Schizophrenia: A severe emotional disorder of psychotic depth characteristically marked by a retreat from reality with delusion formation, HALLUCINATIONS, emotional disharmony, and regressive behavior.Schizophrenic Psychology: Study of mental processes and behavior of schizophrenics.Schizophrenia, Paranoid: A chronic form of schizophrenia characterized primarily by the presence of persecutory or grandiose delusions, often associated with hallucination.Antipsychotic Agents: Agents that control agitated psychotic behavior, alleviate acute psychotic states, reduce psychotic symptoms, and exert a quieting effect. They are used in SCHIZOPHRENIA; senile dementia; transient psychosis following surgery; or MYOCARDIAL INFARCTION; etc. These drugs are often referred to as neuroleptics alluding to the tendency to produce neurological side effects, but not all antipsychotics are likely to produce such effects. Many of these drugs may also be effective against nausea, emesis, and pruritus.Schizophrenia, Disorganized: A type of schizophrenia characterized by frequent incoherence; marked loosening of associations, or grossly disorganized behavior and flat or grossly inappropriate affect that does not meet the criteria for the catatonic type; associated features include extreme social withdrawal, grimacing, mannerisms, mirror gazing, inappropriate giggling, and other odd behavior. (Dorland, 27th ed)Schizophrenia, Childhood: An obsolete concept, historically used for childhood mental disorders thought to be a form of schizophrenia. It was in earlier versions of DSM but is now included within the broad concept of PERVASIVE DEVELOPMENT DISORDERS.Psychotic Disorders: Disorders in which there is a loss of ego boundaries or a gross impairment in reality testing with delusions or prominent hallucinations. (From DSM-IV, 1994)Schizophrenia, Catatonic: A type of schizophrenia characterized by abnormality of motor behavior which may involve particular forms of stupor, rigidity, excitement or inappropriate posture.Psychiatric Status Rating Scales: Standardized procedures utilizing rating scales or interview schedules carried out by health personnel for evaluating the degree of mental illness.Schizotypal Personality Disorder: A personality disorder in which there are oddities of thought (magical thinking, paranoid ideation, suspiciousness), perception (illusions, depersonalization), speech (digressive, vague, overelaborate), and behavior (inappropriate affect in social interactions, frequently social isolation) that are not severe enough to characterize schizophrenia.Cognition Disorders: Disturbances in mental processes related to learning, thinking, reasoning, and judgment.Schizophrenic Language: The artificial language of schizophrenic patients - neologisms (words of the patient's own making with new meanings).Neuropsychological Tests: Tests designed to assess neurological function associated with certain behaviors. They are used in diagnosing brain dysfunction or damage and central nervous system disorders or injury.Bipolar Disorder: A major affective disorder marked by severe mood swings (manic or major depressive episodes) and a tendency to remission and recurrence.Risperidone: A selective blocker of DOPAMINE D2 RECEPTORS and SEROTONIN 5-HT2 RECEPTORS that acts as an atypical antipsychotic agent. It has been shown to improve both positive and negative symptoms in the treatment of SCHIZOPHRENIA.Clozapine: A tricylic dibenzodiazepine, classified as an atypical antipsychotic agent. It binds several types of central nervous system receptors, and displays a unique pharmacological profile. Clozapine is a serotonin antagonist, with strong binding to 5-HT 2A/2C receptor subtype. It also displays strong affinity to several dopaminergic receptors, but shows only weak antagonism at the dopamine D2 receptor, a receptor commonly thought to modulate neuroleptic activity. Agranulocytosis is a major adverse effect associated with administration of this agent.Brief Psychiatric Rating Scale: A scale comprising 18 symptom constructs chosen to represent relatively independent dimensions of manifest psychopathology. The initial intended use was to provide more efficient assessment of treatment response in clinical psychopharmacology research; however, the scale was readily adapted to other uses. (From Hersen, M. and Bellack, A.S., Dictionary of Behavioral Assessment Techniques, p. 87)Delusions: A false belief regarding the self or persons or objects outside the self that persists despite the facts, and is not considered tenable by one's associates.Hallucinations: Subjectively experienced sensations in the absence of an appropriate stimulus, but which are regarded by the individual as real. They may be of organic origin or associated with MENTAL DISORDERS.Prefrontal Cortex: The rostral part of the frontal lobe, bounded by the inferior precentral fissure in humans, which receives projection fibers from the MEDIODORSAL NUCLEUS OF THE THALAMUS. The prefrontal cortex receives afferent fibers from numerous structures of the DIENCEPHALON; MESENCEPHALON; and LIMBIC SYSTEM as well as cortical afferents of visual, auditory, and somatic origin.Brain: The part of CENTRAL NERVOUS SYSTEM that is contained within the skull (CRANIUM). Arising from the NEURAL TUBE, the embryonic brain is comprised of three major parts including PROSENCEPHALON (the forebrain); MESENCEPHALON (the midbrain); and RHOMBENCEPHALON (the hindbrain). The developed brain consists of CEREBRUM; CEREBELLUM; and other structures in the BRAIN STEM.Affective Disorders, Psychotic: Disorders in which the essential feature is a severe disturbance in mood (depression, anxiety, elation, and excitement) accompanied by psychotic symptoms such as delusions, hallucinations, gross impairment in reality testing, etc.Sensory Gating: The ability of the BRAIN to suppress neuronal responses to external sensory inputs, such as auditory and visual stimuli. Sensory filtering (or gating) allows humans to block out irrelevant, meaningless, or redundant stimuli.Delirium, Dementia, Amnestic, Cognitive Disorders: Cognitive disorders including delirium, dementia, and other cognitive disorders. These may be the result of substance use, trauma, or other causes.Magnetic Resonance Imaging: Non-invasive method of demonstrating internal anatomy based on the principle that atomic nuclei in a strong magnetic field absorb pulses of radiofrequency energy and emit them as radiowaves which can be reconstructed into computerized images. The concept includes proton spin tomographic techniques.Haloperidol: A phenyl-piperidinyl-butyrophenone that is used primarily to treat SCHIZOPHRENIA and other PSYCHOSES. It is also used in schizoaffective disorder, DELUSIONAL DISORDERS, ballism, and TOURETTE SYNDROME (a drug of choice) and occasionally as adjunctive therapy in INTELLECTUAL DISABILITY and the chorea of HUNTINGTON DISEASE. It is a potent antiemetic and is used in the treatment of intractable HICCUPS. (From AMA Drug Evaluations Annual, 1994, p279)Social Adjustment: Adaptation of the person to the social environment. Adjustment may take place by adapting the self to the environment or by changing the environment. (From Campbell, Psychiatric Dictionary, 1996)Case-Control Studies: Studies which start with the identification of persons with a disease of interest and a control (comparison, referent) group without the disease. The relationship of an attribute to the disease is examined by comparing diseased and non-diseased persons with regard to the frequency or levels of the attribute in each group.Genetic Predisposition to Disease: A latent susceptibility to disease at the genetic level, which may be activated under certain conditions.Endophenotypes: Measurable biological (physiological, biochemical, and anatomical features), behavioral (psychometric pattern) or cognitive markers that are found more often in individuals with a disease than in the general population. Because many endophenotypes are present before the disease onset and in individuals with heritable risk for disease such as unaffected family members, they can be used to help diagnose and search for causative genes.Brain Mapping: Imaging techniques used to colocalize sites of brain functions or physiological activity with brain structures.Analysis of Variance: A statistical technique that isolates and assesses the contributions of categorical independent variables to variation in the mean of a continuous dependent variable.Startle Reaction: A complex involuntary response to an unexpected strong stimulus usually auditory in nature.Benzodiazepines: A group of two-ring heterocyclic compounds consisting of a benzene ring fused to a diazepine ring.Frontal Lobe: The part of the cerebral hemisphere anterior to the central sulcus, and anterior and superior to the lateral sulcus.National Institute of Mental Health (U.S.): A component of the NATIONAL INSTITUTES OF HEALTH concerned with research, overall planning, promoting, and administering mental health programs and research. It was established in 1949.Dominance, Cerebral: Dominance of one cerebral hemisphere over the other in cerebral functions.Attention: Focusing on certain aspects of current experience to the exclusion of others. It is the act of heeding or taking notice or concentrating.Temporal Lobe: Lower lateral part of the cerebral hemisphere responsible for auditory, olfactory, and semantic processing. It is located inferior to the lateral fissure and anterior to the OCCIPITAL LOBE.DibenzothiazepinesImage Processing, Computer-Assisted: A technique of inputting two-dimensional images into a computer and then enhancing or analyzing the imagery into a form that is more useful to the human observer.Memory, Short-Term: Remembrance of information for a few seconds to hours.Thinking: Mental activity, not predominantly perceptual, by which one apprehends some aspect of an object or situation based on past learning and experience.Gyrus Cinguli: One of the convolutions on the medial surface of the CEREBRAL HEMISPHERES. It surrounds the rostral part of the brain and CORPUS CALLOSUM and forms part of the LIMBIC SYSTEM.Psychoses, Substance-Induced: Psychotic organic mental disorders resulting from the toxic effect of drugs and chemicals or other harmful substance.Evoked Potentials, Auditory: The electric response evoked in the CEREBRAL CORTEX by ACOUSTIC STIMULATION or stimulation of the AUDITORY PATHWAYS.Diagnostic and Statistical Manual of Mental Disorders: Categorical classification of MENTAL DISORDERS based on criteria sets with defining features. It is produced by the American Psychiatric Association. (DSM-IV, page xxii)Cerebral Cortex: The thin layer of GRAY MATTER on the surface of the CEREBRAL HEMISPHERES that develops from the TELENCEPHALON and folds into gyri and sulchi. It reaches its highest development in humans and is responsible for intellectual faculties and higher mental functions.Perceptual Disorders: Cognitive disorders characterized by an impaired ability to perceive the nature of objects or concepts through use of the sense organs. These include spatial neglect syndromes, where an individual does not attend to visual, auditory, or sensory stimuli presented from one side of the body.Catechol O-Methyltransferase: Enzyme that catalyzes the movement of a methyl group from S-adenosylmethionone to a catechol or a catecholamine.Reality Testing: The individual's objective evaluation of the external world and the ability to differentiate adequately between it and the internal world; considered to be a primary ego function.Memory Disorders: Disturbances in registering an impression, in the retention of an acquired impression, or in the recall of an impression. Memory impairments are associated with DEMENTIA; CRANIOCEREBRAL TRAUMA; ENCEPHALITIS; ALCOHOLISM (see also ALCOHOL AMNESTIC DISORDER); SCHIZOPHRENIA; and other conditions.Reaction Time: The time from the onset of a stimulus until a response is observed.Cognition: Intellectual or mental process whereby an organism obtains knowledge.Control Groups: Groups that serve as a standard for comparison in experimental studies. They are similar in relevant characteristics to the experimental group but do not receive the experimental intervention.Electroencephalography: Recording of electric currents developed in the brain by means of electrodes applied to the scalp, to the surface of the brain, or placed within the substance of the brain.Social Perception: The perceiving of attributes, characteristics, and behaviors of one's associates or social groups.Phencyclidine: A hallucinogen formerly used as a veterinary anesthetic, and briefly as a general anesthetic for humans. Phencyclidine is similar to KETAMINE in structure and in many of its effects. Like ketamine, it can produce a dissociative state. It exerts its pharmacological action through inhibition of NMDA receptors (RECEPTORS, N-METHYL-D-ASPARTATE). As a drug of abuse, it is known as PCP and Angel Dust.Family: A social group consisting of parents or parent substitutes and children.Ego: The conscious portion of the personality structure which serves to mediate between the demands of the primitive instinctual drives, (the id), of internalized parental and social prohibitions or the conscience, (the superego), and of reality.Fluphenazine: A phenothiazine used in the treatment of PSYCHOSES. Its properties and uses are generally similar to those of CHLORPROMAZINE.Chromosomes, Human, Pair 22: A specific pair of GROUP G CHROMOSOMES of the human chromosome classification.Neural Pathways: Neural tracts connecting one part of the nervous system with another.Functional Laterality: Behavioral manifestations of cerebral dominance in which there is preferential use and superior functioning of either the left or the right side, as in the preferred use of the right hand or right foot.Polymorphism, Single Nucleotide: A single nucleotide variation in a genetic sequence that occurs at appreciable frequency in the population.Methylazoxymethanol Acetate: The aglycone of CYCASIN. It acts as a potent carcinogen and neurotoxin and inhibits hepatic DNA, RNA, and protein synthesis.Receptors, Dopamine D2: A subfamily of G-PROTEIN-COUPLED RECEPTORS that bind the neurotransmitter DOPAMINE and modulate its effects. D2-class receptor genes contain INTRONS, and the receptors inhibit ADENYLYL CYCLASES.Age of Onset: The age, developmental stage, or period of life at which a disease or the initial symptoms or manifestations of a disease appear in an individual.Postmortem Changes: Physiological changes that occur in bodies after death.Dopamine: One of the catecholamine NEUROTRANSMITTERS in the brain. It is derived from TYROSINE and is the precursor to NOREPINEPHRINE and EPINEPHRINE. Dopamine is a major transmitter in the extrapyramidal system of the brain, and important in regulating movement. A family of receptors (RECEPTORS, DOPAMINE) mediate its action.Personal Construct Theory: A psychological theory based on dimensions or categories used by a given person in describing or explaining the personality and behavior of others or of himself. The basic idea is that different people will use consistently different categories. The theory was formulated in the fifties by George Kelly. Two tests devised by him are the role construct repertory test and the repertory grid test. (From Stuart Sutherland, The International Dictionary of Psychology, 1989)Genotype: The genetic constitution of the individual, comprising the ALLELES present at each GENETIC LOCUS.Facial Expression: Observable changes of expression in the face in response to emotional stimuli.Mood Disorders: Those disorders that have a disturbance in mood as their predominant feature.Auditory Perceptual Disorders: Acquired or developmental cognitive disorders of AUDITORY PERCEPTION characterized by a reduced ability to perceive information contained in auditory stimuli despite intact auditory pathways. Affected individuals have difficulty with speech perception, sound localization, and comprehending the meaning of inflections of speech.Statistics as Topic: The science and art of collecting, summarizing, and analyzing data that are subject to random variation. The term is also applied to the data themselves and to the summarization of the data.Expressed Emotion: Frequency and quality of negative emotions, e.g., anger or hostility, expressed by family members or significant others, that often lead to a high relapse rate, especially in schizophrenic patients. (APA, Thesaurus of Psychological Index Terms, 7th ed)Contingent Negative Variation: A negative shift of the cortical electrical potentials that increases over time. It is associated with an anticipated response to an expected stimulus and is an electrical event indicative of a state of readiness or expectancy.Emotions: Those affective states which can be experienced and have arousing and motivational properties.Social Behavior: Any behavior caused by or affecting another individual, usually of the same species.Remedial Teaching: Specialized instruction for students deviating from the expected norm.Nerve Net: A meshlike structure composed of interconnecting nerve cells that are separated at the synaptic junction or joined to one another by cytoplasmic processes. In invertebrates, for example, the nerve net allows nerve impulses to spread over a wide area of the net because synapses can pass information in any direction.Acoustic Stimulation: Use of sound to elicit a response in the nervous system.Event-Related Potentials, P300: A late-appearing component of the event-related potential. P300 stands for a positive deflection in the event-related voltage potential at 300 millisecond poststimulus. Its amplitude increases with unpredictable, unlikely, or highly significant stimuli and thereby constitutes an index of mental activity. (From Campbell, Psychiatric Dictionary, 6th ed)Siblings: Persons or animals having at least one parent in common. (American College Dictionary, 3d ed)Verbal Learning: Learning to respond verbally to a verbal stimulus cue.Paranoid Disorders: Chronic mental disorders in which there has been an insidious development of a permanent and unshakeable delusional system (persecutory delusions or delusions of jealousy), accompanied by preservation of clear and orderly thinking. Emotional responses and behavior are consistent with the delusional state.Hippocampus: A curved elevation of GRAY MATTER extending the entire length of the floor of the TEMPORAL HORN of the LATERAL VENTRICLE (see also TEMPORAL LOBE). The hippocampus proper, subiculum, and DENTATE GYRUS constitute the hippocampal formation. Sometimes authors include the ENTORHINAL CORTEX in the hippocampal formation.Psychometrics: Assessment of psychological variables by the application of mathematical procedures.Risk Factors: An aspect of personal behavior or lifestyle, environmental exposure, or inborn or inherited characteristic, which, on the basis of epidemiologic evidence, is known to be associated with a health-related condition considered important to prevent.Severity of Illness Index: Levels within a diagnostic group which are established by various measurement criteria applied to the seriousness of a patient's disorder.Dyskinesia, Drug-Induced: Abnormal movements, including HYPERKINESIS; HYPOKINESIA; TREMOR; and DYSTONIA, associated with the use of certain medications or drugs. Muscles of the face, trunk, neck, and extremities are most commonly affected. Tardive dyskinesia refers to abnormal hyperkinetic movements of the muscles of the face, tongue, and neck associated with the use of neuroleptic agents (see ANTIPSYCHOTIC AGENTS). (Adams et al., Principles of Neurology, 6th ed, p1199)Theory of Mind: The ability to attribute mental states (e.g., beliefs, desires, feelings, intentions, thoughts, etc.) to self and to others, allowing an individual to understand and infer behavior on the basis of the mental states. Difference or deficit in theory of mind is associated with ASPERGER SYNDROME; AUTISTIC DISORDER; and SCHIZOPHRENIA, etc.Neuregulin-1: A peptide factor originally identified by its ability to stimulate the phosphorylation the erbB-2 receptor (RECEPTOR, ERBB-2). It is a ligand for the erbB-3 receptor (RECEPTOR, ERBB-3) and the erbB-4 receptor. Variant forms of NEUREGULIN-1 occur through alternative splicing of its mRNA.Mental Disorders: Psychiatric illness or diseases manifested by breakdowns in the adaptational process expressed primarily as abnormalities of thought, feeling, and behavior producing either distress or impairment of function.Inhibition (Psychology): The interference with or prevention of a behavioral or verbal response even though the stimulus for that response is present; in psychoanalysis the unconscious restraining of an instinctual process.Psychomotor Performance: The coordination of a sensory or ideational (cognitive) process and a motor activity.Paternal Age: Age of the biological father.Anhedonia: Inability to experience pleasure due to impairment or dysfunction of normal psychological and neurobiological mechanisms. It is a symptom of many PSYCHOTIC DISORDERS (e.g., DEPRESSIVE DISORDER, MAJOR; and SCHIZOPHRENIA).Rehabilitation, Vocational: Training of the mentally or physically disabled in work skills so they may be returned to regular employment utilizing these skills.Affective Symptoms: Mood or emotional responses dissonant with or inappropriate to the behavior and/or stimulus.Functional Neuroimaging: Methods for visualizing REGIONAL BLOOD FLOW, metabolic, electrical, or other physiological activities in the CENTRAL NERVOUS SYSTEM using various imaging modalities.Nerve Tissue ProteinsSocial Environment: The aggregate of social and cultural institutions, forms, patterns, and processes that influence the life of an individual or community.Diseases in Twins: Disorders affecting TWINS, one or both, at any age.Intelligence: The ability to learn and to deal with new situations and to deal effectively with tasks involving abstractions.Phenotype: The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.Reference Values: The range or frequency distribution of a measurement in a population (of organisms, organs or things) that has not been selected for the presence of disease or abnormality.Prenatal Exposure Delayed Effects: The consequences of exposing the FETUS in utero to certain factors, such as NUTRITION PHYSIOLOGICAL PHENOMENA; PHYSIOLOGICAL STRESS; DRUGS; RADIATION; and other physical or chemical factors. These consequences are observed later in the offspring after BIRTH.Hospitals, Psychiatric: Special hospitals which provide care to the mentally ill patient.Psychoanalytic Therapy: A form of psychiatric treatment, based on Freudian principles, which seeks to eliminate or diminish the undesirable effects of unconscious conflicts by making the patient aware of their existence, origin, and inappropriate expression in current emotions and behavior.Psychopathology: The study of significant causes and processes in the development of mental illness.Personality Development: Growth of habitual patterns of behavior in childhood and adolescence.Receptors, Dopamine: Cell-surface proteins that bind dopamine with high affinity and trigger intracellular changes influencing the behavior of cells.Cognitive Therapy: A direct form of psychotherapy based on the interpretation of situations (cognitive structure of experiences) that determine how an individual feels and behaves. It is based on the premise that cognition, the process of acquiring knowledge and forming beliefs, is a primary determinant of mood and behavior. The therapy uses behavioral and verbal techniques to identify and correct negative thinking that is at the root of the aberrant behavior.Chronic Disease: Diseases which have one or more of the following characteristics: they are permanent, leave residual disability, are caused by nonreversible pathological alteration, require special training of the patient for rehabilitation, or may be expected to require a long period of supervision, observation, or care. (Dictionary of Health Services Management, 2d ed)Basal Ganglia Diseases: Diseases of the BASAL GANGLIA including the PUTAMEN; GLOBUS PALLIDUS; claustrum; AMYGDALA; and CAUDATE NUCLEUS. DYSKINESIAS (most notably involuntary movements and alterations of the rate of movement) represent the primary clinical manifestations of these disorders. Common etiologies include CEREBROVASCULAR DISORDERS; NEURODEGENERATIVE DISEASES; and CRANIOCEREBRAL TRAUMA.Genetic Association Studies: The analysis of a sequence such as a region of a chromosome, a haplotype, a gene, or an allele for its involvement in controlling the phenotype of a specific trait, metabolic pathway, or disease.Amphetamine: A powerful central nervous system stimulant and sympathomimetic. Amphetamine has multiple mechanisms of action including blocking uptake of adrenergics and dopamine, stimulation of release of monamines, and inhibiting monoamine oxidase. Amphetamine is also a drug of abuse and a psychotomimetic. The l- and the d,l-forms are included here. The l-form has less central nervous system activity but stronger cardiovascular effects. The d-form is DEXTROAMPHETAMINE.Receptors, N-Methyl-D-Aspartate: A class of ionotropic glutamate receptors characterized by affinity for N-methyl-D-aspartate. NMDA receptors have an allosteric binding site for glycine which must be occupied for the channel to open efficiently and a site within the channel itself to which magnesium ions bind in a voltage-dependent manner. The positive voltage dependence of channel conductance and the high permeability of the conducting channel to calcium ions (as well as to monovalent cations) are important in excitotoxicity and neuronal plasticity.Verbal Behavior: Includes both producing and responding to words, either written or spoken.