Lecture 11/12- Hallucinogens Flashcards
(34 cards)
What are Hallucinogens?
Induce an altered state of consciousness, characterized by distortions of perception, hallucinations or visions, ecstasy, dissolution of self-boundaries and the experience of union with the world.
What can hallucinogens also be refered to as?
‘Psychedelics’ (mind revealing/opening)
What are the 2 types of Hallucinogens?
Classic hallucinogens
Dissociative anaesthetics
What are Classic hallucinogens?
Plant derived substances eg psilocybin (mushrooms) and mescaline (peyote cactus).
-Agonists at serotonin (5-HT) receptors. -Altered state of consciousness is primary effect
What are dissociative anaesthetics?
Synthetic drugs eg ketamine
-Produce anaesthesia (loss of sensation) at higher doses and altered states of consciousness at lower doses incl dissociation from environment.
-Non-competitive NMDA receptor antagonists.
What are the 5 primary dimensions with sub dimensions?
-Oceanic boundlessness
-Anxious ego-disintegration
-Visionary restructralisation
-Acoustic alterations
-Altered vigilance
What is Oceanic boundlessness?
Positively experienced loss of ego boundaries
eg Insightfulness, unity
What is anxious ego-disintegration?
Thought disorder and loss of self-control
eg Anxiety, impaired control
What is visionary restructrialisation?
Referring to perceptual alterations (visual illusions and hallucinations) and altered meaning of precepts
What is acoustic alterations and altered vigilance?
Hypersensitivity to auditory hallucinations
Why is it important to set expectations in subjective experience?
Psychopharmacological actions of hallucinogenic drugs may be less predictable than those of other drugs.
What are hallucinogenic effects dependent on?
The user’s expectations and the environment.
Eg expectations and environments that would foster religious or spiritual experiences increase the probability of the drug producing such an effect.
What do studies by Stanislav Grof (1975) and Barr et al (1972) suggest?
That an individual’s response to repeated administration of the same drug and dose may vary.
What is the historical background of hallucinogens?
-Have a longer history esp as part of ancient rituals
-Plant-derived hallucinogens and LSD entered Northern American and European mainstream culture in first half of 20th century. -PCP developed as anaesthetic in mid 1950s and ketamine synthesized as safer alternative in 1962 (still used as anaesthetic in humans)
How are hallucinogens used in research?
-Significant interest in researchers in understanding hallucinogenic drug actions and to exploit them clinically (either for mechanisms of altered states of consciousness or therapy use). -Ketamine approved as depressions treatment in US in 2019
What is Ecstasy (MDMA)
An amphetamine with strong effects on serotonin transmission
What properties does Ecstasy (MDMA) have?
-Has stimulant properties eg increasing alertness and ‘energy’
-Hallucinogenic-like properties which increase sociability and talkativeness which induces an ‘altered state on consciousness with emotional and sensual overtones’
How harmful are hallucinogenic drugs and MDMA?
Apart from potential distress caused by the subjective experiences induced by classical hallucinogenic drugs, these drugs cause otherwise virtually no physical harm and no dependence.
What can ecstasy and dissociative anaesthetics (Ketamine) cause?
What is the number of ecstasy related deaths?
Dependence and cause neurodegeneration, although it is debated if typical recreational usage and doses cause neurodegeneration.
130 in England, Wales, Scotland (2017)
What are the UK drug regulations?
Three Classes (A, B and C) to determine the penalties for offences such as supply, production and possession of a controlled drug.
Five schedules regulate the clinical use of controlled substances and their storage and labelling requirements.
What hallucinogens activate the serotonin (5HT2) receptors?
Indoleamine and phenethylamine hallucinogens
How does the serotonin system link to hallucinogens?
Serotonergic raphe nuclei in the midbrain innervate large parts of the brain, including many cortical and subcortical forebrain regions.
How does 5HT2A receptors link to hallucinogens?
-5HT2A receptors are G protein-coupled receptors; their activation mainly has stimulatory effects on the neuron (increased transmitter release and increased activity).
-5HT2A receptor activation may stimulate excitatory neurons, including in the prefrontal cortex, which may be critical for the hallucinogenic effects
How does MDMA (ecstasy) simulate serotonin release?
Stimulates serotonin release (probably by interaction with 5HT transporter) and some of MDMA’s subjective effects are mediated by 5HT2A receptors.
