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Chapter 12
Psychedelic Drugs:
Mescaline, LSD, and other
Hallucinogens
What is a psychedelic drug?

Any agent that causes alterations in
perception, cognition, and mood as its
primary psychological actions in the
presence of an otherwise clear
sensorium. (Abraham, Aldridge, and Gogia)
4 Classes of Psychedelic Drugs
Anticholinergic
 Catecholamine-like
 Serotonin-like
 Psychedelic anesthetics-(affect a
specific subclass of glutamate
receptors- NMDA receptors).

Difference between Mescaline
and LSD

Mescaline (more commonly known as
peyote) is a catecholamine-like psychedelic
drug. It produces an acute psychotomimetic
state with prominent effects on the visual
system when taken. Effects can last for
about 10 hours.
 LSD is a serotonin-like psychedelic drug. It
produces an alteration in thinking, emotion,
arousal, and self-image. Time is slowed
down. Visual alterations are the
characteristic phenomenon. Effects last for
about 6 to 8 hours.
More about LSD

The LSD-induced psychedelic experience typically occurs in
three phases:
1. The somatic phase occurs after absorption of the drug &
consists of CNS stimulation & autonomic changes that are
predominantly sympathomimetic in nature.
2. The sensory (or perceptual) phase is characterized by sensory
distortions and pseudohallucinations, which are the desired
effects by the drug user.
3. The psychic phase signals a maximum drug effect, with
changes in mood, disruption of thought processes, altered
perceptions of time, depersonalization, true hallucinations, and
psychotic episodes. Experiencing this phase is called a “bad
trip”.
Psychedelic Syndrome

Hallucinations manifest their impressive
alterations of mood, perception, and
thought.The sorting process of the
pontine raphe, a major center of
serotonin activity which filters stations
for incoming sensory stimuli, is
disrupted by such drugs and a surge of
sensory data and an overload of brain
circuits is caused.
Problems associated with LSD
use:

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Chronic or intermittent psychotic states
Persistent or recurrent major affective disorder
(depression)
Exacerbation of preexisting psychiatric illness
Disruption of personality or chronic brain syndrome
known as “burnout”
Post-hallucinogenic perceptual disorder or
“flashbacks” characterized by the periodic
hallucinogenic imagery months or even years after
the immediate effect of LSD has worn off.
How Phencyclidine (PCP) works:

Effects result of binding as noncompetitive
antagonists of the NMDA glutamate
receptors.
 Acute doses of PCP can induce a toxic
psychosis. Repeated doses induce a more
persistent schizophrenic symptomatology,
including psychosis, hallucinations, flattened
affect, delusions, formal thought disorder,
cognitive dysfunction, and social withdrawal.
Properties that characterize the
clinical usefulness of PCP and
ketamine:


PCP is an open channel blocker of the NMDA
receptor, transiently occluding the pore. It has a
promising strategy to prevent glutamate-mediated
neuronal cell death & associated disorders such as
stroke, epilepsy, and Huntington’s disease.
NMDA antagonists have also been proposed as
potentially advantageous as neuroprotective agents,
potentially useful for the treatment of CNS ischemia &
head trauma.
MDMA

MDMA (a.k.a. ecstasy, XTC, and Adam) is a
synthetic amphetamine derivative.
 Cross between stimulant and hallucinogen
 Enhanced mood, sense of well being,
increased emotional sensitiveness, little
anxiety, mild depersonalization and
derealization phenomena (mildly
hallucinogenic), changes in sense of space
and time, heightened sensory awareness,
increased psychomotor drive
MDMA problems and toxicities
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MDMA may be too dangerous for human use
Potent neurotoxin in animal studies
Memory impairment in humans
Fatalities during periods of intense activity/
skiing, dancing, etc.
hyperthermia, tachycardia, disorientation,
dilated pupils, convulsions, rigidity,
breakdown of skeletal muscles, kidney
failure, and death.
MDMA

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1.5% to 3.5% of 15 to 30 year olds have used
ecstasy within previous year
Early studies found generally self-limiting patterns of
use, low levels of intravenous use, and few adverse
health effects
Now extensive polydrug use the norm, high rates of
intravenous use, many physical, psychological,
financial, relationship, occupational problems
Combined use of MDMA with LSD (candyflipping)
appears to be increasing