Drugs and behavior: Hallucinogens

other names for hallucinogens

phjantastica and psychotomimetics,

found in how many plants

over 90 species

subgroups

• serotonergic hallucinogens

• methylated amphetamines

• anticholinergic hallucinogens

• dissociative anesthetics

serotonergic hallucinogens

most taken orally. includes LSD, mescaline, psilocybin, morning glory seeds, and hawaiian baby woodroses. tolerance rapidly develops to most, and shows cross-tolerance.

history: Aztecs used them for religious ritual, western amazon used banisteriopsis and virola

duration of action (serotonergic hallucinogens)

8-14 hrs, except DMT 60 minutes

effects of serotonergic hallucinogens

sympathomimetic: pupil dilation, inc in heart rate, BP, temp, and sweating. changes in visual perception (synesthesia), mood changes, bizarre thoughts, magical thinking, good/bad trips

adverse effects serotonergic hallucinogens

• risk of fetal damage with extremely high doses

• panic or paranoid reactions

• flashbacks: re-experiencing some aspect of the hallucinogenic experience

• may precipitate psychosis or emotional disturbance in vulnerable people

methylated amphetamines

usually taken orally, can be injected or snorted, absorbed rapidly, lasts 6-8 hours, includes MDMA (ecstasy and molly), DOM, MDA, MDE. all influence (inc) serotonin, dopamine, and norepinephrine (block reuptake), only DOM produced prominent visual hallucinations.

history: developed in early 1900s, street use of DOM in late 1960s, used in psychopathology in 1980s. MDMA placed on schedule I in 1985, popular in raves (club drug).

physical effects of methylated amphetamines

increased heart rate and BP, pupil dilation, muscle tension and teeth grinding, increased body temp, appetite suppression, and insomnia

psychological effects of methylated amphetamines

euphoria, emotional warmth and empathy, lowered defensiveness, increased verbal behavior. similar effects to amphetamines.

withdrawal effects of methylated amphetamines

not dramatic, drowsiness and muscle pain, depression, paranoia, anxiety, and dissipate in a few days.

toxicity of MDMA

increasing ER admissions (in 2001), dehydration, heat exhaustion, muscle breakdown, kidney failure, stroke, seizures, heart attacks. usually after high or multiple doses. toxic effects from elevated body temp due to intense physical activity or high temp of clubs. drinking too many fluids may alter sodium balance, leading to collapse. tablets may be adulterated (in omaha many MDMA are really meth)

neurochemical effects of MDMA

animal studies show serotonin neurotoxicity of 20 mg/kg (higher than typical human use). tablet could be 70-100 mg

heavy MDMA use

longer serotonin activity than controls, more sleep problems, depressed mood, memory deficits. polydrug problem. worse attention and memory tasks, but no worse than marijuana

1980s

MDA and MDMA used in psychopathology

anticholinergic hallucinogens

atropine and scopolamine

dissociative anesthetics

PCP and ketamine

peak of LSD use

1996

1938

LSD was invented in switzerland

1950s

LSD tried in psychotherapy

early 1960s

celebrities endorsed LSD, usage increased

late 1960s

negative publicity of LSD

1970s and 1980s

usage declined, increased again in 1990s, and declined deeply since

one oral ingestion of LSD

25mg (micrograms)

LSD pharmacokinetics

most potent, absorbed and distributed rapidly (20-60 mins to effects), rapid metabolism and elimination in liver (half life is 3 hours). detectable in urine for only 72 hours.

mescaline

1/300 as potent as LSD

virola (DMT)

is snorted or smoked

lysergic acid amide

morning glory and hawaiian baby woodrose, 5-10% as potent as LSD.

magic mushrooms

psilocybe mexicana is most common. psilocybin cubensis grows on cow dung along US gulf coast. Psilocybin is primary active ingredient, was isolated by albert hofmann in 1958. dried mushrooms are 0.2-0.5% psilocybin.1% as potent as LSD

acute effects of psilocybin

(0.045-0.315 mg/kg) dose dependently induces intense changes in mood, perception, and thought. described as pleasurable, enriching, and nonthreatening. larger doses can cause headaches and strong feelings of dysphoria and anxiety in some individuals.

good friday experiment

2 groups of seminary students (not blinded). half got 30 mg of psilocybin; half placebo. 90% in psilocybin group reported religious or mystical experience. 10% in placebo group reported the same. mystic experiences are an important component of antidepressant effects.