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The staff of the NYU Child Study Center has compiled this glossary to help you learn more about children’s mental health and disorders. Please scroll down or click on the appropriate letter to find an easy definition of the term you are interested in.



Adjustment disorder
A diagnostic category for maladaptive reactions to identifiable life events or circumstances.

Feelings; observable aspects of an emotional state, such as sadness, anger, or euphoria.

Forceful action against another person which may be physical, verbal, or symbolic, and is meant to cause pain. Such behavior may be hostile or destructive or it may be for self-protection.

Fear of leaving the familiar setting of one’s home; form of panic disorder.

Anorexia nervosa
Disorder marked by severe and prolonged refusal to eat, with severe weight loss, amenorrhea or impotence, disturbance of body image, and an intense fear of being obese.

Medications used to treat unipolar mood disorders (depression). They include three types: selective serotonin reuptake inhibitors (SSRIs), monoamineoxidase inhibitors (MAOs), tricylcic antidepressants.

Medications that reduce the intensity of or eliminate hallucinations and delusions.

A normal, natural emotion experienced by most human beings. However, a youth with an anxiety disorder experiences anxiety more strongly and more readily than others and has excessive worry to a degree that interferes with the rest of his or her life.

Loss of the ability to use or understand words.

Articulation Disorder
Inability or delay in producing speech appropriate to age and dialect, such as when sounds are omitted, distorted, or substituted.

The behavior of an organism that relates in an affiliative or dependent manner to another object. Attachment develops during critical periods of life and can be extinguished by lack of opportunity to relate. If this separation occurs before maturation can provide for adaptive adjustment, personality deviation can occur.

Asperger’s Disorder
Included with Autistic Disorder in the category of Pervasive Developmental Disorders, usually evident in the first years of life. Children with these disorders have difficulty in accomplishing early developmental tasks entailing language, communication, socialization, and motor behavior. These disorders are rare and appear to have genetic cause.

Attention-Deficit/Hyperactivity Disorder

A chronic behavioral disorder with three major symptoms: inattention, impulsivity, and sometimes hyperactivity.

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Behavior modification
Method of treatment used to help children change behaviors by rewarding desired behaviors and establishing consequences for undesirable ones.

Behavioral therapy
Treatment that focuses on modifying observable and, at least in principle, quantifiable behavior by systematic manipulation of the environment and behavioral variables thought to be functionally related to the behavior.

The use of instrumentation to provide information (feedback) about the body’s automatic and unconscious functions, such as blood pressure, heart rate, and “feeds back” the information to the person in a concrete form such as sounds or a graph on a computer screen. Person learns to regulate functions as he/she sees how different thoughts and actions change the feedback.

Bipolar disorder
A mood disorder characterized by varying episodes of mania, hypomania, and depression. Bipolar I disorder refers to the presence of one or more manic episodes, often preceding or following a depressive episode. Bipolar II disorder refers to the presence of one or more major depressive episodes and at least one hypomanic episode and no manic episodes.

Body Dysmorphic Disorder (BDD)
Individuals with BDD are beset by an extreme version of negative appearance concerns. BDD is characterized by a time-consuming and potentially disabling preoccupation with imagined or slight defects in one’s appearance or excessive concern with a slight physical anomaly. To meet the criteria for this diagnosis, the preoccupation must cause significant distress or impair school, persona, or social functioning.

Body image
One’s sense of self and one’s body as presented to others which may include size, shape, and attractiveness.

The attachment between parents and baby that forms the foundation of the parent-child relationships.

Brain imaging
Any technique that permits the invivo visualization of the substance of the central nervous system. These include: computerized axial tomography (CT) commonly called the CAT scan. Two other methods: positron-emission tomography (PET) and magnetic resonance imaging (MRI), based on different principles, also yield a series of two-dimensional images of brain regions.

Episodic eating binges or excessive intake of food or fluid. Characteristics are self-induced vomiting and purging following eating.

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Central nervous system (CNS)
The brain and the spinal cord.

Cognitive behavioral therapy (CBT)
Method of therapy that is generally short-term and focused on addressing specific negative thoughts and behavior which maintain an individual’s problems.

Cognitive development
Beginning in infancy, the acquisition of intelligence, conscious thought and problem-solving abilities.

Cognitive distortion
Inaccurate perception of oneself and how one is viewed by others.

The existence of more than one disorder at the same time.

Concrete thinking
Thinking characterized by immediate experience rather than abstractions.

Conduct Disorder
Disorder in which behavior exceed normal range and is socially destructive. Child does not respect authority, has little regard for the rights of others and breaks major societal rules; he/she demonstrates aggressive conduct that threatens physical harm or property damage, deceitfulness, theft, truancy or running away from home. Cause believed to be a combination of genetic vulnerability and environmental factors.

Present at birth.

Coping mechanism
Way of adjusting to environmental stress; includes both conscious and unconscious motivation.

Crisis intervention
Form of brief psychotherapy that emphasizes identification of the event precipitating the emotional crisis. Often used in hospital emergency rooms.

Cyclothymic disorder
A chronic but less severe form of a bipolar disorder that includes episodes of hypomania and several episodes of depression during a period of two years.

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Date rape
Sexual relation between partners known to each other but both partners have not consented.

An obviously erroneous idea that is firmly believed, regardless of its absurdity or challenge by logical argument.

Emotional state or mood characterized by sadness, despair, and loss of interest in usual activities.

Differential diagnosis
The consideration of which of two or more diseases with similar symptoms manifested by the patient.

Freedom to act according to one’s own feelings or drives, with less regard for restraints imposed by cultural norms or one’s own conscience.

Disorder of written expression
Specific learning disability involving written language and fine motor coordination, problems with visual memory, slowness in finding the correct word.

Disorder of attachment spatial disorientation and inability to arrange thoughts.

Disorder of parent-infant interaction characterized by the baby’s failure to thrive, gain weight, eat well and to engage in interactions expected for age.

Lack of awareness of one’s position in relation to space, time or other people; confusion.

Involuntary mental and emotional distance or separation from events resembling a self-hypnotic state.

Inability to maintain attention; shifting from one area or topic to another with minimum provocation.

Dizygotic twins
Twins who develop from two separately fertilized ova; fraternal twins.

Double depression
The co-occurrence of dysthymic disorder and a major depressive episode.

Drug dependence
Habituation to, abuse of and/or addiction to a chemical substance.

Drug interaction
The effects of two or more drugs taken simultaneously producing an alteration in the effects of either drug taken alone.

A two-person relationship.

Specific learning disability involving math calculation.

Specific learning disability involving writing.

Any disturbance of movement.

Specific learning disability involving reading, which may include reversing letters and words.

Unpleasant mood.

Dysthymic disorder
Literally means "ill-tempered." a minor depression. Diagnosis given when the person suffers from a persistent depressed mood, lasting most of the day, most of the time, over a span of two years for adults or one year for children and adolescents.

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Eating disorders
The overall term refers to a variety of disorders including anorexia nervosa, bulimia nervosa, and binge eating disorder.The common feature of all is aberrant eating behavior, often accompanied by a distorted body image. Anorexia is diagnosed when a youngster’s food restriction causes weight to drop 15% below what is normal. Bulimia nervosa and binge eating disorder are characterized by attempts to binge and/or get rid of food eaten.

Theoretical concept describing the internal mental function that enables a person to perceive needs and to adapt to the demands of reality.

Understanding how others feel.

Repeated elimination of feces by a child who is at least four years old in inappropriate places either involuntarily or intentionally.

Urination in inappropriate places at night (bed-wetting) or during the day in clothing in a child past the age of toilet training.

Study of the distribution, prevalence and control of mental disorders in a given population.

Causation, particularly in reference to disease.

Executive functions
Aspects of cognition that relate to an internal supervisor who directs a child’s thinking, establishes goals and organizes problem-solving strategies.

Expressive language
Communication involving the process of putting ideas and thoughts into words and then into speech.

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Family therapy
Treatment of more than one member of a family, based on the assumption that a problem or mental disorder in one member may be a manifestation of disorder in other members and may affect interrelationships and functioning.

Fetal alcohol syndrome
Congenital syndrome caused by exposure to alcohol in utero, characterized by mental retardation and specific physical characteristics.

Flight of ideas
A pattern of continuous and rapid speech marked by abrupt changes in topic.

Fragile X
Congenital syndrome caused by an abnormality of the X chromosome, characterized by mental retardation, specific maladaptive behaviors, and abnormal physical features.

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Gender identity
Perception of one’s self as male or female, developing in toddlerhood or early childhood, and reinforced by social experience and pubertal changes.

Related to heredity.

Diagram or map of a family, including notation of medial or psychiatric conditions in family members. Used in investigating complex relationships, family history, and multigenerational issues.

Group therapy
Application of therapeutic techniques to a group, including utilizing the reactions and interactions of the members of the group.

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A false sensory experience in which one perceives a sight, sound, touch, taste or smell that is not actually present.

A chronic maladaptive style of relating to the environment through preoccupation with shifting somatic concerns and symptoms, fear or conviction that one has a serious physical illness, seeking of medical treatment, unable to accept reassurance (somatization).

An episode of increased energy that can last for hours to days, but is not characterized by lack of touch with reality and so is not sever enough to be considered manic.

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A person’s global role in life and the perception of his/her sense of self.

Patterning of one’s behavior after that of another person.

Interpersonal therapy

A contemporary approach to the treatment of mood disorders that focuses on helping the person develop a better understanding of how the interaction of important relationships can affect mood aimed at strengthening the person’s communication and problem-solving capabilities.

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Language and speech disorders
Abnormal or delayed development of language and speech, including problems with development of expressive language, receptive language, and/or speech and articulation.

Learning disorders
A child with a learning disorder shows difficulty in acquiring age-appropriate competence in reading, mathematics, written expression or social skills. Thought to be due to variation in brain structure and function.

Longitudinal studies
Research design in which the same subjects are studied over the course of a determined period of time.

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Magical thinking
Belief that thinking equates with doing. Occurs in dreams of children or primitive people. Characterized by lack of reasonable relationship between cause and effect.

Deliberate simulation or exaggeration of an illness of disability in order to avoid an unpleasant situation.

Major depressive disorder (MDD)
A serious depression that lasts six months or longer. MDD has many similarities in both adolescents and adults: sadness, pessimism, sleep and appetite disturbances, and decreased concentration and sex drive; in adolescents, however, these symptoms can also be accompanied by anxiety and irritability.

Mood characterized by excessive elation, hyperactivity, agitation and accelerated thinking and speaking.

Mental retardation
A condition in which a person’s ability to learn and to function is more limited than others of the same age. During infancy and the toddler years, a child may be considered only a bit slow, although delays in development and in language and motor abilities is apparent. A diagnosis of mental retardation, however, is often not made until elementary school when the child has difficulty in mastering academic skills.

Monoamineoxidase Inhibitors (MAOIs)
Class of antidepressants that work by slowing the elimination of the brain’s neurotransmitters.

Monozygotic twins
Identical twins; twins who develop from a single fertilized ovum.

Mood disorder
Group of mental illness that are characterized by disturbances in mood (the sustained emotional state that affects one’s perception of the world).

Mood stabilizers
Class of medications (including lithium and various anticonvulsants) that are used to control wide emotional and behavioral swings characteristic of mood disorders such as bipolar depression.

Refusal to speak for conscious or unconscious reasons.

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Refusal to follow requests or commands with oppositional disagreement.

Chemical agents released by a neuron (nerve cell) to send a signal to the neighboring neuron; successive releases by each neighboring neuron allow for communication throughout the nervous system.

Night terrors
Harmless sleep disorder that causes the child to scream out and behave uncontrollably; usually of short duration with no memory of the event the next day.

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Obsessive Compulsive Disorder (OCD)
An anxiety disorder marked by the presence of obsessions and compulsions severe enough to interfere with the activities of daily life. Obsessions are repeated, unwanted thoughts often related to fears of contamination. Compulsions are repeated, purposeless behaviors.

Object permanence

Mental capacity, obtained by most children at around seven months, to understand that an object still exists even when it is out of sight.

Oppositional defiant disorder (ODD)
Disorder characterized by a pattern of uncooperative, defiant, and hostile behavior toward authority figures that seriously interferes with a child’s day-to-day functioning.

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Panic disorder
The recurrence of unexpected, intense anxiety attacks, with physical symptoms such as palpitations, accelerated heart rate, sweating, trembling or shaking, dizziness and shortness of breath.

Thoughts involving suspicousness or exaggerated feelings of unfair treatment or harassment.

Parent management training
Therapy in which parents are taught principles and strategies for managing their child’s behavior, including positive reinforcement (praise and tokens) and consequences and mild punishments (time-outs and the loss of privileges).

Mental traits, characteristics and styles of behavior which are stable over time.

Pervasive developmental disorder (PDD)
Category includes children who behave in egocentric ways, but do not have the language issues or meet the other criteria of Asperger’s or autistic disorder. If the disorders were compared to a virus, PDD is milder than Asperger’s or autistic disorder which are more virulent.

Persistent and irrational fear of particular objects, people, animals, or situations.

Substance lacking in medicinal value that is used in research as a point of comparison for treatments.

Play therapy
Form of psychotherapy in which a child enacts experiences or emotions through play with dolls, drawings, clay, or other toys.

Posttraumatic stress disorder (PTSD)
Disorder occurring as a result of exposure to a traumatic stressor, characterized by re-experiencing of the traumatic event through the recollection of images, thoughts and perceptions, accompanied by intense feelings of distress, lasting for at least one month.

Prediction of course, duration, and outcome.

Psychodynamic therapy
Therapy based on the assumption that a person can develop better control over his or her own behavior, choices and actions by understanding unconscious thoughts and feelings and interpersonal relationships.

Abnormal and maladaptive behavior, cognition or emotion.

Medical specialty concerned with the use of psychoactive medications to alleviate symptoms of emotional, behavioral or mental disorders.

Treatment for various emotional, behavioral or mental problems that uses communication between a trained person and a patient to bring about change and to relieve distress.

The inability to distinguish reality from non-reality and, in particular, the experience of hallucinations and delusions.

Stage of physical development when changes of sexual maturation occur and sexual reproduction first becomes possible.

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Rapid cycling
Form of bipolar disorder in which one has frequent episodes of depression or mania or a shift from one extreme to the other with no interval of normalcy; episodes last at least one week; it has been reported that they may be briefer in children, but this is controversial.

Rapid eye movement (REM)
Description of activity of closed eyes during a particular phase of deep sleep (REM sleep) during which dreams occur.

Reactive attachment disorder (RAD)
Disorder of infancy resulting from severely deficient or abusive parenting, signaled by a child’s failure to thrive, to gain weight, and to engage in the social interaction expected at his/her age.

Reading disorder
Specific learning disorder marked by difficulties in visually tracking words, visually discriminating between similar letters, or problems associating sounds with their symbols and interpreting the meaning of words.

Reality testing
Ability to evaluate the external world objectively and to differentiate adequately between it and the internal world.

Receptive language
Decoding spoken words and sentences requiring discrimination among sounds, interpretation of what is heard, and assignment of meaning to words and sentences.

Involuntary neurological response to stimulus.

Return to an earlier pattern of thinking or acting.

Regulation (emotion regulation)
The monitoring and adjustment of thoughts or behaviors that influence the nature, timing and expression of emotions.

Risk factor
Indication of a higher likelihood that one will develop a disorder.

Role modeling
Method of teaching behavior based on patterning by example.

The use of acting in therapy to teach clients alternate ways of reacting to a given situation.

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Disorder characterized by the distorted thinking associated with delusions and hallucinations. May have a gradual onset, with symptoms of withdrawal and disordered language evident over time, or it may have a sudden onset in adolescence.

Selective mutism
Selective silence in a child who speaks freely in very family circumstances but refuses to speak in specific social circumstances.

Selective serotonin reuptake inhibitors (SSRIs)
Group of medications that have been shown to be effective in the treatment of mood disorders; their mechanism of action is believed to be increasing the amount of serotonin in regions of the brain.

Separation anxiety disorder
A child is preoccupied with threats to the well-being of his or family; he or she experiences extreme anxiety when separated from home or those to whom she or he is attached.

Neurotransmitter believed to be central to such functions as sleep, sexual behavior, aggressiveness, motor activity and mood; abnormalities in serotonin have been suggested to play a role in psychiatric disorders such as schizophrenia and mood disorders.

Social anxiety disorder (school phobia)
Associated with an intense and persistent fear of situations in which one is exposed to possible scrutiny or judgment.

Social referencing
Psychological process in which a child looks to others, such as a parent, for cues on how to respond when confronted with something new or ambiguous.

Somatoform disorder
Disorder characterized by the development of physical symptoms that suggest a medical condition but are not fully explained by any medical condition.

Somatic symptoms
Physical symptoms resulting from psychiatric illness, such as fatigue, aches and pains, changes in appetite and sleep patterns.

Stranger anxiety
Normal emotional response of infants occurring around seven months upon hearing, seeing or being picked up by an unfamiliar person.

Involuntary breaks in the rhythm or fluency of speech such as repetition of syllables, prolongation of sounds and pauses in which the person seems to be struggling to make any sound at all.

Theoretical concept describing a person’s internal mental functions that are expressed in moral attitudes, conscience and sense of guilt.

The junction between two neurons (or between a neuron and a muscle or gland cell) through which nerve impulses are transmitted.

A configuration of symptoms that occur together and constitute a recognizable condition.

Systematic desensitization
Behavioral therapy technique in which the patient is presented with a graduated hierarchy of anxiety-provoking stimuli.

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A set of character traits an infant is born with; sometimes thought of as a child’s inherent disposition and the foundation of her or his personality.

Thought disorders
Disorder characterized by an impairment of thinking, including disorganized, incoherent, or vague speech, delusions, hallucinations or paranoia.

An intermittent, involuntary, spasmodic movement of a group of muscles, often without an obvious external stimulus. Vocal tic is a sound made involuntarily.

Technique used to briefly isolate a disruptive child in order to interrupt and avoid reinforcement of negative behavior.

Tourette’s disorder (TD)
Disorder characterized by multiple motor tics along with vocal tics such as grunting, humming, and tongue-clicking.

Transient tic disorder
A common tic disorder which generally appears during the early years; can occur daily for at least two weeks but for no longer than one year; child can have a series of transient tics over the course of years; if frequent may affect aspects of a child’s life.

Transitional object
Object such as a blanket, teddy bear, or toy selected by a toddler or preschool child for comfort against anxiety or distress.

Injury, physical or psychological, caused by shock, violence or abuse.

Tricyclic antidepressants
Class of medications used to treat disorders such as attention-deficit/hyperactivity disorder, tic disorders, depression, believed to work by increasing the amounts of various chemicals in the brain.

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