A
Abnormal psychology: The subfield of psychology that addresses the causes and progression of psychological disorders; also referred to as psychopathology.
Abstinence violation effect: The result of violating a self-imposed rule about food restriction, which leads to feeling out of control with food, which then leads to overeating.
Action potential: The wave of chemical activity that moves from the cell body down the axon when a neuron fires.
Active phase: The phase of a psychological disorder (such as schizophrenia) in which the person exhibits symptoms that meet the criteria for the disorder.
Acute stress disorder: A traumatic stress disorder that involves (a) intrusive re-experiencing of the traumatic event, (b) avoidance of stimuli related to the event, (c) negative changes in thought and mood, (d) dissociation, and (e) hyperarousal and reactivity, with these symptoms lasting for less than a month.
Affect: An emotion that is associated with a particular idea or behavior, similar to an attitude.
Age cohort: A group of people born in a particular range of years.
Agoraphobia: An anxiety disorder characterized by persistent avoidance of situations that might trigger panic symptoms or from which help would be difficult to obtain.
Allegiance effect: A pattern in which studies conducted by investigators who prefer a particular theoretical orientation tend to obtain data that supports that particular orientation.
Alzheimer’s disease: A medical condition in which the afflicted person initially has problems with both memory and executive function and which leads to progressive dementia.
American Legal Institute (ALI) test: The legal test in which a defendant is considered insane if he or she either lacks a substantial capacity to appreciate that his or her behavior was wrong or has a diminished ability to make his or her behavior conform to the law.
Amnesia: Memory loss, which in dissociative disorders is usually temporary but, in rare cases, may be permanent.
Amyloid plaques: Fragments of protein that accumulate on the outside surfaces of neurons, particularly neurons in the hippocampus.
Anhedonia: A difficulty or inability to experience pleasure.
Anorexia nervosa: An eating disorder characterized by significantly low body weight along with an intense fear of gaining weight or using various methods to prevent weight gain.
Antabuse: A medication for treating alcohol use disorder that induces violent nausea and vomiting when it is mixed with alcohol.
Antisocial personality disorder: A personality disorder diagnosed in adulthood characterized by a persistent disregard for the rights of others.
Anxiety: A sense of agitation or nervousness, which is often focused on an upcoming possible danger.
Anxiety disorder: A category of psychological disorders in which the primary symptoms involve fear, extreme anxiety, intense arousal, and/or extreme attempts to avoid stimuli that lead to fear and anxiety.
Aphasia: A neurological condition characterized by problems in producing or comprehending language.
Applied behavior analysis: A technique used to modify maladaptive behaviors by reinforcing new behaviors through shaping.
Apraxia: A neurological condition characterized by problems in organizing and carrying out voluntary movements even though the muscles themselves are not impaired.
Asylums: Institutions to house and care for people who are afflicted with mental illness.
Attention-deficit/hyperactivity disorder (ADHD): A disorder that typically arises in childhood and is characterized by inattention, hyperactivity, and/or impulsivity.
Attrition: The reduction in the number of participants during a research study.
Atypical antipsychotics: A relatively new class of antipsychotic medications that affects dopamine and serotonin activity; also referred to as second-generation antipsychotics.
Autism spectrum disorder (ASD): A neurodevelopmental disorder characterized by deficits in communication and social interaction skills, as well as stereotyped behaviors and narrow interests.
Avoidant personality disorder: A personality disorder characterized by extreme shyness that usually stems from feeling inadequate and being overly sensitive to negative evaluation.
Avolition: A negative symptom of schizophrenia marked by difficulty initiating or following through with activities.
B
Behavior therapy: The form of treatment that rests on the ideas that: (1) maladaptive behaviors stem from previous learning, and (2) new learning can allow patients to develop more adaptive behaviors, which in turn can change cognitions and emotions.
Behavioral genetics: The field that investigates the degree to which the variability of characteristics in a population arises from genetic versus environmental factors.
Behaviorism: An approach to psychology that focuses on understanding directly observable behaviors in order to understand mental illness and other psychological phenomena.
Bias: A tendency that distorts data.
Binge eating: Eating much more food at one time than most people would eat in the same period of time or context.
Binge eating disorder: An eating disorder characterized by binge eating without subsequent purging.
Biofeedback: A technique in which a person is trained to bring normally involuntary or unconscious bodily activity, such as heart rate or muscle tension, under voluntary control.
Biological marker: A neurological, bodily, or behavioral characteristic that distinguishes people with a psychological disorder (or a first-degree relative with the disorder) from those without the disorder.
Biopsychosocial approach: The view that a psychological disorder arises from the combined influences of three types of factors—biological, psychological, and social.
Bipolar disorders: Mood disorders in which a person’s mood is often persistently and abnormally upbeat or shifts inappropriately from upbeat to markedly down.
Body dysmorphic disorder: A disorder characterized by excessive preoccupation with a perceived defect or defects in appearance and repetitive behaviors to hide the perceived defect.
Borderline personality disorder: A personality disorder characterized by volatile emotions, an unstable self-image, and impulsive behavior in relationships.
Brain circuits: Sets of connected neurons that work together to accomplish a basic process.
Brain systems: Sets of brain circuits that work together to accomplish a complex function.
Brief psychotic disorder: A psychotic disorder characterized by the sudden onset of positive or disorganized symptoms that last between 1 day and 1 month and are followed by full recovery.
Brocas aphasia: A neurological condition characterized by problems producing speech.
Bulimia nervosa: An eating disorder characterized by binge eating along with vomiting or other behaviors to compensate for the large number of calories ingested.
C
Case studies (in studies of psychopathology): A research method that focuses in detail on one individual and the factors that underlie that person’s psychological disorder or disorders.
Catatonia: A condition in which a person does not respond to the environment or remains in an odd posture or position, with rigid muscles, for hours.
Cerebral cortex: The outer layer of cells on the surface of the brain.
Civil commitment: The involuntary commitment to a mental health facility of a person deemed to be at significant risk of harming himself or herself or a specific other person.
Classical conditioning: A type of learning that occurs when two stimuli are paired so that a neutral stimulus becomes associated with another stimulus that elicits a reflexive behavior; also referred to as Pavlovian conditioning.
Clinical assessment: The process of obtaining relevant information and making a judgment about mental illness based on the information.
Clinical interview: A meeting between clinician and patient during which the clinician asks questions related to the patient’s symptoms and functioning.
Clinical psychologist: A mental health professional who has a doctoral degree that requires several years of related coursework and several years of treating patients while receiving supervision from experienced clinicians.
Cluster A personality disorders: Personality disorders characterized by odd or eccentric behaviors that have elements related to those of schizophrenia.
Cluster B personality disorders: Personality disorders characterized by emotional, dramatic, or erratic behaviors that involve problems with emotional regulation.
Cluster C personality disorders: Personality disorders characterized by anxious or fearful behaviors.
Cognitive-behavior therapy (CBT): The form of treatment that combines methods from cognitive and behavior therapies.
Cognitive distortions: Dysfunctional, maladaptive thoughts that are not accurate reflections of reality and contribute to psychological disorders.
Cognitive therapy: The form of treatment that rests on the ideas that: (1) mental contents influence feelings and behavior; (2) irrational thoughts and incorrect beliefs lead to psychological problems; and (3) correcting such thoughts and beliefs will therefore lead to better mood and more adaptive behavior.
Common factors: Helpful aspects of therapy that are shared by virtually all types of psychotherapy.
Common liabilities model: The model that explains how neurological, psychological, and social factors make a person vulnerable to a variety of problematic behaviors, including substance use disorders; also called problem behavior theory.
Community care: Programs that allow mental health care providers to visit patients in their homes at any time of the day or night; also known as assertive community treatment.
Comorbidity: The presence of more than one disorder at the same time in a given patient.
Competency to stand trial: The mental state during the time leading up to the trial enables him or her to participate in his or her own defense.
Complex inheritance: The transmission of traits that are expressed along a continuum by the interaction of sets of genes.
Compulsions: Repetitive behaviors or mental acts that a person feels driven to carry out and that usually must be performed according to rigid “rules” or correspond thematically to an obsession.
Computerized axial tomography (CT): A neuroimaging technique that uses X-rays to build a three-dimensional image (CT or CAT scan) of the brain.
Concordance rate: The probability that both twins will have a characteristic or disorder, given that one of them has it.
Conditioned emotional responses: Emotions and emotion-related behaviors that are classically conditioned.
Conditioned response (CR): A response that comes to be elicited by the previously neutral stimulus that has become a conditioned stimulus.
Conditioned stimulus (CS): A neutral stimulus that, when paired with an unconditioned stimulus, comes to elicit the reflexive behavior.
Conduct disorder: A disorder that typically arises in childhood and is characterized by the violation of the basic rights of others or of societal norms that are appropriate to the person’s age.
Confidentiality: The ethical requirement not to disclose information about a patient (even whether someone is a patient) to others unless legally compelled to do so.
Confounding variables: Factors that might inadvertently affect the variables of interest in an experiment.
Contingency management: A procedure for modifying behavior by changing the conditions that led to, or are produced by, it.
Control group: A group of participants in an experiment for which the independent variable is not manipulated, but which is otherwise treated identically to the experimental group.
Conversion disorder: A somatic symptom disorder that involves sensory or motor symptoms that are incompatible with known neurological and medical conditions.
Correlation: The relationship between the measurements of two variables in which a change in the value of one variable is associated with a change in the value of the other variable.
Correlation coefficient: A number that quantifies the strength of the correlation between two variables; the correlation coefficient is most typically symbolized by r.
Counseling psychologist: A mental health professional who has either a Ph.D. degree from a psychology program that focuses on counseling or an Ed.D. degree from a school of education.
Criminal commitment: The involuntary commitment to a mental health facility of a person charged with a crime.
Criminally responsible: The determination that a defendant’s crime was the product of both an action or attempted action (the alleged criminal behavior) and his or her intention to perform that action.
Crystallized intelligence: A type of intelligence that relies on using knowledge to reason in familiar ways; such knowledge has “crystallized” from previous experience.
Culture: The shared norms and values of a society that are explicitly and implicitly conveyed to its members by example and through the use of reward and punishment.
Cyclothymic disorder: A mood disorder characterized by chronic, fluctuating mood disturbance with numerous periods of hypomanic symptoms alternating with depressive symptoms, each of which does not meet the criteria for its respective mood episodes.
D
Dangerousness: The legal term that refers to someone’s potential to harm self or others.
Data: Methodical observations, which include numerical measurements of phenomena.
Defense mechanisms: Unconscious processes that work to transform psychological conflict in order to prevent unacceptable thoughts and feelings from reaching consciousness.
Delayed ejaculation: A sexual dysfunction characterized by a man’s delay or absence of orgasm.
Delirium: A neurocognitive disorder characterized by a relatively sudden disturbance in attention and awareness as well as disruption of at least one other aspect of cognitive functioning.
Delirium tremens (DTs): The symptoms of alcohol withdrawal that include uncontrollable shaking, confusion, convulsions, visual hallucinations, and fever.
Delusional disorder: A psychotic disorder characterized by the presence of delusions that have persisted for more than 1 month.
Delusions: Persistent false beliefs that are held despite evidence that the beliefs are incorrect or exaggerate reality.
Dementia: A set of neurocognitive disorders characterized by deficits in learning new information or recalling information already learned plus at least one other type of cognitive impairment.
Dependent personality disorder: A personality disorder characterized by submissive and clingy behaviors, based on fear of separation.
Dependent variable: A variable that is measured and that may change its values as a result of manipulating the independent variable.
Depersonalization: A dissociative symptom in which the perception or experience of self—either one’s body or one’s mental processes—is altered to the point that the person feels like an observer, as though seeing oneself from the “outside.”
Depersonalization-derealization disorder: A dissociative disorder, the primary symptom of which is a persistent feeling of being detached from one’s mental processes, body, or surroundings.
Derealization: A dissociative symptom in which the external world is perceived or experienced as strange or unreal.
Detoxification: Medically supervised discontinuation of substances for those with substance use disorders; also referred to as detox.
Diagnosis: The identification of the nature of a disorder.
Diagnostic bias: A systematic error in diagnosis.
Dialectical behavior therapy (DBT): A form of treatment that includes elements of CBT as well as an emphasis on validating the patient’s experience, a Zen Buddhist approach, and a dialectics component.
Diathesis–stress model: A model that rests on the idea that a psychological disorder is triggered when a person with a predisposition—a diathesis—for the particular disorder experiences an environmental event that causes significant stress.
Disruptive mood dysregulation disorder (DMDD): A depressive disorder in children characterized by persistent irritability and frequent episodes of out-of-control behavior.
Dissociation: The separation of mental processes—such as perception, memory, and self-awareness—that are normally integrated.
Dissociative amnesia: A dissociative disorder in which the sufferer has significantly impaired memory for important experiences or personal information that cannot be explained by ordinary forgetfulness.
Dissociative disorders: A category of psychological disorders in which consciousness, memory, emotion, perception, body representation, motor control, or identity are dissociated to the point where the symptoms are pervasive, cause significant distress, and interfere with daily functioning.
Dissociative identity disorder (DID): A dissociative disorder characterized by the presence of two or more distinct personality states, or an experience of possession trance, which gives rise to a discontinuity in the person’s sense of self and agency.
Dizygotic twins: Twins who developed from two fertilized eggs and so have the same overlap in genes (50%) as do siblings not conceived at the same time; also referred to as fraternal twins.
Dopamine reward system: The system of neurons, primarily in the nucleus accumbens and ventral tegmental area, that relies on dopamine and gives rise to pleasant feelings.
Dose–response relationship: The association between more treatment (a higher dose) and greater improvement (a better response).
Double-blind design: A research design in which neither the participant nor the investigator’s assistant knows the group to which specific participants have been assigned or the predicted results of the study.
Drug cues: The stimuli associated with drug use that come to elicit conditioned responses through their repeated pairings with use of the drug.
Durham test: The legal test in which a person is considered insane if an irresistible impulse to perform criminal behavior was due to a mental defect or disorder present at the time of the crime.
Dyslexia: A learning disorder characterized by difficulty with reading accuracy, speed, or comprehension that interferes with academic achievement or activities of daily functioning that involve reading.
E
Eating disorder: A category of psychological disorders characterized by abnormal eating and a preoccupation with body image.
Ego: According to Freud, the psychic structure that is charged with mediating between the id’s demands for immediate gratification and the superego’s high standards of morality, as well as the constraints of external reality.
Electroconvulsive therapy (ECT): A procedure that sends electrical pulses into the brain to cause a controlled brain seizure, in an effort to reduce or eliminate the symptoms of certain psychological disorders.
Emotion: A short-lived experience evoked by a stimulus that produces a mental response, a typical behavior, and a positive or negative subjective feeling.
Epidemiology: The type of correlational research that investigates the rate of occurrence, the possible causes and risk factors, and the course of diseases or disorders.
Erectile disorder: A sexual dysfunction characterized by a man’s persistent difficulty obtaining or maintaining an adequate erection until the end of sexual activity, or a decrease in erectile rigidity; sometimes referred to as impotence.
Etiology: The factors that lead a person to develop a psychological disorder.
Executive functions: Mental processes involved in planning, organizing, problem solving, abstract thinking, and exercising good judgment.
Exhibitionistic disorder: A paraphilic disorder in which sexual fantasies, urges, or behaviors involve exposing one’s genitals to an unsuspecting person.
Expansive mood: A mood that involves unceasing, indiscriminate enthusiasm for interpersonal or sexual interactions or for projects.
Experimenter expectancy effect: The investigator’s intentionally or unintentionally treating participants in ways that encourage particular types of responses.
Experiments: Research studies in which investigators intentionally manipulate one variable at a time, and measure the consequences of such manipulation on one or more other variables.
Exposure: A behavioral technique that involves repeated contact with a feared or arousing stimulus in a controlled setting, bringing about habituation.
Exposure with response prevention: A behavioral technique in which a patient is carefully prevented from engaging in his or her usual maladaptive response after being exposed to a stimulus that usually elicits the response.
External validity: A characteristic of a study that indicates that the results generalize from the sample to the population from which it was drawn and from the conditions used in the study to relevant conditions outside the study.
F
Factitious disorder: A psychological disorder marked by the false reporting or inducing of medical or psychological symptoms in order to receive attention.
Family therapy: A treatment that involves an entire family or some portion of a family.
Female orgasmic disorder: A sexual dysfunction characterized by a woman’s normal sexual excitement not leading to orgasm or to her having diminished intensity of sensations of orgasm.
Female sexual interest/arousal disorder: A sexual dysfunction characterized by a woman’s persistent or recurrent lack of or reduced sexual interest or arousal; formerly referred to as frigidity.
Fetishistic disorder: A paraphilic disorder in which the person repeatedly uses nonliving objects or nongenital body parts to achieve or maintain sexual arousal and such an arousal pattern causes significant distress or impairs functioning.
Fight-or-flight response: The automatic neurological and bodily response to a perceived threat; also called the stress response.
Flat affect: A lack of, or considerably diminished, emotional expression, such as occurs when someone speaks robotically and shows little facial expression.
Flight of ideas: Thoughts that race faster than they can be said.
Fluid intelligence: A type of intelligence that relies on the ability to create novel strategies to solve new problems, without relying solely on familiar approaches.
Frotteuristic disorder: A paraphilic disorder in which recurrent, intense, sexually arousing fantasies, sexual urges, or behaviors involve touching or rubbing against a nonconsenting person.
Functional magnetic resonance imaging (fMRI): A neuroimaging technique that uses MRI to obtain images of brain functioning, which reveal the extent to which different brain areas are activated during particular tasks.
G
Gateway hypothesis: The proposal that use can become a use disorder when “entry” drugs serve as a gateway to (or the first stage in a progression to) use of “harder” drugs.
Gender dysphoria: A psychological disorder characterized by an incongruence between a person’s assigned gender at birth and the subjective experience of his or her gender, and that incongruence causes distress.
Gender identity: The subjective sense of being male or female (or having the sense of a more fluid identity, outside the binary categories of male and female), as these categories are defined by a person’s culture.
Gender role: The outward behaviors, attitudes, and traits that a culture deems masculine or feminine.
Generalized anxiety disorder (GAD): An anxiety disorder characterized by uncontrollable worry and anxiety about a number of events or activities, which are not solely the result of another disorder.
Genes: Segments of DNA that control the production of particular proteins and other substances.
Genito-pelvic pain/penetration disorder: A sexual dysfunction in women characterized by pain, fear, or anxiety related to the vaginal penetration of intercourse.
Genotype: The sum of an organism’s genes.
H
Habituation: The process by which the emotional response to a stimulus that elicits fear or anxiety is reduced by exposing the patient to the stimulus repeatedly.
Hallucinations: Sensations that are so vivid that the perceived objects or events seem real, although they are not. Hallucinations can occur in any of the five senses.
Heritability: An estimate of how much of the variation in a characteristic within a population (in a specific environment) can be attributed to genetics.
High expressed emotion (high EE): A family interaction style characterized by hostility, unnecessary criticism, or emotional overinvolvement.
Histrionic personality disorder: A personality disorder characterized by attention-seeking behaviors and exaggerated and dramatic displays of emotion.
Hoarding disorder: An obsessive-compulsive-related disorder characterized by persistent difficulty throwing away or otherwise parting with possessions—to the point that the possessions impair daily life, regardless of the value of those possessions.
Hormones: Chemicals that are released directly into the bloodstream that activate or alter the activity of neurons.
Huntington’s disease: A progressive disease that kills neurons and affects cognition, emotion, and motor functions; it leads to dementia and eventually results in death.
Hypersomnia: Sleeping more hours each day than normal.
Hypervigilance: A heightened search for threats.
Hypothesis: A preliminary idea that is proposed to answer a question about a set of observations.
Hysteria: An emotional condition marked by extreme excitability and bodily symptoms for which there is no medical explanation.
I
Id: According to Freud, the seat of sexual and aggressive drives, as well as of the desire for immediate gratification of physical and psychological needs.
Identity problem: A dissociative symptom in which a person is not sure who he or she is or may assume a new identity.
Illness anxiety disorder: A somatic symptom disorder marked by a preoccupation with a fear or belief of having a serious disease in the face of either no or minor medical symptoms and excessive behaviors related to this belief.
Inappropriate affect: An expression of emotion that is not appropriate to what a person is saying or to the situation.
Inclusion: The placement of students with disabilities in a regular classroom, with guidelines for any accommodations that the regular classroom teacher or special education teacher should make.
Independent variable: A variable that a researcher manipulates.
Intellectual disability: A neurodevelopmental disorder characterized by cognitive abilities that are significantly below normal, along with impaired adaptive functioning in daily life; also called intellectual developmental disorder and previously referred to as mental retardation.
Internal validity: A characteristic of a study that indicates that it measures what it purports to measure because it has controlled for confounds.
Interoceptive exposure: A behavioral therapy method in which patients intentionally elicit the bodily sensations associated with panic so that they can habituate to those sensations and not respond with fear.
Interpersonal therapy (IPT): The form of treatment that is intended to improve the patient’s skills in relationships so that they become more satisfying.
In vivo exposure: A behavioral therapy method that consists of direct exposure to a feared or avoided situation or stimulus.
Irresistible impulse test: The legal test in which a person is considered insane if he or she knew that his or her criminal behavior was wrong but nonetheless performed it because of an irresistible impulse.
L
Labile affect: Affect that changes inappropriately rapidly.
Learned helplessness: The state of “giving up” that arises when an animal or person is in an aversive situation where it seems that no action can be effective.
Lithium: The oldest mood stabilizer.
Longitudinal studies (in studies of psychopathology): Research studies that are designed to determine whether a given variable is a risk factor by using data collected from the same participants at various points in time.
M
Magnetic resonance imaging (MRI): A neuroimaging technique that creates especially sharp images of the brain by measuring the magnetic properties of atoms in the brain.
Major depressive disorder (MDD): A mood disorder marked by five or more symptoms of an MDE lasting more than 2 weeks.
Major depressive episode (MDE): A mood episode characterized by severe depression that lasts at least 2 weeks.
Major neurocognitive disorder: A neurocognitive disorder characterized by evidence of a substantial decline in at least one cognitive domain, and impaired daily functioning.
Male hypoactive sexual desire disorder: A sexual dysfunction characterized by a persistent or recurrent lack of erotic or sexual fantasies or an absence of desire for sexual activity.
Malingering: Intentional false reporting of symptoms or exaggeration of existing symptoms, either for material gain or to avoid unwanted events.
Manic episode: A period of at least 1 week characterized by abnormally increased energy or activity and abnormal and persistent euphoria or expansive mood or irritability.
Maudsley approach: A family treatment for anorexia nervosa that focuses on supporting parents as they determine how to lead their child to eat appropriately.
Mental contents: The specific material that is stored in the mind and operated on by mental processes.
Mental processes: The internal operations that underlie cognitive and emotional functions (such as perception, memory, and guilt feelings) and most human behavior.
Meta-analysis: A research method that statistically combines the results of a number of studies that address the same question to determine the overall effect.
Mild neurocognitive disorder: A neurocognitive disorder characterized by a modest decline from baseline in at least one cognitive domain, but that decline is not enough to interfere with daily functioning.
Monoamine oxidase inhibitors (MAOIs): Antidepressant medications that increase the amount of monoamine neurotransmitter in synapses.
Monozygotic twins: Twins who have basically the same genetic makeup because they began life as a single fertilized egg (zygote), which then divided into two embryos; also referred to as identical twins.
Mood: A persistent emotion that is not attached to a stimulus; it exists in the background and influences mental processes, mental contents, and behavior.
Mood disorders: Psychological disorders characterized by prolonged and marked disturbances in mood that affect how people feel, what they believe and expect, how they think and talk, and how they interact with others.
Mood stabilizer: A category of medication that minimizes mood swings.
Moral treatment: Treatment of the mentally ill that involved providing an environment in which people with mental illness were treated with kindness and respect and functioned as part of a community.
Motivational enhancement therapy: A form of treatment specifically designed to boost a patient’s motivation to decrease or stop substance use by highlighting discrepancies between stated personal goals related to substance use and current behavior; also referred to as motivational interviewing.
mNaghten test (or rule): The legal test in which a person is considered insane if, because of a “defect of reason, from disease of the mind,” he or she did not know what he or she was doing (at the time of committing the act) and did not know that it was wrong.
N
Narcissistic personality disorder: A personality disorder characterized by an inflated sense of self-importance, an excessive desire to be admired, and a lack of empathy.
Negative punishment: The type of punishment that takes place when a behavior is followed by the removal of a pleasant or desired event or circumstance, which decreases the probability of that behavior’s recurrence.
Negative reinforcement: The type of reinforcement that occurs when an aversive or uncomfortable stimulus is removed after a behavior, which makes that behavior more likely to be produced again in the future.
Negative symptoms: Symptoms of schizophrenia that are characterized by the absence or reduction of normal mental processes, mental contents, or behaviors.
Neurocognitive disorders: A category of psychological disorders in which the primary symptom is significantly reduced cognitive abilities, relative to a prior level of functioning; also referred to as cognitive disorders.
Neurofibrillary tangles: The mass created by tau proteins that become twisted together and destroy microtubules, leaving the neuron without a distribution system for nutrients.
Neurons: Brain cells that process information related to physical, mental, and emotional functioning.
Neuropsychological testing: The employment of assessment techniques that use behavioral responses to test items in order to draw inferences about brain functioning.
Neuropsychosocial approach: The view that a psychological disorder arises from the combined influences of neurological, psychological, and social factors—which affect and are affected by one another through feedback loops.
Neurosis: According to psychoanalytic theory, a pattern of thoughts, feelings, or behaviors that expresses an unresolved conflict between the ego and the id or between the ego and the superego.
Neurotransmitters: Chemicals that are released by the terminal buttons and cross the synaptic cleft.
O
Objectification theory: The theory that girls learn to consider their bodies as objects and commodities.
Observational learning: The process of learning through watching what happens to others; also referred to as modeling.
Obsessions: Intrusive and unwanted thoughts, urges, or images that persist or recur and usually cause distress or anxiety.
Obsessive-compulsive disorder (OCD): A disorder characterized by one or more obsessions or compulsions.
Obsessive-compulsive personality disorder: A personality disorder characterized by preoccupations with perfectionism, orderliness, and self-control, as well as low levels of flexibility and efficiency.
Operant conditioning: A type of learning in which the likelihood that a behavior will be repeated depends on the consequences associated with the behavior.
Oppositional defiant disorder: A disorder that typically arises in childhood or adolescence and is characterized angry or irritable mood, defiance or argumentative behavior, or vindictiveness.
P
Panic: An extreme sense (or fear) of imminent doom, together with an extreme stress response.
Panic attack: A specific period of intense fear or discomfort, accompanied by physical symptoms, such as a pounding heart, shortness of breath, shakiness, and sweating, or cognitive symptoms, such as a fear of losing control.
Panic disorder: An anxiety disorder characterized by frequent, unexpected panic attacks, along with fear of further attacks and possible restrictions of behavior in order to prevent such attacks.
Paranoid personality disorder: A personality disorder characterized by persistent and pervasive mistrust and suspiciousness, accompanied by a bias to interpret other people’s motives as hostile.
Paraphilia: An intense and persistent sexual interest that is different than the usual fondling or genital stimulation with “normal physically mature consenting human partners.”
Paraphilic disorder: A category of disorders characterized by paraphilias that lead to distress, impaired functioning, or harm—or risk of harm—to the person or to others.
Partial cases: Cases in which patients have symptoms that meet only some of the necessary criteria but not enough symptoms to meet all the necessary criteria for the diagnosis of a disorder.
Pedophilic disorder: A paraphilic disorder in which recurrent sexually arousing fantasies, sexual urges, or behaviors involve a child who has not yet gone through puberty.
Persistent depressive disorder (dysthymia): A depressive disorder that involves as few as two symptoms of a major depressive episode but in which the symptoms persist for at least 2 years.
Personality: Enduring characteristics that lead a person to behave in relatively predictable ways across a range of situations.
Personality disorders: A category of psychological disorders characterized by an enduring pattern of inflexible and maladaptive thoughts, emotional responses, interpersonal functioning, and impulse control problems that arise across a range of situations and lead to distress or dysfunction.
Phenotype: The sum of an organism’s observable traits.
Phobia: An exaggerated fear of an object or a situation, together with an extreme avoidance of the object or situation.
Phototherapy: Treatment for depression that uses full-spectrum lights; also called light-box therapy.
Placebo effect: A positive effect of a medically inert substance or procedure.
Polysubstance abuse: A behavior pattern of abusing more than one substance.
Population: The complete set of possible relevant participants.
Positive punishment: The type of punishment that takes place when a behavior is followed by an undesirable consequence, which makes the behavior less likely to recur.
Positive reinforcement: The type of reinforcement that occurs when a desired reinforcer is received after a behavior, which makes the behavior more likely to occur again in the future.
Positive symptoms: Symptoms of schizophrenia that are characterized by the presence of abnormal or distorted mental processes, mental contents, or behaviors.
Positron emission tomography (PET): A neuroimaging technique that measures blood flow (or energy consumption) in the brain and requires introducing a very small amount of a radioactive substance into the bloodstream.
Posttraumatic stress disorder (PTSD): A traumatic stress disorder that involves persistent (a) intrusive re-experiencing of the traumatic event, (b) avoidance of stimuli related to the event, (c) negative changes in thoughts and mood, and (d) hyperarousal and reactivity that persist for at least a month.
Predictions: Hypotheses that should be confirmed if a theory is correct.
Premature (early) ejaculation: A sexual dysfunction characterized by ejaculation that occurs within a minute of vaginal penetration and before the man wishes it, usually before, immediately during, or shortly after penetration.
Premorbid: Referring to the period of time prior to a patient’s illness.
Prevalence: The number of people who have a disorder in a given period of time.
Privileged communication: Confidential information that is protected from being disclosed during legal proceedings.
Prodromal phase: The phase that is between the onset of symptoms and the time when the minimum criteria for a disorder are met.
Prodrome: Early symptoms of a disorder.
Prognosis: The likely course and outcome of a disorder.
Projective test: A tool for personality assessment in which the patient is presented with ambiguous stimuli (such as inkblots or stick figures) and is asked to make sense of and explain them.
Psychiatric nurse: A mental health professional who has an M.S.N. degree, plus a C.S. certificate in psychiatric nursing.
Psychiatrist: A mental health professional who has an M.D. degree and has completed a residency that focuses on mental disorders.
Psychoactive substance: A chemical that alters mental ability, mood, or behavior.
Psychoanalytic theory: The theory that thoughts, feelings, and behaviors are a result of conscious and unconscious forces continually interacting in the mind.
Psychoeducation: The process of educating patients about research findings and therapy procedures relevant to their situation.
Psychological disorder: A pattern of thoughts, feelings, or behaviors that causes significant personal distress, significant impairment in daily life, and/or significant risk of harm, any of which is unusual for the context and culture in which it arises.
Psychomotor agitation: An inability to sit still, evidenced by pacing, hand wringing, or rubbing or pulling the skin, clothes or other objects.
Psychomotor retardation: A slowing of motor functions indicated by slowed bodily movements and speech and lower volume, variety, or amount of speech.
Psychopathy: A set of emotional and interpersonal characteristics marked by a lack of empathy, an unmerited feeling of high self-worth, and a refusal to accept responsibility for one’s actions.
Psychosexual stages: According to Freud, the sequence of five distinct stages of development (oral, anal, phallic, latency, and genital) through which children proceed from infancy to adulthood; each stage has a key task that must be completed successfully for healthy psychological development.
Psychosis: An impaired ability to perceive reality to the extent that normal functioning is difficult or not possible. The two types of psychotic symptoms are hallucinations and delusions.
Punishment: The process by which an event or object that is the consequence of a behavior decreases the likelihood that the behavior will occur again.
Purging: Attempting to reduce calories that have already been consumed by vomiting or using diuretics, laxatives, or enemas.
R
Random assignment: Assigning participants to each group in a study using a procedure that relies on chance.
Randomized clinical trial (RCT): A research design that has at least two groups—a treatment group and a control group (usually a placebo control)—to which participants are randomly assigned.
Rapid cycling (of moods): Having four or more episodes that meet the criteria for any type of mood episode within 1 year.
Reactivity: A behavior change that occurs when one becomes aware of being observed.
Receptors: Specialized sites on dendrites and cell bodies that respond only to specific molecules.
Reinforcement: The process by which the consequence of a behavior increases the likelihood of the behavior’s recurrence.
Reliable: A property of classification systems (or measures) that consistently produce the same results.
Relief craving: The desire for the temporary emotional relief that can arise from using a substance.
Replication: The process of repeating a study using the same data collection methods under identical or nearly identical conditions to obtain data that should have the same characteristics as those from the original study.
Response bias: The tendency to respond in a particular way, regardless of what is being asked by the question.
Restrained eating: Restricting intake of specific foods or overall number of calories.
Reuptake: The process of moving leftover neurotransmitter molecules in the synapse back into the sending neuron.
Reward craving: The desire for the gratifying effects of using a substance.
S
Sample: The small portion of a population that is examined in a study.
Sampling bias: The distortion that occurs when the participants in an experiment have not been drawn randomly from the relevant population under investigation.
Schizoaffective disorder: A psychotic disorder characterized by the presence of both schizophrenia and a depressive or manic episode.
Schizoid personality disorder: A personality disorder characterized by a restricted range of emotions in social interactions and few—if any—close relationships.
Schizophrenia: A psychological disorder characterized by psychotic symptoms that significantly affect emotions, behavior, and mental processes and mental contents.
Schizophreniform disorder: A psychotic disorder characterized by symptoms that meet all the criteria for schizophrenia except that the symptoms have been present for only 1–6 months, and daily functioning may or may not have declined over that period of time.
Schizotypal personality disorder: A personality disorder characterized by eccentric thoughts, perceptions, and behaviors, in addition to having very few close relationships.
Scientific method: The process of gathering and interpreting facts that generally consists of collecting initial observations, identifying a question, developing a hypothesis that might answer the question, collecting relevant data, developing a theory, and testing the theory.
Selective serotonin reuptake inhibitors (SSRIs): Medications that slow the reuptake of serotonin from synapses.
Sensate focus exercises: A behavioral technique that is assigned as homework in sex therapy, in which a person or couple seeks to increase awareness of pleasurable sensations that do not involve genital touching, intercourse, or orgasm.
Separation anxiety disorder: A disorder that typically arises in childhood and is characterized by excessive anxiety about separation from home or from someone to whom the person is strongly attached.
Sex reassignment surgery: A procedure in which a person’s genitals (and breasts) are surgically altered to appear like those of the other sex.
Sexual dysfunctions: Sexual disorders that are characterized by problems in the sexual response cycle.
Sexual masochism disorder: A paraphilic disorder in which the person repeatedly becomes sexually aroused by fantasies, urges, or behaviors related to being hurt—specifically, being humiliated or made to suffer in other ways—and this arousal pattern causes significant distress or impairs functioning.
Sexual response cycle: The four stages of sexual response—excitement, plateau, orgasm, and resolution—outlined by Masters and Johnson.
Sexual sadism disorder: A paraphilic disorder in which recurrent sexually arousing fantasies, urges, and behaviors inflict, or would inflict, physical or psychological suffering on a nonconsenting person.
Single-participant experiments: Experiments with only a single participant.
Social anxiety disorder: An anxiety disorder characterized by intense fear of public humiliation or embarrassment; also called social phobia.
Social causation hypothesis: The hypothesis that the daily stressors of urban life, especially as experienced by people in a lower socioeconomic class, trigger mental illness in those who are vulnerable.
Social desirability: A bias toward answering questions in a way that respondents think makes them appear socially desirable, even if the responses are not true.
Social selection hypothesis: The hypothesis that people who are mentally ill “drift” to a lower socioeconomic level because of their impairments; also referred to as social drift.
Social support: The comfort and assistance that an individual receives through interactions with others.
Social worker: A mental health professional who has an M.S.W. degree and may have had training to provide psychotherapy to help individuals and families.
Somatic symptom disorder (SSD): A somatic symptom disorder characterized by at least one somatic symptom that is distressing or disrupts daily life, about which the person has excessive thoughts, feelings, or behaviors.
Somatic symptom disorders: A category of psychological disorders characterized by symptoms about physical well-being along with cognitive distortions about bodily symptoms and their meaning; the focus on these bodily symptoms causes significant distress or impaired functioning.
Specific factors: The characteristics of a particular treatment or technique that lead it to have unique benefits, above and beyond those conferred by common factors.
Specific learning disorder: A neurodevelopmental disorder characterized by skills well below average in reading, writing, or math, based on the expected level of performance for the person’s age, general intelligence, cultural group, gender, and education level.
Specific phobia: An anxiety disorder characterized by excessive or unreasonable anxiety about or fear related to a specific situation or object.
Stages of change: A series of five stages that characterizes how ready a person is to change problematic behaviors: precontemplation, contemplation, preparation, action, and maintenance.
Statistically significant: The condition in which the value of a statistical test is greater than what would be expected by chance alone.
Stereotyped behaviors: Repetitive behaviors—such as body rocking—that do not serve a function; also referred to as stereotypies.
Stimulus generalization: The process whereby responses come to be elicited by stimuli that are similar to the conditioned stimulus.
Stroke: The interruption of normal blood flow to or within the brain, which results in neuronal death.
Substance intoxication: The reversible dysfunctional effects on thoughts, feelings, and behavior that arise from the use of a psychoactive substance.
Substance use disorders: Psychological disorders that are characterized by loss of control over urges to use a psychoactive substance, even though such use may impair functioning or cause distress.
Subthreshold cases: Cases in which patients have symptoms that fit all the necessary criteria, but at levels lower than required for the diagnosis of a disorder.
Suicidal ideation: Thoughts of suicide.
Superego: According to Freud, the seat of the conscience, which works to impose morality.
Synapse: The place where the tip of the axon of one neuron sends signals to another neuron.
T
Tarasoff rule: A ruling by the Supreme Court of California (and later other courts) that psychologists have a duty to protect potential victims who are in imminent danger.
Tardive dyskinesia: An enduring side effect of traditional antipsychotic medications that produces involuntary lip smacking and odd facial contortions as well as other movement-related symptoms.
Temperament: The aspects of personality that reflect a person’s typical emotional state and emotional reactivity (including the speed and strength of reactions to stimuli).
Teratogens: Substances or other stimuli that are harmful to a fetus.
Theory: A principle or set of principles that explains a set of data.
Theory of mind: A theory about other people’s mental states (their beliefs, desires, and feelings) that allows a person to predict how other people will react in a given situation.
Tolerance: The biological response that arises from repeated use of a substance such that more of it is required to obtain the same effect.
Transcranial magnetic stimulation (TMS): A procedure that sends sequences of short, strong magnetic pulses into the brain via a coil placed on the scalp, which is used to reduce or eliminate the symptoms of certain psychological disorders.
Transvestic disorder: A paraphilic disorder in which the person cross-dresses for sexual arousal and experiences distress or impaired functioning because of the cross-dressing.
Tricyclic antidepressants (TCAs): Older antidepressants named after the three rings of atoms in their molecular structure.
U
Unconditioned response (UCR): A behavior that is reflexively elicited by a stimulus.
Unconditioned stimulus (UCS): A stimulus that reflexively elicits a behavior.
V
Valid: A property of classification systems (or measures) that actually characterize what they are supposed to characterize.
Vascular dementia: A type of dementia caused by reduced or blocked blood supply to the brain, which arises from plaque buildup or blood clots.
Voyeuristic disorder: A paraphilic disorder in which sexual fantasies, urges, or behaviors involve observing someone who is in the process of undressing, is nude, or is engaged in sexual activity, when the person being observed has neither consented to nor is aware of being observed.
W
Wernickes aphasia: A neurological condition characterized by problems comprehending language and producing meaningful utterances.
Withdrawal: The set of symptoms that arises when a regular substance user decreases or stops intake of an abused substance.