In psychology

Psychology

Psychology is the study of the mind and behavior. Its immediate goal is to understand individuals and groups by both establishing general principles and researching specific cases. For many, the ultimate goal of psychology is to benefit society...

, a rush is an acute transcendent state of euphoria

Euphoria

Euphoria is an emotional and mental state defined as a sense of great elation and well being.Euphoria may also refer to:* Euphoria , a genus of scarab beetles* Euphoria, a genus name previously used for the longan and other trees...

. Psychoactive drug

Psychoactive drug

A psychoactive drug, psychopharmaceutical, or psychotropic is a chemical substance that crosses the blood–brain barrier and acts primarily upon the central nervous system where it affects brain function, resulting in changes in perception, mood, consciousness, cognition, and behavior...

s which enhance dopaminergic

Dopaminergic

Dopaminergic means related to the neurotransmitter dopamine. For example, certain proteins such as the dopamine transporter , vesicular monoamine transporter 2 , and dopamine receptors can be classified as dopaminergic, and neurons which synthesize or contain dopamine and synapses with dopamine...

 neurotransmission

Neurotransmission

Neurotransmission , also called synaptic transmission, is the process by which signaling molecules called neurotransmitters are released by a neuron , and bind to and activate the receptors of another neuron...

 in the central nervous system

Central nervous system

The central nervous system is the part of the nervous system that integrates the information that it receives from, and coordinates the activity of, all parts of the bodies of bilaterian animals—that is, all multicellular animals except sponges and radially symmetric animals such as jellyfish...

 (CNS) are commonly capable of such an event.

These drugs include opiates and opioids, such as heroin and morphine

Morphine

Morphine is a potent opiate analgesic medication and is considered to be the prototypical opioid. It was first isolated in 1804 by Friedrich Sertürner, first distributed by same in 1817, and first commercially sold by Merck in 1827, which at the time was a single small chemists' shop. It was more...

, and psychostimulants, such as methamphetamine

Methamphetamine

Methamphetamine is a psychostimulant of the phenethylamine and amphetamine class of psychoactive drugs...

 and cocaine

Cocaine

Cocaine is a crystalline tropane alkaloid that is obtained from the leaves of the coca plant. The name comes from "coca" in addition to the alkaloid suffix -ine, forming cocaine. It is a stimulant of the central nervous system, an appetite suppressant, and a topical anesthetic...

. Studies have shown that the subjective pleasure of drug use (the reinforcing component of addiction) is proportional to the rate at which the blood level of the drug increases. Smoking is the fastest route of administration, causing blood concentrations to rise the most quickly, followed by intravenous injection, suppository

Suppository

A suppository is a drug delivery system that is inserted into the rectum , vagina or urethra , where it dissolves.They are used to deliver both systemically-acting and locally-acting medications....

 (anal or vaginal insertion), insufflation

Insufflation (medicine)

Insufflation is the practice of inhaling a substance. Insufflation has limited medical use, but is a common route of administration with many respiratory drugs used to treat conditions in the lungs and paranasal sinus .The technique is common for many recreational drugs and is also used for some...

 (snorting), and ingestion

Ingestion

Ingestion is the consumption of a substance by an organism. In animals, it normally is accomplished by taking in the substance through the mouth into the gastrointestinal tract, such as through eating or drinking...

(swallowing). Ingestion does not produce a rush.