Euphoria

History of the term

The word "euphoria" is derived from the Ancient Greek terms εὐφορία: εὖ eu meaning "well" and φέρω pherō meaning "to bear". It is semantically opposite to dysphoria.

A 1706 English dictionary defined euphoria as "the well bearing of the Operation of a Medicine, i.e., when the patient finds himself eas'd or reliev'd by it".

In the 1860s, the English physician Thomas Laycock described euphoria as the feeling of bodily well-being and hopefulness; he noted its misplaced presentation in the final stage of some terminal illnesses and attributed such euphoria to neurological dysfunction. Sigmund Freud's 1884 monograph Über Coca described (his own) consumption of cocaine producing "the normal euphoria of a healthy person", while about 1890 the German neuropsychiatrist Carl Wernicke lectured about the "abnormal euphoria" in patients with mania.

A 1903 article in The Boston Daily Globe refers to euphoria as "pleasant excitement" and "the sense of ease and well-being,". In 1920 Popular Science magazine described euphoria as "a high sounding name" meaning "feeling fit": normally making life worth living, motivating drug use, and ill formed in certain mental illnesses. In 1940 The Journal of Psychology defined euphoria as a "state of general well being ... and pleasantly toned feeling." A decade later, finding ordinary feelings of well being difficult to evaluate, American addiction researcher Harris Isbell redefined euphoria as behavioral changes and objective signs typical of morphine. However, in 1957 British pharmacologist D. A. Cahal did not regard opioid euphoria as medically undesirable but an affect which "enhance[s] the value of a major analgesic." The 1977 edition of A Concise Encyclopaedia of Psychiatry called euphoria "a mood of contentment and well-being," with pathologic associations when used in a psychiatric context. As a sign of cerebral disease, it was described as bland and out of context, representing an inability to experience negative emotion.

In the 21st century, euphoria is generally defined as a state of great happiness, well-being and excitement, which may be normal, or abnormal and inappropriate when associated with psychoactive drugs, manic states, or brain disease or injury.

Types

Many different types of stimuli can induce euphoria, including psychoactive drugs, natural rewards, and social activities. Affective disorders such as unipolar mania or bipolar disorder can involve euphoria as a symptom.

Exercise-induced

Continuous physical exercise, particularly aerobic exercise, can induce a state of euphoria; for example, distance running is often associated with a "runner's high", which is a pronounced state of exercise-induced euphoria. Exercise is known to affect dopamine signaling in the nucleus accumbens, producing euphoria as a result, through increased biosynthesis of three particular neurochemicals: anandamide (an endocannabinoid), β-endorphin (an endogenous opioid), and phenethylamine (a trace amine and amphetamine analog).

Music euphoria

Euphoria can occur as a result of dancing to music, music-making, and listening to emotionally arousing music. Neuroimaging studies have demonstrated that the reward system plays a central role in mediating music-induced pleasure. Pleasurable emotionally arousing music strongly increases dopamine neurotransmission in the dopaminergic pathways that project to the striatum (i.e., the mesolimbic pathway and nigrostriatal pathway). Approximately 5% of the population experiences a phenomenon termed "musical anhedonia", in which individuals do not experience pleasure from listening to emotionally arousing music despite having the ability to perceive the intended emotion that is conveyed in passages of music.

Drug-induced

A euphoriant is a type of psychoactive drug which tends to induce euphoria. Most euphoriants are addictive drugs due to their reinforcing properties and ability to activate the brain's reward system.

Stimulants

Dopaminergic stimulants like amphetamine, methamphetamine, cocaine, MDMA, and methylphenidate are euphoriants. Nicotine is a parasympathetic stimulant that acts as a mild euphoriant in some people.

Depressants

Certain depressants can produce euphoria; some of the euphoriant drugs in this class include drinking alcohol (i.e., ethanol) in moderate doses, γ-hydroxybutyric acid, and ketamine. Euphoria has also been noted to occur in a very small percentage of individuals who used pregabalin in controlled trials as a treatment for neuropathic pain associated with diabetic peripheral neuropathy.

Some barbiturates and benzodiazepines may cause euphoria. Euphoriant effects are determined by the drug's speed of onset, increasing dose, and with intravenous administration. Barbiturates more likely to cause euphoria include amobarbital, secobarbital and pentobarbital. Benzodiazepines more likely to cause euphoria are flunitrazepam, alprazolam and clonazepam. Benzodiazepines also tend to enhance opioid-induced euphoria.

Opioids

µ-Opioid receptor agonists are a set of euphoriants that include drugs such as heroin, morphine, codeine, oxycodone, and fentanyl. By contrast, κ-opioid receptor agonists, like the endogenous neuropeptide dynorphin, are known to cause dysphoria, a mood state opposite to euphoria that involves feelings of profound discontent.

Cannabinoids

Cannabinoid receptor 1 agonists are a group of euphoriants that includes certain plant-based cannabinoids (e.g., THC from the cannabis plant), endogenous cannabinoids (e.g., anandamide), and synthetic cannabinoids.

Inhalants

Certain gases, like nitrous oxide (N₂O, aka "laughing gas"), can induce euphoria when inhaled.

Glucocorticoids

Acute exogenous glucocorticoid administration is known to produce euphoria, but this effect is not observed with long-term exposure.

Asphyxia-induced

Asphyxiation initially produces an extreme feeling of euphoria leading some people to intentionally induce temporary asphyxiation. Erotic asphyxiation typically employs strangulation to produce euphoria which enhances masturbation and orgasm. The choking game, prevalent in adolescents, uses brief hypoxia in the brain to achieve euphoria. Strangulation, or hyperventilation followed by breath holding are commonly used to achieve the effects. Accidental deaths occur from both practices but are often mislabeled as suicide.

Mania

Euphoria is also strongly associated with both hypomania and mania, mental states characterized by a pathological heightening of mood, which may be either euphoric or irritable, in addition to other symptoms, such as pressured speech, flight of ideas, and grandiosity.

Although hypomania and mania are syndromes with multiple etiologies (that is, ones that may arise from any number of conditions), they are most commonly seen in bipolar disorder, a psychiatric illness characterized by alternating periods of mania and depression.

Epilepsy

Brief euphoria may occur immediately before or during epileptic seizures originating in the temporal lobes or insulae. This euphoria is symptomatic of a rare syndrome called ecstatic seizures, itself closely associated with religious and mystical experiences which are often euphoric. Euphoria (or more commonly dysphoria) may also occur in periods between such seizures. This condition, interictal dysphoric disorder, is considered an atypical affective disorder.

Multiple sclerosis

Euphoria sometimes occurs in persons with multiple sclerosis as the illness progresses. This euphoria is part of a syndrome originally called euphoria sclerotica, which typically includes disinhibition and other symptoms of cognitive and behavioral dysfunction.