Recent Studies
Users of magic mushrooms — a term that describes
varieties of mushrooms that contain the psychoactive substance psilocybin —
often experience intense elation, an altered perception of reality, and
hallucinations (also known as “tripping”).
Psychedelic mushrooms may point to new ways to treat
depression, suggest two small brain imaging studies that seem to show how
psilocybin — the active ingredient in such mushrooms — affects the brain.
One study included 30 healthy people who had psilocybin
inserted into their blood while magnetic resonance imaging (MRI) scanners
measured changes in their brain activity. The scans revealed that psilocybin
caused decreased activity in what the researchers described as the brain's
"hub" regions — areas especially well-connected with other areas.
The second study included 10 healthy volunteers and found
that psilocybin boosted their recall of personal memories and their emotional
well-being for up to two weeks. The researchers said this suggests that
psilocybin might prove useful as an adjunct to psychotherapy.
A study published in 2014 found that people with anxiety
who received a single psilocybin treatment had lower depression scores six
months later. David Nutt, who is with the Department of Medicine at Imperial
College London, was the senior author of both of the new studies.
"Psychedelics
are thought of as 'mind-expanding' drugs, so it has commonly been assumed that
they work by increasing brain activity, but surprisingly, we found that
psilocybin actually caused activity to decrease in areas that have the densest
connections with other areas," Nutt said in a college news release.
"These hubs constrain our experience of the world and keep it orderly. We
now know that deactivating these regions leads to a state in which the world is
experienced as strange."
The impact of psilocybin reported by the study
participants — such as seeing "geometric" patterns, experiencing an
altered sense of time and space, and unusual physical sensations — correlated
with a decreased flow of oxygen and blood to parts in the brain's posterior
cingulate cortex and medial prefrontal cortex (mPFC), the study authors said.
It has thought that the posterior cingulate cortex plays
a role in consciousness and self-identity. Research has shown the medial
prefrontal cortex to be especially active in people struggling with depression,
so psilocybin's effect on this area of the brain could be responsible for some
of the antidepressant effects reported in previous research, the study authors
said.
Nutt and his colleagues also found that psilocybin
reduced blood flow in the hypothalamus, where blood flow increases in people
with cluster headaches. Some headache sufferers have reported that psilocybin improved
their symptoms.
"Psilocybin was used extensively in psychotherapy in
the 1950s, but the biological rationale for its use has not been properly
investigated until now. Our findings support the idea that psilocybin
facilitates access to personal memories and emotions," Dr. Robin
Carhart-Harris, from the Department of Medicine at Imperial College London, and
first author of both studies, said in the news release.
"Previous studies have suggested that psilocybin can
improve people's sense of emotional well-being and even reduce depression in
people with anxiety. This is consistent with our finding that psilocybin
decreases mPFC activity, as many effective depression treatments do. The
effects need to be investigated further and ours was only a small study, but we
are interested in exploring psilocybin's potential as a therapeutic tool,"
Carhart-Harris added.
The study authors reiterated that both trials contained
small numbers of participants, and further research into psilocybin's effects
on the brain is needed.
Previous Studies
The main focus of one of the older studies was related to
the exploration of the similarities between hallucinogenic experiences and the
life-changing revelations, reported throughout history by religious mystics and
those who meditate. These similarities have been identified in neural imaging
studies conducted by Swiss researchers and in experiments led by Roland
Griffiths, a professor of behavioral biology at Johns Hopkins.
In one of Dr. Griffiths’s first studies, involving 36
people with no serious physical or emotional problems, he and colleagues found
that psilocybin could induce what the experimental subjects described as a
profound spiritual experience with lasting positive effects for most of them.
None had had any previous experience with hallucinogens, and none were even
sure what drug was being administered.
To make the experiment double blind, neither the subjects
nor the two experts monitoring them knew whether the subjects were receiving a
placebo, psilocybin or another drug like Ritalin, nicotine, caffeine or an
amphetamine. Although veterans of the ’60s psychedelic culture may have a hard
time believing it, Dr. Griffiths said, that even the monitors sometimes could
not tell from the reactions whether the person had taken psilocybin or Ritalin.
The monitors sometimes had to console people through
periods of anxiety, Dr. Griffiths said, but these were generally short-lived,
and none of the people reported any serious negative effects. In a survey
conducted two months later, the people who received psilocybin reported
significantly more improvements in their general feelings and behavior than did
the members of the control group.
The findings were repeated in another follow-up survey,
taken 14 months after the experiment. At that point, most of the psilocybin
subjects once again expressed more satisfaction with their lives and rated the
experience as one of the five most meaningful events of their lives.
Since that study, which was published in 2008, Dr.
Griffiths and his colleagues have gone on to give psilocybin to people dealing
with cancer and depression, like Dr. Martin, the retired psychologist from
Vancouver. Dr. Martin’s experience is fairly typical, Dr. Griffiths said: an
improved outlook on life after an experience in which the boundaries between
the self and others disappear.
Magic Mushrooms to
become Mainstream Antidepressant?
Depression is estimated to affect more than 350 million
people around the world, according to the World Health Organization. The
current pharmaceutical approach to treatment is with selective serotonin
re-uptake inhibitors (SSRIs), such as Prozac, which increase levels of
serotonin in the brain to improve moods. But SSRIs are not effective in
everyone, take time to show an effect and are generally prescribed for long
periods of time to maintain their effect.
David Nutt thinks psilocybin could be a game-changer,
used as part of a therapeutic package where the mind-altering and confronting
nature of psychedelics are combined with therapy to treat people within just
one or two doses of treatment. "We've never had drugs before with an
instant effect. This could create a paradigm shift to help people into a
different state of thinking that they can then stay in," he says.
But he stresses that psilocybin should be administered
with professional support as part of medical therapy.
Psilocybin is illegal in many countries and in the United
States, it is considered a Schedule 1 drug. Schedule 1 drugs "have a high
potential for abuse and serve no legitimate medical purpose in the United
States," according to the Department of Justice.
The U.S. National Institute of Drug Abuse says that
long-term negative effects such as flashbacks, a risk of psychiatric illness
and impaired memory have been described in case reports. Some people have
frightening experiences while on psilocybin and can experience panic reactions,
which may cause them harm to themselves or others.
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