independent physical reality. The term hallucination is not ordinarily applied to the false perceptions that occur during dreaming, while falling asleep (hypnagogic), or when awakening (hypnopompic). Transient hallucinatory experiences may occur in people without a mental disorder.

Types of hallucinations include

• auditory A hallucination involving the perception of sound, most commonly of voices. Some clinicians and investigators would not include these experiences perceived as coming from inside the head and would instead limit the concept of true auditory hallucinations to those sounds whose source is perceived as being external. However, as used in DSM-IV, no distinction is made as to whether the source of the voices is perceived as being inside or outside of the head.
• gustatory A hallucination involving the perception of taste (usually unpleasant).
• mood-congruent See mood-congruent psychotic features.
• mood-incongruent See mood-incongruent psychotic features.
• olfactory A hallucination involving the perception of odor, such as of burning rubber or decaying fish.
• somatic A hallucination involving the perception of a physical experience localized within the body (such as a feeling of electricity). A somatic hallucination is to be distinguished from physical sensations arising from an as-yet undiagnosed general medical condition, from hypochondriacal preoccupation with normal physical sensations, and from a tactile hallucination.
• tactile A hallucination involving the perception of being touched or of something being under one's skin. The most common tactile hallucinations are the sensation of electric shocks and formication (the sensation of something creeping or crawling on or under the skin).
• visual A hallucination involving sight, which may consist of formed images, such as of people, or of unformed images, such as flashes of light. Visual hallucinations should be distinguished from illusions, which are misperceptions of real external stimuli.
  

hyperacusis Painful sensitivity to sounds.

hypersomnia Excessive sleepiness, as evidenced by prolonged nocturnal sleep, difficulty maintaining an alert awake state during the day, or undesired daytime sleep episodes.

ideas of reference The feeling that casual incidents and external events have a particular and unusual meaning that is specific to the person. This is to be distinguished from a delusion of reference, in which there is a belief that is held with delusional conviction.

incoherence Speech or thinking that is essentially incomprehensible to others because words or phrases are joined together without a logical or meaningful connection. This disturbance occurs within clauses, in contrast to derailment, in which the disturbance is between clauses. This has sometimes been referred to as "word salad" to convey the degree of linguistic disorganization. Mildly ungrammatical constructions or idiomatic usage characteristic of particular regional or cultural backgrounds, lack of education, or low intelligence should not be considered incoherence. The term is generally not applied when there is evidence that the disturbance in speech is due to an aphasia.

insomnia A subjective complaint of difficulty falling or staying asleep or poor sleep quality. Types of insomnia include

initial insomnia Difficulty in falling asleep.

middle insomnia Awakening in the middle of the night followed by eventually falling back to sleep, but with difficulty.

terminal insomnia Awakening before one's usual waking time and being unable to return to sleep.

intersex condition A condition in which an individual shows intermingling, in various degrees, of the characteristics of each sex, including physical form, reproductive organs, and sexual behavior.

macropsia The visual perception that objects are larger than they actually are.

magical thinking The erroneous belief that one's thoughts, words, or actions will cause or prevent a specific outcome in some way that defies commonly understood laws of cause and effect. Magical thinking may be a part of normal child development.

micropsia The visual perception that objects are smaller than they actually are.

mood A pervasive and sustained emotion that colors the perception of the world. Common examples of mood include depression, elation, anger, and anxiety. In contrast to affect, which refers to more fluctuating changes in emotional "weather," mood refers to a more pervasive and sustained emotional "climate."

Types of mood include

• dysphoric An unpleasant mood, such as sadness, anxiety or irritability.
• elevated An exaggerated feeling of well-being, or euphoria or elation. A person with elevated mood may describe feeling "high," "ecstatic," "on top of the world," or "up in the clouds."
• euthymic Mood in the "normal" range, which implies the absence of depressed or elevated mood.
• expansive Lack of restraint in expressing one's feelings, frequently with an overevaluation of one's significance or importance.
• irritable Easily annoyed and provoked to anger.
  

mood-congruent psychotic features Delusions or hallucinations whose content is entirely consistent with the typical themes of a depressed or manic mood. If the mood is depressed, the content of the delusions or hallucinations would involve themes of personal inadequacy, guilt, disease, death, nihilism, or deserved punishment. The content of the delusion may include themes of persecution if these are based on self-derogatory concepts such as deserved punishment. If the mood is manic, the content of the delusions or hallucinations would involve themes of inflated worth, power, knowledge, or identity, or a special relationship to a deity or a famous person. The content of the delusion may include themes of persecution if these are based on concepts such as inflated worth or deserved punishment.

mood-incongruent psychotic features Delusions or hallucinations whose content is not consistent with the typical themes of a depressed or manic mood. In the case of depression, the delusions or hallucinations would not involve themes of personal inadequacy, guilt, disease, death, nihilism, or deserved punishment. In the case of mania, the delusions or hallucinations would not involve themes of inflated worth, power, knowledge, or identity, or a special relationship to a deity or a famous person. Examples of mood-incongruent psychotic features include persecutory delusions (without self-derogatory or grandiose content), thought insertion, thought broadcasting, and delusions of being controlled whose content has no apparent relationship to any of the themes listed above.

nystagmus Involuntary rhythmic movements of the eyes that consist of small-amplitude rapid tremors in one direction and a larger, slower, recurrent sweep in the opposite direction. Nystagmus may be horizontal, vertical, or rotary.

overvalued idea An unreasonable and sustained belief that is maintained with less than delusional intensity (i.e., the person is able to acknowledge the possibility that the belief may not be true). The belief is not one that is ordinarily accepted by other members of the person's culture or subculture.

panic attacks Discrete periods of sudden onset of intense apprehension, fearfulness, or terror, often associated with feelings of impending doom. During these attacks there are symptoms such a shortness of breath or smothering sensations; palpitations, pounding heart or accelerated heart rate; chest pain or discomfort; choking; and fear of going crazy or losing control. Panic attacked may be unexpected (uncued), in which the onset of the attack is not associated with a situational trigger and instead occurs "out of the blue;" situationally bound, in which the panic attack almost invariably occurs immediately on exposure to, or in anticipation of, a situational trigger ("cue"); and situationally predisposed, in which the panic attack is more likely to occur on exposure to a situational trigger but is not invariably associated with it.

paranoid ideation Ideation, of less than delusional proportions, involving suspiciousness or the belief that one is being harassed, persecuted, or unfairly treated.

parasomnia Abnormal behavior of physiological events occurring during sleep or sleep-wake transitions.

personality Enduring patterns of perceiving, relating to, and thinking about the environment and oneself. Personality traits are prominent aspects of personality that are exhibited in a wide range of important social and personal contexts. Only when personality traits are inflexible and maladaptive and cause either significant functional impairment or subjective distress do they constitute a Personality Disorder.

phobia A persistent, irrational fear of a specific object, activity, or situation (the phobic stimulus) that results in a compelling desire to avoid it. This often leads either to avoidance of the phobic stimulus or to enduring it with dread.

pressured speech Speech that is increased in amount, accelerated, and difficult or impossible to interrupt. Usually is it also loud and emphatic. Frequently the person talks without any social stimulation and may continue to talk even though no one is listening.

prodrome An early or premonitory sign or symptom of a disorder.

psychomotor agitation See agitation.

psychomotor retardation Visible generalized slowing of movements and speech.

psychotic This term has historically received a number of different definitions, none of which has achieved universal acceptance. The narrowest definition of psychotic is restricted to delusions or prominent hallucinations, with the hallucinations occurring in the absence of insight into their pathological nature. A slightly less restrictive definition would also include prominent hallucinations that the individual realizes are hallucinatory experiences. Broader still is a definition that also includes other positive symptoms of Schizophrenia (i.e., disorganized speech, grossly disorganized or catatonic behavior). Unlike these definitions based on symptoms, the definition used in DSM-II and ICD-9 was probably far too inclusive and focused on the severity of functional impairment, so that a mental disorder was termed psychotic if it resulted in "impairment that grossly interferes with the capacity to meet ordinary demands of life." Finally, the term has been defined conceptually as a loss of ego boundaries or a gross impairment in reality testing. Based on their characteristic features, the different disorders in DSM-IV emphasize different aspects of the various definitions of psychotic.

residual phase The phase of an illness that occurs after remission of the florid symptoms or the full syndrome.

sex A person's biological status as male, female, or uncertain. Depending on the circumstances, this determination may be based on the appearance of the external genitalia or on karyotyping.

sign An objective manifestation of a pathological condition. Signs are observed by the examiner rather than reported by the affected individual.

stereotyped movements Repetitive, seemingly driven, and nonfunctional motor behavior (e.g., hand shaking or waving, body rocking, head banging, mouthing of objects, self-biting, picking at skin or body orifices, hitting one's own body).

stressor, psychosocial Any life event or life change that may be associated temporally (and perhaps casually) with the onset, occurrence, or exacerbation of a mental disorder.

stupor A state of unresponsiveness with immobility and mutism.

symptom A subjective manifestation of a pathological condition. Symptoms are reported by the affected individual rather than observed by the examiner.

syndrome A grouping of signs and symptoms, based on their frequent co-occurrence, that may suggest a common underlying pathogenesis, course, familial pattern, or treatment selection.

synesthesia A condition in which a sensory experience associated with one modality occurs when another modality is stimulated, for example, a sound produces the sensation of a particular color.

tic An involuntary, sudden, rapid, recurrent, nonrhythmic, stereotyped motor movement or vocalization.

transsexualism Severe gender dysphoria, coupled with a persistent desire for the physical characteristics and social roles that connote the opposite biological sex.