Cannabis: The plant genus in the Cannabaceae plant family, Urticales order, Hamamelidae subclass. The flowering tops are called many slang terms including pot, marijuana, hashish, bhang, and ganja. The stem is an important source of hemp fiber.Marijuana Abuse: The excessive use of marijuana with associated psychological symptoms and impairment in social or occupational functioning.Marijuana Smoking: Inhaling and exhaling the smoke from CANNABIS.Dronabinol: A psychoactive compound extracted from the resin of Cannabis sativa (marihuana, hashish). The isomer delta-9-tetrahydrocannabinol (THC) is considered the most active form, producing characteristic mood and perceptual changes associated with this compound.Cannabidiol: Compound isolated from Cannabis sativa extract.Cannabinoids: Compounds having the cannabinoid structure. They were originally extracted from Cannabis sativa L. The most pharmacologically active constituents are TETRAHYDROCANNABINOL; CANNABINOL; and CANNABIDIOL.Psychoses, Substance-Induced: Psychotic organic mental disorders resulting from the toxic effect of drugs and chemicals or other harmful substance.Cannabinol: A physiologically inactive constituent of Cannabis sativa L.Street Drugs: Drugs obtained and often manufactured illegally for the subjective effects they are said to produce. They are often distributed in urban areas, but are also available in suburban and rural areas, and tend to be grossly impure and may cause unexpected toxicity.Substance Withdrawal Syndrome: Physiological and psychological symptoms associated with withdrawal from the use of a drug after prolonged administration or habituation. The concept includes withdrawal from smoking or drinking, as well as withdrawal from an administered drug.Substance Abuse Detection: Detection of drugs that have been abused, overused, or misused, including legal and illegal drugs. Urine screening is the usual method of detection.Substance-Related Disorders: Disorders related to substance abuse.Receptor, Cannabinoid, CB1: A subclass of cannabinoid receptor found primarily on central and peripheral NEURONS where it may play a role modulating NEUROTRANSMITTER release.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)Hallucinogens: Drugs capable of inducing illusions, hallucinations, delusions, paranoid ideations, and other alterations of mood and thinking. Despite the name, the feature that distinguishes these agents from other classes of drugs is their capacity to induce states of altered perception, thought, and feeling that are not experienced otherwise.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)Psychotropic Drugs: A loosely defined grouping of drugs that have effects on psychological function. Here the psychotropic agents include the antidepressive agents, hallucinogens, and tranquilizing agents (including the antipsychotics and anti-anxiety agents).Cannabinoid Receptor Agonists: Compounds that interact with and stimulate the activity of CANNABINOID RECEPTORS.Alcohol Drinking: Behaviors associated with the ingesting of alcoholic beverages, including social drinking.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.Student Dropouts: Individuals who leave school, secondary or college, prior to completion of specified curriculum requirements.Cannabinoid Receptor Modulators: Compounds that interact with and modulate the activity of CANNABINOID RECEPTORS.Diseases in Twins: Disorders affecting TWINS, one or both, at any age.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.Diagnosis, Dual (Psychiatry): The co-existence of a substance abuse disorder with a psychiatric disorder. The diagnostic principle is based on the fact that it has been found often that chemically dependent patients also have psychiatric problems of various degrees of severity.Gas Chromatography-Mass Spectrometry: A microanalytical technique combining mass spectrometry and gas chromatography for the qualitative as well as quantitative determinations of compounds.Drug Users: People who take drugs for a non-therapeutic or non-medical effect. The drugs may be legal or illegal, but their use often results in adverse medical, legal, or social consequences for the users.Psychiatric Status Rating Scales: Standardized procedures utilizing rating scales or interview schedules carried out by health personnel for evaluating the degree of mental illness.Alcoholism: A primary, chronic disease with genetic, psychosocial, and environmental factors influencing its development and manifestations. The disease is often progressive and fatal. It is characterized by impaired control over drinking, preoccupation with the drug alcohol, use of alcohol despite adverse consequences, and distortions in thinking, most notably denial. Each of these symptoms may be continuous or periodic. (Morse & Flavin for the Joint Commission of the National Council on Alcoholism and Drug Dependence and the American Society of Addiction Medicine to Study the Definition and Criteria for the Diagnosis of Alcoholism: in JAMA 1992;268:1012-4)Prodromal Symptoms: Clinical or physiological indicators that precede the onset of disease.Receptors, Cannabinoid: A class of G-protein-coupled receptors that are specific for CANNABINOIDS such as those derived from CANNABIS. They also bind a structurally distinct class of endogenous factors referred to as ENDOCANNABINOIDS. The receptor class may play a role in modulating the release of signaling molecules such as NEUROTRANSMITTERS and CYTOKINES.Schizophrenia: A severe emotional disorder of psychotic depth characteristically marked by a retreat from reality with delusion formation, HALLUCINATIONS, emotional disharmony, and regressive behavior.Social Environment: The aggregate of social and cultural institutions, forms, patterns, and processes that influence the life of an individual or community.Tobacco Use Disorder: Tobacco used to the detriment of a person's health or social functioning. Tobacco dependence is included.Smoking: Inhaling and exhaling the smoke of burning TOBACCO.Twins, Dizygotic: Two offspring from the same PREGNANCY. They are from two OVA, fertilized at about the same time by two SPERMATOZOA. Such twins are genetically distinct and can be of different sexes.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.Adolescent Behavior: Any observable response or action of an adolescent.Coca: Any of several South American shrubs of the Erythroxylon genus (and family) that yield COCAINE; the leaves are chewed with alum for CNS stimulation.Precipitating Factors: Factors associated with the definitive onset of a disease, illness, accident, behavioral response, or course of action. Usually one factor is more important or more obviously recognizable than others, if several are involved, and one may often be regarded as "necessary". Examples include exposure to specific disease; amount or level of an infectious organism, drug, or noxious agent, etc.Phencyclidine Abuse: The misuse of phencyclidine with associated psychological symptoms and impairment in social or occupational functioning.Behavior, Addictive: The observable, measurable, and often pathological activity of an organism that portrays its inability to overcome a habit resulting in an insatiable craving for a substance or for performing certain acts. The addictive behavior includes the emotional and physical overdependence on the object of habit in increasing amount or frequency.Comorbidity: The presence of co-existing or additional diseases with reference to an initial diagnosis or with reference to the index condition that is the subject of study. Comorbidity may affect the ability of affected individuals to function and also their survival; it may be used as a prognostic indicator for length of hospital stay, cost factors, and outcome or survival.