How LSD works in the brain

by Natalie Wolchover

The main theory of psychedelics, first fleshed out by a Swiss researcher named Franz Vollenweider, is that drugs like LSD and psilocybin, the active ingredient in “magic” mushrooms, tune down the thalamus’ activity. Essentially, the thalamus on a psychedelic drug lets unprocessed information through to consciousness, like a bad email spam filter. “Colors become brighter , people see things they never noticed before and make associations that they never made before,” Sewell said.

LSD, or acid, and its mind-bending effects have been made famous by pop culture hits like “Fear and Loathing in Las Vegas,” a film about the psychedelic escapades of writer Hunter S. Thompson. Oversaturated colors, swirling walls and intense emotions all supposedly come into play when you’re tripping. But how does acid make people trip?

Life’s Little Mysteries asked Andrew Sewell, a Yale psychiatrist and one of the few U.S.-based psychedelic drug researchers, to explain why LSD short for lysergic acid diethylamide does what it does to the brain.

His explanation begins with a brief rundown of how the brain processes information under normal circumstances. It all starts in the thalamus, a node perched on top of the brain stem, right smack dab in the middle of the brain. “Most sensory impressions are routed through the thalamus, which acts as a gatekeeper, determining what’s relevant and what isn’t and deciding where the signals should go,” Sewell said.

“Consequently, your perception of the world is governed by a combination of ‘bottom-up’ processing, starting … with incoming signals, combined with ‘top-down’ processing, in which selective filters are applied by your brain to cut down the overwhelming amount of information to a more manageable and relevant subset that you can then make decisions about.

“In other words, people tend to see what they’ve been trained to see, and hear what they’ve been trained to hear.”

The main theory of psychedelics, first fleshed out by a Swiss researcher named Franz Vollenweider, is that drugs like LSD and psilocybin, the active ingredient in “magic” mushrooms, tune down the thalamus’ activity. Essentially, the thalamus on a psychedelic drug lets unprocessed information through to consciousness, like a bad email spam filter. “Colors become brighter , people see things they never noticed before and make associations that they never made before,” Sewell said.

n a recent paper advocating the revival of psychedelic drug research, psychiatrist Ben Sessa of the University of Bristol in England explained the benefits that psychedelics lend to creativity. “A particular feature of the experience is … a general increase in complexity and openness, such that the usual ego-bound restraints that allow humans to accept given pre-conceived ideas about themselves and the world around them are necessarily challenged. Another important feature is the tendency for users to assign unique and novel meanings to their experience together with an appreciation that they are part of a bigger, universal cosmic oneness.”

But according to Sewell, these unique feelings and experiences come at a price: “disorganization, and an increased likelihood of being overwhelmed.” At least until the drugs wear off, and then you’re left just trying to make sense of it all.

http://www.livescience.com/33167-how-acid-lsd-make-people-trip.html?li_source=pm&li_medium=most-popular&li_campaign=related_test

New study shows that use of psychedelic drugs does not increase risk of mental illness

An analysis of data provided by 135,000 randomly selected participants – including 19,000 people who had used drugs such as LSD and magic mushrooms – finds that use of psychedelics does not increase risk of developing mental health problems. The results are published in the Journal of Psychopharmacology.

Previously, the researchers behind the study – from the Norwegian University of Science and Technology in Trondheim – had conducted a population study investigating associations between mental health and psychedelic use. However, that study, which looked at data from 2001-04, was unable to find a link between use of these drugs and mental health problems.

“Over 30 million US adults have tried psychedelics and there just is not much evidence of health problems,” says author and clinical psychologist Pål-Ørjan Johansen.

“Drug experts consistently rank LSD and psilocybin mushrooms as much less harmful to the individual user and to society compared to alcohol and other controlled substances,” concurs co-author and neuroscientist Teri Krebs.

For their study, they analyzed a data set from the US National Health Survey (2008-2011) consisting of 135,095 randomly selected adults from the US, including 19,299 users of psychedelic drugs.

Krebs and Johansen report that they found no evidence for a link between use of psychedelic drugs and psychological distress, depression, anxiety or suicidal thoughts, plans and attempts.

In fact, on a number of factors, the study found a correlation between use of psychedelic drugs and decreased risk for mental health problems.

“Many people report deeply meaningful experiences and lasting beneficial effects from using psychedelics,” says Krebs.

However, Johansen acknowledges that – given the design of the study – the researchers cannot “exclude the possibility that use of psychedelics might have a negative effect on mental health for some individuals or groups, perhaps counterbalanced at a population level by a positive effect on mental health in others.”

Despite this, Johansen believes that the findings of the study are robust enough to draw the conclusion that prohibition of psychedelic drugs cannot be justified as a public health measure.

Krebs says:

“Concerns have been raised that the ban on use of psychedelics is a violation of the human rights to belief and spiritual practice, full development of the personality, and free-time and play.”

Commenting on the research in a piece for the journal Nature, Charles Grob, a paediatric psychiatrist at the University of California-Los Angeles, says the study “assures us that there were not widespread ‘acid casualties’ in the 1960s.” However, he urges caution when interpreting the results, as individual cases of adverse effects can and do occur as a consequence of psychedelic use.

For instance, Grob describes hallucinogen persisting perception disorder, sometimes referred to as “a never-ending trip.” Patients with this disorder experience “incessant distortions” in their vision, such as shimmering lights and colored dots. “I’ve seen a number of people with these symptoms following a psychedelic experience, and it can be a very serious condition,” says Grob.

http://www.medicalnewstoday.com/articles/290461.php

Brief History of 8 Hallucinogens

Humans have been ingesting mind-altering substances for a very long time. Hallucinogen-huffing bowls 2,500 years old (http://www.livescience.com/5240-ancient-family-heirlooms-snort-hallucinogens.html) have been found on islands in the Lesser Antilles, and traditional cultures from the Americas to Africa use hallucinogenic substances for spiritual purposes. Here are some notable substances that send the mind tripping.

LSD is commonly known as “acid,” but its scientific name is a mouthful: lysergic acid diethylamaide. The drug was first synthesized in 1938 from a chemical called ergotamine. Ergotamine, in turn, is produced by a grain fungus that grow on rye.

LSD was originally produced by a pharmaceutical company under the name Delysid, but it got a bad reputation in the 1950s when the CIA decided to research its effects on mind control. The test subjects of the CIA project MKULTRA proved very difficult to control indeed, and many, like counter-culture writer Ken Kesey, started taking the drug for fun (and for their own form of 1960s enlightenment).

ayahuasca-vine-110929

Ayahuasca is a hallucinatory mixture of Amazonian infusions centered around the Banisteriopsis caapi vine. The brew has long been used by native South American tribes for spiritual rituals and healing, and like other hallucinogens, ayahuasca often triggers very intense emotional experiences (vomiting is also common). In 2006, National Geographic writer Kira Salak described her experience with ayahuasca in Peru for the magazine.

” I will never forget what it was like. The overwhelming misery. The certainty of never-ending suffering. No one to help you, no way to escape. Everywhere I looked: darkness so thick that the idea of light seemed inconceivable,” Salak wrote. “Suddenly, I swirled down a tunnel of fire, wailing figures calling out to me in agony, begging me to save them. Others tried to terrorize me. ‘You will never leave here,’ they said. ‘Never. Never.'”

Nonetheless, Salak wrote, when she broke free of her hallucinations, her crippling depression was alleviated. It’s anecdotal experiences like this that have led researchers to investigate the uses of hallucinogens as therapy for mental disorders such as anxiety, depression and post-traumatic stress disorder.

Peyote is a cactus that gets its hallucinatory power from mescaline. Like most hallucinogens, mescaline binds to serotonin receptors in the brain, producing heightened sensations and kaleidoscopic visions.

Native groups in Mexico have used peyote in ceremonies for thousands of years, and other mescaline-producing cacti have long been used by South American tribes for their rituals. Peyote has been the subject of many a court battle because of its role in religious practice; currently, Arizona, Colorado, New Mexico, Nevada and Oregon allow some peyote possession, but only if linked to religious ceremonies, according to Arizona’s Peyote Way Church of God.

The “magic” ingredient in hallucinogenic mushrooms is psilocybin, a compound that breaks down into psilocin in the body. Psilocin bonds to serotonin receptors all over the brain, and can cause hallucinations as well as synesthesia, or the mixture of two senses. Under the influence, for example, a person might feel that they can smell colors.

In keeping with the human tradition of eating anything that might alter your mind, people have been ingesting psilocybin-continuing mushrooms for thousands of years. Synthetic psilocybin is now under study as a potential treatment for anxiety, depression and addiction.

Best known by its street name, “angel dust,” PCP stands for phencyclidine. The drug blocks receptors in the brain for the neurotransmitter glutamate. It’s more dangerous than other hallucinogens, with schizophrenia-like symptoms and nasty side effects.

Those side effects are why PCP has no medical uses. The drug was tested as an anesthetic in the 1950s and used briefly to knock out animals during veterinary surgeries. But by the 1960s, PCP had hit the streets and was being used as a recreation drug, famous for the feelings of euphoria and invincibility it bestowed on the user. Unfortunately, a side effect of all that euphoria is sometimes truly destructive behavior, including users trying to jump out of windows or otherwise self-mutilating. Not to mention that high enough doses can cause convulsions.

Derived from the African iboga plant, ibogaine is another hallucinogen with a long history of tribal use. More recently, the drug has shown promise in treating addiction, although mostly in Mexico and Europe where ibogaine treatment is not prohibited as it is in the U.S.

Using ibogaine as therapy is tricky, however. The drug can cause heart rhythm problems, and vomiting is a common side effect. The Massachusetts-based Multidisciplinary Association for Psychedelic Research (MAPS) reports that an estimated 1 in 300 ibogaine users die due to the drug. The group is studying the long-term effects of ibogaine on patients in drug treatment programs in New Zealand and Mexico.

Salvia divinorum, also known as seer’s or diviner’s sage, grows in the cloud forest of Oaxaca, Mexico. The native Mazatec people have long used tea made out of the leaves in spiritual ceremonies, but the plant can also be smoked or chewed for its hallucinogenic effects.

Salvia is not currently a controlled substance, according to the National Institute on Drug Abuse, but it is under consideration to be made illegal and placed in the same drug class as marijuana.

Ecstasy, “E” or “X” are the street names for MDMA, or (get ready for a long one) 3,4-methylenedioxymethamphetamine. The drug acts on serotonin in the brain, causing feelings of euphoria, energy and distortions of perception. It can also nudge body temperatures up, raising the risk of heat stroke. Animal studies suggest that MDMA causes long-term and potentially dangerous changes in the brain, according to the National Institute on Drug Abuse.

MDMA was first synthesized by a chemist looking for substances to stop bleeding in 1912. No one paid the compound much mind for the next half-decade, but by the 1970s, MDMA had hit the streets. It was popular at raves and nightclubs and among those who liked their music psychedelic. Today, ecstasy is still a common street drug, but researchers are investigating whether MDMA could be used to treat post-traumatic stress disorder and cancer-related anxiety.

http://www.livescience.com/16286-hallucinogens-lsd-mushrooms-ecstasy-history.html