Psychedelics (Lect 5)

Question 1

Classic psychedelics/hallucinogens

Answer 1

Psychedelic: “Mind revealing”
hallucinogen: causing hallucinations

LSD: derivative of lysergic acid found in fungus
Psilocybin: found in magic mushrooms

Question 2

Acute subjective effects lasting several hours

Answer 2

• alterations in perception
• oceanic boundlessness ( + feelings of depersonalization, altered time and space)
• anxious ego dissection ( - feelings of depersonalizatio, loss of sense of self and control)

Question 3

Mechanisms for psychedelic effects

Answer 3

• indole ring structure
• one would think it involves serotonin but simply increasing or decreasing 5-HT levels foes not produce psychedelic effects
• disruption of PFC activity (higher cognitions sense of self)
• disruption of thalamus activity (sensory relay station) could be basis for psychedelic experiences
• increase in functional connectivity between brain areas

Question 4

Psychedelics in therapy

Answer 4

• research suggests positive effects for LSD & psilocybin in psychotherapy
• in treating addictions, OCD, depression, anxiety
• used to facilitate and intensify therapeutic processes but do not act as a replacement (Majic et al, 2015)

issues:

• not enough research
• not easy to control for placebo effects
• how are long lasting effects produced?

Question 5

Percentages

Answer 5

61% say: like having a deep mystical or religious experience

79% say: increased sense of self, well-being, life satisfaction

Question 6

Ketamine

Answer 6

• glutamate agonist, blocks excitatory effects of glutamate

- used as general anesthetic and sedative especially in young children

Question 7

effects of ketamine:

Answer 7

different to classic psychedelics

• similar to being drunk (euphoria, dizziness)
• disordered thoughts + speech
• memory impairments
• perceptual distortions
• delusional thinking, often paranoia

Scores increase on BPRS in healthy subjects when having intravenous ketamine

Question 8

Ketamine + depression

Answer 8

Rasmussen, 2016)

• rapid antidepressant effects in patients with MDD
• effects already seen a few hours after
• enhanced mood can last for days

issues:

• little evidence for lasting effect after first dose
• experience and antidepressant rather show a casual relationship than correlations
• prescriptions could raise safety concerns

Question 9

Study on Ketamine and depression

Answer 9

Fiefel et al (2017)

• patients had treatment resistant depression
• scores fell from 35 (severe) to 15 (mild) in one week after ketamine infusion