PSYC62H3 Chapter Notes - Chapter 12: Hallucinogen Persisting Perception Disorder, Psychedelic Drug, Default Mode Network
Chapter 12: Psychedelic Drugs
• Psychedelic drugs: induce reality-altering experience consisting of hallucinations,
sensory distortions, or delusions
o “Mid epadig’
• 3 general categories:
o Hallucinogens
o Mixed stimulant-psychedelics
o Dissociative anesthetics
→ Halluinogens
• Produce hallucinations as their main pharmacological effects
• LSD
o Synthesized from lysergic acid
• Psilocybin
o Main psychoactive constituent in hallucinogenic mushrooms
o After administration psilocybin quickly converted into its metabolite psilocin
• Mescaline
o Found in peyote: small, spineless cactus native to southern NA
• Dimethyltryptamine (DMT)
o Found in South American plants
o Body also produces small amounts of DMT
LSD Ingestion and Effects
• Normally orally administered
• LSD = potent
• LSD sticks to paper, and recreational users ingest the drug by licking the paper
• Reaches peak absorption after an hour
• Cells in the liver metabolize LSD producing 2-oxo-3-hydroxy-LSD
LSD and the Serotonin NT System
• Cheial struture of LSD reseles serotoi’s heial struture
o LSD can act on serotonin receptors
o Functions as a receptor agonist with high binding affinity for 5-HT1A, 5-HT2a, 5-
HT6, 5-HT7
o LSD activates receptors located postsynaptically on other NT neurons, such as
glutamate and GABA neurons
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• These neurotransmission effects affect many sensory-processing systems in the brain
• In visual cortex, LSD activates both 5-HT1A and 5-HT-2A reeptors → odifies uer
of visual processes
• Model object completion: perception of object boundaries inferred from incomplete
representations of the object
o N170 waveform strongly associated with this
o Psilocybin inhibited both modal object completion and weakened N170
waveform amplitudes in specific areas of visual cortex
• LSD causes normally suppressed sensory info from the locus coeruleus to become more
refined and salient
• Chronic use may cause structural changes to parts of cerebral cortex
o Default ode etwork→ activity occurring in a series of brain structures during
times on non-goal directed activity or inattention
o Chronic use of hallucinogens affects this area
LSD’s Mild Phsiologial Effets ad Profoud Halluiogei Effets
• Primarily elicit subjective pharmacological effects
• At orall used doses → odest ireases i heart rate, ireases i pupil diaeter,
slight dizziness, mild nausea, diarrhea, or stomach ache
• True hallucination: pereptio of iages or souds that are’t real
• Pseudo-hallucination: altered perception of things that are real
o This is what LSD causes
• Trip: overall hallucinogenic experience
o Can be good or bad
o Good trip→ highly pleasant sensory distortions and pseudo-hallucinogens
▪ Users may experience feelings of enhanced perception or insightfulness
▪ May experience sesthesia→ experiencing sensory stimuli in an
incorrect sensory modality
• Ex: experiencing sounds when seeing colours
o Bad trip → disturbing true hallucinations, psychotic episodes, negative emotional
states, altered perceptions of time, and out-of-body sensations
• A person’s expetations and previous experienes an affet LSD’s sujetive effets
o Physical surroundings, current emotional state, comments made by friends, etc
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• Hypersuggestibility: state of easy influence by suggestions that can jeopardize reality
testing
Hallucinogens and Flashbacks
• Users may randomly experience striking memory of the previous trip
o Flashback OR hallucinogen persisting perception disorder
• Flashback: short, non-distressing recurrence of a previous trip
• Hallucinogen persisting perception disorder: recurring, longer-term, and unpleasant
experiences that are difficult to reverse
→ Mixed-Stimulant-Psychedelic Drugs
• Substance that exhibits both psychostimulant effects and hallucinations
• MDMA aka Ecstasy
o Ecstasy can be any stimulant or psychedelic that may contain only small
amounts, or even no amount, of MDMA
• MDMA also known as an entactogen (touching within) OR empathogen (enhanced
empathy)
o Users become friendlier, exhibit closeness with others, perceive greater insight
into their thoughts and emotions
• MDMA shares similar chemical structure with amphetamine and possess many of its
psychostimulant effects
o But it also produces LSD-like hallucinations
• Frequently used in raves
o Enhance the experience
• Users mainly consist of high school and college-age indvs
MDMA Therapeutic and Recreational Use
• Discovered in efforts to develop amphetamine derivatives
• Emerged as a recreational drug in 70s
o Ppl sought it for spiritual enlightenment, improving sensuality in relationships,
and pure enjoyment
• MDMA assisted therapy for patients with PTSD
MDMA Metabolism and the Length of Psychedelic Drug Effects
• Users prefer to administer orally
• MDMA readily absorbs through the gastrointestinal tract
• Reaches peak blood plasma levels after 2 hours
• Elimination half-life is approx 9 hours
• MDMA metabolized in liver primarily by CYP2D6 enzymes and to lesser extent by other
enzymes
o Deficiencies in CYP2D6 enzyme lead to MDMA accumulation in body
o Leads to prolonged drug effects and increased probability of adverse effects
occurring at low to moderate doses
o Certain SSRIs inhibit CYP2D6 activity
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Document Summary
Chapter 12: psychedelic drugs: psychedelic drugs: induce reality-altering experience consisting of hallucinations, sensory distortions, or delusions, mi(cid:374)d e(cid:454)pa(cid:374)di(cid:374)g", 3 general categories, hallucinogens, mixed stimulant-psychedelics, dissociative anesthetics. Hallu(cid:272)inogens: produce hallucinations as their main pharmacological effects. Lsd sticks to paper, and recreational users ingest the drug by licking the paper: normally orally administered, reaches peak absorption after an hour, cells in the liver metabolize lsd producing 2-oxo-3-hydroxy-lsd. Lsd and the serotonin nt system: che(cid:373)i(cid:272)al stru(cid:272)ture of lsd rese(cid:373)(cid:271)les seroto(cid:374)i(cid:374)"s (cid:272)he(cid:373)i(cid:272)al stru(cid:272)ture, lsd can act on serotonin receptors, functions as a receptor agonist with high binding affinity for 5-ht1a, 5-ht2a, 5- Ht6, 5-ht7: lsd activates receptors located postsynaptically on other nt neurons, such as glutamate and gaba neurons, these neurotransmission effects affect many sensory-processing systems in the brain. Indv may take mdma while also taking prescribed psychoactive medications higher doses. In crowded spaces, can lead to severe overheating and dehydration.
