drugs controversy, danger, tradition. controversy and confusion uneasy boundary between legal and...
TRANSCRIPT
Controversy and confusion
• Uneasy boundary between legal and illegal, beneficial and harmful
• Many legal drugs injure in high amounts
• Many are addictive
• Many illegal drugs have medical uses
• Gateway drugs?
• Misinformation – often causes people to ignore real risks
background
• Humans use, and abuse, a wide variety of drugs which exert widely ranging effects
• Genetics play a role in our differing sensitivities to drugs
• Also, behavioral tendencies like impulsivity, novelty-seeking, hyperactivity, and variations in tolerance of stress, are important
Focus on the brain
• The release of dopamine and the pleasure which follows, tells us what we like
• This nudges us into eating, drinking, and other beneficial behaviors
• Years of research has revealed that ingesting many drugs also causes dopamine to be released, hi-jacking this natural reward system - to our peril
Underlying neurology
• The dopamine circuit begins in the ventral tegmental area (found at the top of the brain stem) which synthesizes dopamine which it passes to the
• Nucleus accumbens which then connects through its axons to areas of the frontal lobes
• Continued use of some drugs (opiates) causes neurons to shrink or otherwise work less effectively, forcing the user to rely on the drug for pleasure
but there is more
• Two other key brain structures are also involved
• The amygdala adds an emotional overtone to the desire for this manipulation of the reward circuit
• Even more importantly, the hippocampus makes sure that we remember the fun times associated with the drug, and the surroundings which accompany it
perspectives
• Many drugs decrease our ability to experience pleasure normally
• We then need them to make-up for what they have taken from us
• But these changes to our natural reward system can also be effected by other things such as gambling, video games, even sweets
alcohol
• World-wide and ancient use
• Part of many of our customs and traditions
• At the most basic level, simply a class of molecules
• We are concerned with ethanol – the type which people drink
Alcohol – the depressant that makes us act out
• While we typically link drinking alcohol with wild, reckless behavior, it is actually a depressant
• That’s because it, especially in high amounts, lessens our inhibitions by turning off our frontal lobes, increasing impulsivity/risk- taking behavior
• Excessive use leads to physical damage
tranquilizers
• Another type of depressant
• Help us relax, fall asleep and decrease muscle tension
• Barbiturates formerly commonly prescribed, now out of favor – addiction and other risks
• Benzodiazepines, such as valium, now hold sway – less addictive
bennies
• Great danger mixing them with alcohol • Both stimulate production of the neurotransmitter
GABA, which can inhibit the function of the medulla disrupting our breathing and heartbeat – a truly fatal mix
• Another aspect of these drugs is their use as “date rape” drugs – very inconspicuous
• Flunitrazepam/Rohypnol, or “roofies”• Induce euphoria, lack of inhibitions, amnesia
narcotics
• Produce drowsiness, insensitivity to pain and indifference to events
• Most commonly opiates
• Natural substances derived from the opium poppy
• Also synthetic compounds with similar chemical structures - methadone
Opiates - why they wreak such havoc
• Give users a warm, happy, contented feeling
• Heroin, morphine, methadone (synthetic)
• Virtually eliminate pain and anxiety but at the cost of apathy and fast addiction
• When the unnatural production of dopamine ceases the body cries out for it
• If denied, chemical withdrawal begins
Withdrawal from opiates
• During withdrawal all of the pleasant effects of the drug are reversed
• While before there was contentment now there is anxiety, before happiness now pain
• Worse yet, we need more - tolerance• Need for a “fix” causes desperate actions• theft, burglary, prostitution, shattered
lives, criminal prosecution
Long term effects
• Longitudinal studies paint a very bleak picture
• Of 581 users followed from 1962, nearly half were dead by 1997
• Survivors self-medicated, including cigarettes (67%)
• They also faced many health problems, including hypertension, liver and lung ills, etc.
stimulants
• Drugs which boost energy, alertness, activity and pleasant feelings
• Caffeine perhaps the most widely used drug? – 90%!
• Delivered through coffee, chocolate, soda, energy drinks, tea
• Can lead to dependency – headaches and drowsiness if denied
cocaine
• The drug of choice in the 80’s and beyond
• Derived from the leaves of the coca plant
• Creates a euphoric sense of happiness and increased activity
• Considered a stimulant because it turns off inhibitors, leading to an increase in behaviors
• But its use decreases over-all brain activity
More cocaine
• Very powerful, with many effects• Works by preventing a terminal button’s
synaptic vesicles from reabsorbing dopamine (reuptake) thus increasing its effects
• Also, kicks up norepinephrine and serotonin levels
• Works as an anesthetic ( as does lidocaine and Novocain) by stopping action potentials
Cocaine and addiction
• Usually taken in powder form with euphoria coming on within minutes and lasting for up to an hour
• If smoked through free basing, its effects emerge even faster
• The faster the pleasure, the quicker the addiction
Crack – addiction squared
• Crack cocaine, first developed in the mid- 80’s, provides even quicker, virtually instantaneous, pleasure
• Addictive after only a few uses
• Very expensive, readily addictive and quick to lose its effects
• It takes over lives, ruining careers and families
Long term
• While coke-triggered heart attacks and strokes strike occasionally, its residual damage is harder to assess
• Many who started to use it in the 80’s are now well into their 50’s and the number of addicts over 50 is set to explode, perhaps to over 4 million
• Effects are often worsened by overall neglect
marijuana
• CONTROVERSY
• Intensifies sensory experiences, induces euphoria, distorts time perception, also can lead to feelings of anxiety
• Formally known as Cannabis sativa
• Main psychoactive chemical is called THC
• Cultivated for at least 3000 years
The neurochemistry of marijuana
• Mimics a neurotransmitter called anandamide
• They attach to receptors which affect short term memory (on the hippocampus) which can make it difficult to remember events and learn
• Also they impact our muscle coordination by altering the normal functions of the cerebellum
Medical benefits
• Research shows that marijuana aids some medical conditions:
Chemotherapy problems – decreases vomiting, nausea, and anxiety
Aids-related wasting – improves appetite
Pain and muscle spasms – decreases these plus depression
Glaucoma – decreases pressure on eye
Why pot?
• It is so easy to administer• Puff by puff, the user can simply stop
when acceptable levels have been reached
• Low toxicity• Plus, its effects last no longer than 2 – 3
hours and no chance of overdose • But, since it is fat soluble, it can be
detected for 28-30 days after ingestion
The debate
• Life threatening?• Harmless?• Probably neither.• A gateway drug? (millions spent) very few move on to cocaine or heroin most used tobacco and alcohol first if marijuana disappeared would cocaine
and heroin?
withdrawal
• Is pot addictive?
tolerance doesn’t seem to develop
nothing compared to opiates, alcohol, or nicotine
very little proof of any residual effects
99% discontinue use without any withdrawal effects
Other risks
• Evidence is building of a relationship between early pot use and the development of psychosis
• Use before the age of 15 can make vulnerable teens much more likely to eventually develop serious mental illness
• Genetic predispositions activated by environmental conditions
A real danger?
• Amotivational syndrome
• Putting off important things till tomorrow because you got high today
• Coupled with well established barriers to learning, pot smoking can cause people to waste a lot of time and money
• Fact of fiction?
Long term
• A 2003 study stated that even among regular users there is no proof of irreversible cognitive damage
• Uncertain as to long range pulmonary disease and cancers though pot does contain carcinogens
hallucinogens
• Drugs which induce sensory distortions
• Can come from plants – mushrooms (psilocybin) or cactus (peyote)
• Also produced synthetically – LSD
• Famous for amazing intensification of sensations and experiences – from dream-like states to transcendent mystical events
Mescaline and psilocybin
• Mescaline, better known as peyote, is derived from a Chihuahan cactus found in Texas and Mexico
• It has been used medicinally and sacramentally for thousands of years
• US government allows its use in Native American religions
• Initial focus of Carlos Castenada’s “quest”
More peyote
• Users consume it in buttons• Many initially experience nausea which is
followed by feelings of physical energy (small doses) or visionary experiences which they view as a spiritual and physical blessing
• A recent study of regular Native American users found no harmful cognitive or psychological effects, and some gains!
Magic mushrooms
• Psilocybin, an active chemical compound in hundreds of mushrooms that causes hallucinogenic experiences
• Used world-wide especially by the Aztecs
• Can be smoked or simply eaten
• Castenada, and many others, sampled
• Most common natural hallucinogenic
lsd
• Officially lysergic acid diethylamide
• Accidentally discovered by a Swiss chemist, Albert Hoffman, in 1943
• Somehow ingesting it, he experienced an amazing shift in consciousness
• “An uninterrupted stream of fantastic images of extraordinary vividness and plasticity” passed before his eyes “ accompanied by an intense kaleidoscopic play of colors”
Further “research”
• Hoffman went on to try LSD on many more occasions
• These experiences were invariably pleasant except once, when tired, he mixed it with amphetamines and experienced history’s first “bad trip”
• Recently turned 100, he still considers LSD “medicine for the soul”
Then things got weird
• The word slowly spread until in the early 60’s it reached Timothy Leary, a maverick Harvard psychologist with extensive work with psilocybin
• Leary experimented with his graduate students and raved about LSD’s effects reporting profound mystical and spiritual experiences
• “Turn on. Tune in. Drop out.”• “The most dangerous man in America.”?
The serotonin connection
• LSD attaches to receptors usually used by serotonin
• It apparently stimulates the receptors in strange ways
• Change our typical perceptual filtering?
• Bad trips largely arise from the setting
• In secure environments, very unlikely
• Some suffer flashbacks, but still rare
ecstasy
• Also known as MDA or MDMA• Synthetic compounds which resemble
neurotransmitters and stimulate serotonin receptors
• Users report heightened intimacy and insight into relationships
• Many negative effects – confusion, anxiety• Evidence points towards damage to axons
devoted to serotonin
Crystal meth
• Also known as methamphetamine
• Causes extensive production of dopamine
• Ingestion leads to an almost instant tingly rush of sexiness, confidence and alertness
• But eventually, dopamine receptors are depleted and users feel unable to experience pleasure without more and more
A hurricane of shattered bodies and lives
• Addiction often follows with devastated families, lost jobs, ruined health, crime, etc
• Horrible physical aftermath – premature aging, skin sores, ruined teeth, wasting
• Burns victims overwhelm rural counties $$
• But for the Bush administration pot is still enemy #1 – Local governments disagree