How psychedelic drug psilocybin works on brain
June 5, 2020
Science Daily/Johns Hopkins Medicine
To see how psychedelics impact the claustrum, a mysterious region of the brain believed to control the ego, researchers compared the brain scans of people after they took psilocybin with their scans after taking a placebo.
Perhaps no region of the brain is more fittingly named than the claustrum, taken from the Latin word for "hidden or shut away." The claustrum is an extremely thin sheet of neurons deep within the cortex, yet it reaches out to every other region of the brain. Its true purpose remains "hidden away" as well, with researchers speculating about many functions. For example, Francis Crick of DNA-discovery fame believed that the claustrum is the seat of consciousness, responsible for awareness and sense of self.
What is known is that this region contains a large number of receptors targeted by psychedelic drugs such as LSD or psilocybin ¾ the hallucinogenic chemical found in certain mushrooms. To see what happens in the claustrum when people are on psychedelics, Johns Hopkins Medicine researchers compared the brain scans of people after they took psilocybin with their scans after taking a placebo.
Their findings were published online on May 23, 2020, in the journal NeuroImage.
The scans after psilocybin use showed that the claustrum was less active, meaning the area of the brain believed responsible for setting attention and switching tasks is turned down when on the drug. The researchers say that this ties in with what people report as typical effects of psychedelic drugs, including feelings of being connected to everything and reduced senses of self or ego.
"Our findings move us one step closer to understanding mechanisms underlying how psilocybin works in the brain," says Frederick Barrett, Ph.D., assistant professor of psychiatry and behavioral sciences at the Johns Hopkins University School of Medicine and a member of the school's Center for Psychedelic and Consciousness Research. "This will hopefully enable us to better understand why it's an effective therapy for certain psychiatric disorders, which might help us tailor therapies to help people more."
Because of its deep-rooted location in the brain, the claustrum has been difficult to access and study. Last year, Barrett and his colleagues at the University of Maryland, Baltimore, developed a method to detect brain activity in the claustrum using functional magnetic resonance imaging (fMRI).
For this new study, the researchers used fMRI with 15 people and observed the claustrum brain region after the participants took either psilocybin or a placebo. They found that psilocybin reduced neural activity in the claustrum by 15% to 30%. This lowered activity also appeared to be associated with stronger subjective effects of the drug, such as emotional and mystical experiences. The researchers also found that psilocybin changed the way that the claustrum communicated with brain regions involved in hearing, attention, decision-making and remembering.
With the highly detailed imaging of the claustrum provided by fMRI, the researchers next hope to look at the mysterious brain region in people with certain psychiatric disorders such as depression and substance use disorder. The goal of these experiments will be to see what roles, if any, the claustrum plays in these conditions. The researchers also plan to observe the claustrum's activity when under the influence of other psychedelics, such as salvinorin A, a hallucinogen derived from a Mexican plant.
https://www.sciencedaily.com/releases/2020/06/200605121512.htm
Psychedelic drug use associated with reduced partner violence in men
Psychedelics may help improve emotion regulation and keep violent tendencies at bay
June 6, 2018
Science Daily/University of British Columbia Okanagan campus
In a new study published in the Journal of Psychopharmacology, researchers from UBC's Okanagan campus have discovered that men who have used psychedelic drugs in the past have a lower likelihood of engaging in violence against their intimate partners.
"Although use of certain drugs like alcohol, methamphetamine or cocaine is associated with increased aggression and partner violence, use of psychedelics appears to have the opposite effect," says clinical psychology graduate student and study lead author Michelle Thiessen. "We found that among men who have used psychedelics one or more times, the odds of engaging in partner violence was reduced by roughly half. That's significant."
Psychedelic drugs act on serotonin receptors in the brain. Classic psychedelics include lysergic acid diethylamide (LSD), psilocybin (magic mushrooms), mescaline, and dimethyltryptamine (DMT). The effects vary but can produce mystical experiences and changes in perception, emotion, cognition and the sense of self. Classic psychedelics are not considered to be addictive.
"Previous research from our lab that looked at men in the criminal justice system found that hallucinogen users were substantially less likely to perpetrate violence against their intimate partners," notes UBC professor and supervising author Zach Walsh. "Our new study is important because it suggests that these effects might also apply to the general population"
Thiessen, Walsh and colleagues Adele LaFrance and Brian Bird from Laurentian University based their results on an anonymous online survey of 1,266 people recruited from universities and through social media. Respondents were asked to disclose their lifetime use of LSD and psilocybin mushrooms and then complete a questionnaire that assessed multiple aspects of their emotion regulation.
"Past research found a clear association between psychedelic drug use and reduced partner violence, but the reasons for this effect remained unclear," says Thiessen. "We found that better ability to manage negative emotions may help explain why the hallucinogen users were less violent."
Thiessen says that her results could one day lead to novel treatments to reduce violence.
"These findings add to the literature on the positive use of psychedelics and suggest that future research should explore the potential for psychedelic therapies to help address the international public health priority of reducing domestic violence."
The study was published with funding in part from the Social Sciences and Humanities Research Council of Canada.
https://www.sciencedaily.com/releases/2018/06/180606093701.htm