2020 lecture 18

Introduction

  • Lecture number: 18

  • Course: Psychology 2028

  • Topic: Hallucinogens and designer drugs

  • Hallucinogens are drugs defined by their ability to cause hallucinations or delirium-like effects.

  • Early use: Many hallucinogens were originally consumed in natural forms, such as plants and fungi.

Classification of Hallucinogens

  • Hallucinogens are categorized into four main categories based on neurochemical similarities:

    1. Cholinergic hallucinogens

    2. Serotonergic hallucinogens

    3. Noradrenergic (methylated amphetamines)

    4. Miscellaneous hallucinogens

  • Discussion will focus on the first two categories primarily.

Cholinergic Hallucinogens

Overview

  • Cholinergic hallucinogens can either activate (agonists) or block (antagonists) cholinergic activity.

  • They typically induce a delirium or dream-like state rather than true hallucinations, and can be fatal due to interference with vital functions.

  • Chemical warfare agents can fit into this category as well due to their cholinergic action.

Agonists

Examples

  1. Amanita muscaria (Fly agaric mushroom)

    • Found in temperate zones, particularly Scandinavia.

    • Characteristics: Bright red with white speckles.

    • Historical use: Consumed by Vikings to create feelings of invincibility (berserkers).

    • Psychoactive substances: Ibotenic acid and muscimol.

    • Excretion: Largely unchanged, leading to communal practices where urine is consumed.

    • Effects:

      • Low doses produce euphoria.

      • Higher doses lead to detachment, dissociation, and increased power sensation.

      • Physiological effects include increased secretions, pupil constriction, and potentially fatal overdoses.

  2. Ibogaine

    • Found in Gabon, used as a stimulant by local tribes.

    • Historical context: Marketed in France as a stimulant (Lamborine).

    • Associated with helping individuals understand their addiction issues, though controlled studies reveal no greater effectiveness than placebo.

Antagonists

Examples

  1. Atropa belladonna (Deadly nightshade)

    • Contains atropine as the primary psychoactive substance.

    • Historical context: Used as poison and beauty enhancer; dilated pupils were considered attractive.

    • Effects include drying secretions, sedative effects, and at higher doses, delirium and amnesia.

  2. Datura (Jamestown weed, thorn apple, devil's trumpet)

    • Contains atropine, scopolamine, and hyoscyamine.

    • Effects include dreamlike states, amnesia, delirium, and potential breathability for asthma.

    • Young individuals sometimes misuse it leading to medical emergencies.

  3. Mandragora (Mandrake plant)

    • Contains atropine and similar substances as Datura.

    • Folklore: Mythological roots connecting it to hanged men's semen and magical properties.

    • Effects mirror those of other cholinergic antagonists, leading to profound sedation and possibly hallucinations.

Serotonergic Hallucinogens

  • These drugs resemble serotonin biochemically and act as agonists at serotonergic receptors (5-HT).

  • Notable serotonergic hallucinogens include LSD, which is often considered the prototypical hallucinogen.

LSD (Lysergic acid diethylamide)

  • Origins: Synthesized from lysergic acid amide from the ergot fungus.

  • Discovery: Accidental self-administration by Albert Hoffman.

  • Effects: Initially experienced as a low dose (250 micrograms), with recreational doses typically around 50 micrograms today.

    • Historical Usage: Popular in the 1960s–70s, with notable cultural influences.

  • Potency: Remarkable in its effects, with significant hallucinogenic properties experienced as low as a grain of salt (50 micrograms).

Effects of LSD

  • Physical Effects:

    • Activation of sympathetic nervous system: Increased heart rate, pupil dilation.

    • Analgesic properties similar to opiates.

  • Visual/Perceptual Effects:

    • Objects appear to pulse or move.

    • Object trails: Visual appearing to follow fast-moving objects.

    • Form constants: Reports of geometric patterns such as honeycombs.

    • Synesthesia: Mixing of sensory modalities (e.g., seeing music).

    • Altered perception of time and ego disintegration: Loss of sense of self and merger with surroundings.

Historical Use and Cultural Impact

  • Sites of experimentation and cultural aspects associated with LSD use, particularly in relation to psychotherapy and modern psychedelic-assisted therapy.

  • Public perception shifted after government interventions in the 1960s aimed at controlling recreational use, leading to LSD being classified as a schedule one substance due to perceived dangers and abuse potential.

Conclusion

  • The lecture covered classifications, effects, and implications of hallucinogenic drugs, focusing on cholinergic and serotonergic types.

  • Further discussions will continue on the other categories of hallucinogens in upcoming lectures.