Neuropsychopharmacology,
Journal Year:
2024,
Volume and Issue:
49(9), P. 1481 - 1490
Published: May 7, 2024
Abstract
Neural
states
of
impairment
from
intoxicating
substances,
including
cannabis,
are
poorly
understood.
Cannabinoid
1
receptors,
the
main
target
Δ9-tetrahydrocannabinol
(THC),
primary
cannabinoid
in
densely
localized
within
prefrontal
cortex;
therefore,
brain
regions
key
locations
to
examine
changes
that
characterize
acute
intoxication.
We
conducted
a
double-blind,
randomized,
cross-over
study
adults,
aged
18–55
years,
who
use
cannabis
regularly,
determine
effects
intoxication
on
cortex
resting-state
measures,
assessed
with
portable
functional
near-infrared
spectroscopy.
Participants
received
oral
THC
(10–80
mg,
individually
dosed
overcome
tolerance
and
achieve
intoxication)
identical
placebo,
randomized
for
order;
185
adults
were
128
completed
both
days
had
usable
data.
was
associated
expected
increases
subjective
ratings
(
ES
=
35.30,
p
<
0.001)
heart
rate
11.15,
0.001).
decreased
correlations
anticorrelations
static
connectivity
relative
weakest
among
those
reported
greater
severity
(RSFC
between
medial
PFC-ventromedial
PFC
DEQ
scores,
r
0.32,
0.001;
RSFC
bilateral
mPFC
–0.28,
Relative
increased
variability
(or
reduced
stability)
dynamic
at
0.001,
consistent
across
range
window
sizes.
Finally,
using
frequency
power
spectrum
analyses,
we
observed
widespread
spectral
0.073–0.1
Hz
0.039.
These
neural
features
suggest
disruptive
influence
dynamics
may
underlie
cognitive
impairing
detectable
imaging.
This
is
registered
Clinicaltrials.gov
(NCT03655717).
Journal of Psychopharmacology,
Journal Year:
2024,
Volume and Issue:
38(8), P. 701 - 711
Published: June 14, 2024
Some
recent
research
and
commentary
have
suggested
that
most
or
all
the
effects
reported
by
people
who
microdose
psychedelics
may
be
explained
expectations
placebo
effects.
In
this
rapid
review,
we
aimed
to
evaluate
strength
of
evidence
for
a
explanation
microdosing.
We
conducted
PubMed
search
studies
investigating
psychedelic
microdosing
with
controlled
doses
comparator.
identified
19
placebo-controlled
summarised
positive
null
findings
across
literature.
Risk
bias
was
assessed
using
Cochrane
risk-of-bias
tool
randomised
trials.
The
reviewed
papers
indicated
LSD
psilocybin
leads
changes
in
neurobiology,
physiology,
subjective
experience,
affect,
cognition
relative
placebo.
methodological
gaps
challenges
suggest
eight
reasons
why
current
claims
is
predominately
are
premature
possibly
wrong:
(1)
there
been
only
small
number
studies;
(2)
had
sample
sizes;
(3)
dose-dependent
effects;
(4)
investigated
doses;
(5)
too
small;
(6)
looked
at
non-clinical
populations;
(7)
so
far
susceptible
selection
bias;
(8)
measured
impact
expectancy
small.
Considering
available
evidence,
conclude
it
not
yet
possible
determine
whether
bioRxiv (Cold Spring Harbor Laboratory),
Journal Year:
2024,
Volume and Issue:
unknown
Published: Oct. 14, 2024
ABSTRACT
Psychedelics
have
robust
effects
on
acute
brain
function
and
long-term
behavior
but
whether
they
also
cause
enduring
functional
anatomical
changes
is
unknown.
In
a
placebo-controlled,
within-subjects,
electroencephalography,
magnetic
resonance
imaging
study
in
28
healthy,
entirely
psychedelic-naive
participants,
were
detected
from
one-hour
to
one-month
after
single
high-dose
(25
mg)
of
psilocybin.
Increases
cognitive
flexibility,
psychological
insight,
well-being
seen
at
one-month.
Diffusion
done
before
25mg
psilocybin
revealed
decreased
axial
diffusivity
bilaterally
prefrontal-subcortical
tracts
that
correlated
with
network
modularity
over
the
same
time
period.
Decreased
improved
well-being.
Increased
cortical
signal
entropy
1–
2-hours
post-dosing
predicted
Next-day
insight
mediated
relationship.
All
exclusive
psilocybin;
no
occurred
1mg
‘placebo’
dose.
Psychophysiology,
Journal Year:
2024,
Volume and Issue:
61(8)
Published: April 7, 2024
Abstract
Classic
psychedelics
are
able
to
profoundly
alter
the
state
of
consciousness
and
lead
acute
experiences
ego
dissolution
–
blurring
distinction
between
representations
self
external
world.
However,
whether
repeated
use
is
associated
with
more
prolonged
permanent
modifications
concept
remains
be
investigated.
Therefore,
we
conducted
a
preregistered,
cross‐sectional
study
in
which
experienced
users
(15
or
lifetime
psychedelics;
N
=
56)
were
compared
nonusers
(
57)
terms
neural
reactivity
Self‐name
(i.e.,
each
participant's
own
name)
stimulus,
known
robustly
activate
representation
self.
Two
control
stimuli
additionally
used:
an
Other‐name
as
passive
condition
no
reaction
was
required,
Target‐name
participants
provided
manual
response
thus
constituted
active
condition.
Analysis
amplitude
P300
ERP
component
evoked
by
Self‐
Target‐names
revealed
difference
nonusers.
psychedelic
exhibited
increased
during
perception
Other‐names.
In
addition,
comparison
nonusers,
smaller
increase
when
processing
task‐relevant
(in
relation
both
Other‐names).
our
data
suggests
that
regular
naturalistic
may
not
related
long‐term
changes
,
but
it
might
potentially
affect
allocation
attentional
resources
stimuli.
Philosophical Transactions of the Royal Society B Biological Sciences,
Journal Year:
2024,
Volume and Issue:
379(1915)
Published: Oct. 21, 2024
Executive
function
deficits,
common
in
psychiatric
disorders,
hinder
daily
activities
and
may
be
linked
to
diminished
neural
plasticity,
affecting
treatment
training
responsiveness.
In
this
pioneering
study,
we
evaluated
the
feasibility
preliminary
efficacy
of
psilocybin-assisted
frontal-midline
theta
neurofeedback
(NF),
a
neuromodulation
technique
leveraging
neuroplasticity,
improve
executive
functions
(EFs).
Thirty-seven
eligible
participants
were
randomized
into
an
experimental
group
(
