Habeas Corpus - Latin, meaning "you have the body." A writ of habeas corpus generally is a judicial order forcing law enforcement authorities to produce a prisoner they are holding, and to justify the prisoner's continued confinement.

Habilitate - The process of teaching the skills needed for successful living. Habilitation helps people recover from addiction by teaching life skills that were never learned because drug use interfered with the learning and maturation process. Habilitation is especially important for addicts who started drug use young.

Habilitation - Training in life skills such as housekeeping that will allow a developmentally disabled person to live in the least restrictive environment

Halcion - A depressant drug of the benzodiazepine family used to induce sleep.

Halflife - The amount of time it takes for half of the amount of a drug in the body to be removed.

Hallucination - An abnormal sensory experience that arises in the absence of a direct external stimulus, and which has the qualities of a normal percept and is experienced as real and usually in external space. Hallucinations may occur in any sensory modality.

Hallucinogens - A diverse group of drugs that alter perceptions, thoughts and feelings.

Hardness - A mostly meaningless measure of a drug's dangerousness. Drugs like caffeine are considered "soft" while drugs like heroin and cocaine are considered "hard".

Harmless Error - An error committed during a trial that was corrected or was not serious enough to affect the outcome of a trial and therefore was not sufficiently harmful (prejudicial) to be reversed on appeal.

Headnote - A brief summary of a legal rule or significant facts in a case, which along with other headnotes, precedes the printed opinion in reports.

Health - A general condition of soundness and vigor of body and mind; not simply the absence of illness or injury.

Health Promotion - The development and implementation of general strategies and specific tactics to eliminate or reduce the risk that people will become ill.

Health Psychology - The field of psychology devoted to understanding the ways people stay healthy, the reasons they become ill, and the ways they respond when they become ill.

Hearing - A formal proceeding (generally less formal than a trial) with definite issues of law or of fact to be heard. Hearings are used extensively by legislative and administrative agencies.

Hearing De Novo - A full new hearing.

Hearing Officer - Conducts hearings and issues recommendations and administrative orders. (See Administrative Hearing)

Hearsay - Statements by a witness who did not see or hear the incident in question but heard about it from someone else. Hearsay is usually not admissible as evidence in court.

Hedonism - Pleasure-seeking behavior. Contrast with anhedonia.

Heirs - Person entitled by law to inherit the estate of a deceased person

Hepatitis - Inflammation of the liver.

Heredity - The biological transmission of traits from parents to offspring.

Heritability Estimate - A statistical estimate of the degree of inheritance of a given trait or behavior, assessed by the degree of similarity between individuals who vary in their extent of genetic similarity.

Heroin - The potent, widely abused opiate that produces a profound addiction. It consists of two morphine molecules linked together chemically.

Heuristics - Cognitive strategies, or "rules of thumb," often used as shortcuts in solving a complex inferential task.

Hierarchy of Needs - Maslow's view that basic human motives form a hierarchy and that the needs at each level of the hierarchy must be satisfied before the next level can be achieved; these needs progress from basic biological needs to the need for transcendence.

Hippocampus - The part of the limbic system that is involved in the acquisition of explicit memory.

HIV - Human immunodeficiency virus, a virus that attacks white blood cells (T lymphocytes) in human blood, thereby weakening the functioning of the immune system; HIV causes AIDS.

Home Confinement - A special condition the court imposes that requires an individual to remain at home except for certain approved activities such as work and medical appointments. Home confinement may include the use of electronic monitoring equipment – a transmitter attached to the wrist or the ankle – to help ensure that the person stays at home as required.

Home State - The state in which a child lived with a parent or caretaker for at least six consecutive months immediately preceding the time of filing of a complaint or comparable pleading for support. If a child is less than six months old, the state in which the child lived from birth.

Home Study - A prerequisite to foster or adoptive placement that consists of an assessment of the prospective foster or adoptive parent's personal history, financial and employment status, health status, home environment, and criminal history.

Homeostasis - The process of keeping the internal environment of the body stable while the outside world changes.

Horizontal Cells - The cells that integrate information across the retina; rather than sending signals toward the brain, horizontal cells connect receptors to each other.

Hormones - The chemical messengers, manufactured and secreted by the endocrine glands, that regulate metabolism and influence body growth, mood, and sexual characteristics.

Hostile Witness - A witness whose testimony is not favorable to the party who calls him or her as a witness. A hostile witness may be asked leading questions and may be cross-examined by the party who calls him or her to the stand.

Hue - The dimension of color space that captures the qualitative experience of the color of a light.

Human Behavior Genetics - The area of study that evaluates the genetic component of individual differences in behaviors and traits.

Humanistic Perspective - A psychological model that emphasizes an individual's phenomenal world and inherent capacity for making rational choices and developing to maximum potential.

Human-Potential Movement - The therapy movement that encompasses all those practices and methods that release the potential of the average human being for greater levels of performance and greater richness of experience.

Hung Jury - A jury whose members cannot agree upon a verdict.

Hycodan - An antitussive containing hydrocodone mixed with homatropine methylbromide.

Hycomine - An antitussive containing hydrocodone mixed with Phenylpropanolamine.

Hydrocodone - A codeine derivative which is roughly six times as potent. It has the same chemical formula as codeine but a different geometrical structure.

Hydromorphone - Dilaudid.

Hydroxyindoleacetic Acid - A major metabolite of serotonin, a biogenic amine found in the brain and other organs. Functional deficits of serotonin in the central nervous system have been implicated in certain types of major mood disorders, and particularly in suicide and impulsivity.

Hyperacusis - Inordinate sensitivity to sounds; it may be on an emotional or an organic basis.

Hypersomnia - Excessive sleepiness, as evidenced by prolonged nocturnal sleep, difficulty maintaining an alert awake state during the day, or undesired daytime sleep episodes. ideas of reference The feeling that casual incidents and external events have a particular and unusual meaning that is specific to the person. This is to be distinguished from a delusion of reference, in which there is a belief that is held with delusional conviction

Hypnagogic - Referring to the semiconscious state immediately preceding sleep; may include hallucinations that are of no pathological significance.

Hypnopompic  - Referring to the state immediately preceding awakening; may include hallucinations that are of no pathological significance.

Hypnosis - An altered state of awareness characterized by deep relaxation, susceptibility to suggestions, and changes in perception, memory, motivation, and self-control.

Hypnotic - A drug that induces sleep.

Hypnotizability - The degree to which an individual is responsive to standardized hypnotic suggestion.

Hypomania - An affective disorder characterised by elation, overactivity, an insomnia.

Hypothalamus - The part of the brain that controls many bodily functions, including feeding, drinking, and the release of many hormones.

Hypothesis - A tentative and testable explanation of the relationship between two (or more) events or variables; often stated as a prediction that a certain outcome will result from specific conditions.

Hypothetical Question - An imaginary situation, incorporating facts previously admitted into evidence, upon which an expert witness is permitted to give an opinion as to a condition resulting from the situation.