Reference Terms
from Wikipedia, the free encyclopedia
Opioid drug
An opioid is any agent that binds to opioid receptors, found principally in the central nervous system and gastrointestinal tract. There are four broad classes of opioids: endogenous opioid peptides, produced in the body; opium alkaloids, such as morphine (the prototypical opioid) and codeine; semi-synthetic opioids such as heroin and oxycodone; and fully synthetic opioids such as pethidine and methadone that have structures unrelated to the opium alkaloids. Opioids have long been used to treat acute pain (such as post-operative pain). They have also found to be invaluable in palliative care to alleviate the severe, chronic, disabling pain of terminal conditions such as cancer. Very high doses are often required in palliation to improve the patients' terminal quality-of-life.
Related Stories
1
2
Mind & Brain News
October 16, 2025
Oct. 16, 2025 — Long before humans built cities or wrote words, our ancestors may have faced a hidden threat that shaped who we became. Scientists studying ancient teeth found that early humans, great apes, and even Neanderthals were exposed to lead millions of ...
Oct. 16, 2025 — Johns Hopkins scientists uncovered microscopic “nanotube” channels that neurons use to transfer toxic molecules. While this process clears waste, it can also spread harmful proteins like amyloid-beta. Alzheimer’s-model mice showed more ...
Oct. 14, 2025 — Researchers have synthesized enhanced vitamin K analogues that outperform natural vitamin K in promoting neuron growth. The new compounds, which combine vitamin K with retinoic acid, activate the mGluR1 receptor to drive neurogenesis. They also ...
Oct. 14, 2025 — Researchers at USC have created the first method to noninvasively measure microscopic blood vessel pulses in the human brain. Using advanced 7T MRI, they found these tiny pulsations grow stronger with age and vascular risk, disrupting the brain’s ...
Oct. 14, 2025 — Groundbreaking Harvard research is exposing hidden energy failures inside brain cells that may drive major psychiatric conditions. By studying reprogrammed neurons, scientists are revealing how cellular metabolism shapes mood, thought, and ...
Oct. 14, 2025 — UMass Amherst engineers have built an artificial neuron powered by bacterial protein nanowires that functions like a real one, but at extremely low voltage. This allows for seamless communication with biological cells and drastically improved energy ...
Oct. 13, 2025 — Finasteride, a common hair-loss drug, has long been tied to depression and suicide, but regulators ignored the warnings. Prof. Mayer Brezis’s review exposes global data showing psychiatric harm and a pattern of inaction by Merck and the FDA. ...
Oct. 13, 2025 — People experiencing their first psychotic episode who also have skin conditions such as rashes or itching are at greater risk of depression and suicidal thoughts, according to new research presented at the ECNP meeting. Scientists found that 25% of ...
Oct. 12, 2025 — Different types of depression affect the body in different ways. Atypical, energy-related depression raises the risk of diabetes, while melancholic depression increases the likelihood of heart disease. Scientists say these differences reflect ...
Oct. 11, 2025 — Researchers have identified two compounds, K102 and K110, that could repair the nerve damage from multiple sclerosis. These drugs help regenerate the protective myelin sheath and balance immune ...
Oct. 11, 2025 — Scientists identified two types of brain cells, neurons and microglia, that are altered in people with depression. Through genomic mapping of post-mortem brain tissue, they found major differences in gene activity affecting mood and inflammation. ...
Oct. 10, 2025 — Scientists have pinpointed Y1 receptor neurons in the brain that can override chronic pain signals when survival instincts like hunger or fear take precedence. Acting like a neural switchboard, these cells balance pain with other biological needs. ...
Latest Headlines
updated 12:56 pm ET
Oct. 13, 2025 — Researchers have discovered that ADHD’s hallmark mind wandering might actually boost creativity. People who deliberately let their thoughts drift scored higher on creative tests in two large ...
Oct. 11, 2025 — Dolphins washing up on Florida’s shores may be victims of the same kind of brain degeneration seen in humans with Alzheimer’s disease. Researchers discovered that cyanobacterial toxins—worsened ...
Oct. 8, 2025 — Scientists at Skoltech developed a new mathematical model of memory that explores how information is encoded and stored. Their analysis suggests that memory works best in a seven-dimensional ...
Oct. 8, 2025 — Researchers have designed a peptide that prevents the deadly misfolding of alpha-synuclein, the protein behind Parkinson’s and some dementias. In ...
Oct. 7, 2025 — Scientists have discovered that DMT, a natural compound found in plants and even the human brain, can dramatically reduce brain damage caused by stroke. The psychoactive molecule, long known for its ...
Oct. 7, 2025 — Researchers in Japan have pinpointed a biological cause of Long COVID brain fog using advanced PET brain imaging. They discovered widespread ...
Oct. 7, 2025 — Addiction often isn’t about chasing pleasure—it’s about escaping pain. Researchers at Scripps Research have discovered that a tiny brain region ...
Oct. 6, 2025 — A University of New Mexico scientist is revealing what might be one of the most overlooked causes of dementia — damage in the brain’s tiny blood vessels. Dr. Elaine Bearer has created a new way ...
Oct. 5, 2025 — A new study shows glioblastoma isn’t confined to the brain—it erodes the skull and hijacks the immune system within skull marrow. The cancer opens channels that let inflammatory cells enter the ...
Oct. 5, 2025 — Stanford scientists found that aging disrupts the brain’s internal navigation system in mice, mirroring spatial memory decline in humans. Older mice struggled to recall familiar locations, while a ...