psychedelics Flashcards
What’s the difference between true hallucinations and pseudo-hallucinations?
True hallucinations: Perceptions of things that are not real.
Pseudo-hallucinations: Altered perceptions of real things.
What is the relationship between psychedelics like LSD and serotonin?
LSD has a similar structure to serotonin, and it activates serotonin receptors in the brain, particularly the 5-HT1A and 5-HT2A receptors, which are involved in mood, perception, and visual processing.
What are the two main classes of monoamine neurotransmitters?
Catecholamines: Dopamine (Dopa), epinephrine (adrenaline), norepinephrine (noradrenaline)
Indoleamines: Melatonin, serotonin (from tryptophan)
How does LSD affect the serotonin system?
LSD activates the 5-HT1A and 5-HT2A receptors:
In the visual cortex, this activation modifies visual processes, contributing to hallucinations (e.g., Kanizsa figure – perceived shapes that aren’t there).
In the prefrontal cortex, it increases glutamate release, which may contribute to the overall effects.
What happens in the brain during an LSD trip?
The visual cortex becomes more active and receives increased blood flow, which correlates with the hallucination symptoms.
The Default Mode Network (DMN), which is active when you’re not focused on the outside world, becomes less active, contributing to the altered sense of self and perception.
What are some overlapping effects of hallucinogens?
Hallucinogens often produce very similar subjective effects across different drugs, particularly at high doses, which include altered sensory perceptions, altered time perception, and intense emotional experiences.
What is a mixed stimulant psychedelic drug?
A mixed stimulant psychedelic, like MDMA (Ecstasy), produces both psychostimulant effects (increased energy, euphoria) and hallucinations.
What are the effects of MDMA at different doses?
Low dose: Inhibits serotonin transporters and reverses serotonin flow, leading to an increase in serotonin levels without major effects on dopamine.
High dose: Also inhibits dopamine transporters, leading to an increased level of both serotonin and dopamine in the brain.
What happens with chronic MDMA use?
Chronic use can cause damage to serotonin receptors, leading to loss of serotonin and reduced serotonin activity, which may cause brain adaptations where the brain tries to stop synthesizing serotonin as a coping mechanism.
What is the MDMA rebound effect?
MDMA depletes serotonin and dopamine stores, and because it prevents reuptake, the brain is left with depleted stores. This can lead to short-term psychological effects such as depression, anxiety, and lethargy, which typically last about a day.
What are dissociative anesthetics and their effects?
Dissociative anesthetics like phencyclidine (PCP) and ketamine cause sedation, pain relief, and feelings of disconnection from the body.
