Drugs & ConsciousnessDrugs & Consciousness

Drugs & the BrainDrugs & the Brain• Blood brain barrier Blood brain barrier – –

layer of capillaries that layer of capillaries that protect the brainprotect the brain

• Psychoactive drugsPsychoactive drugs – – small enough to pass small enough to pass through blood-brain through blood-brain barrierbarrier

Change our Change our perceptions & moods by perceptions & moods by acting on neurons & acting on neurons & neurotransmitters in the neurotransmitters in the brainbrain

Remember that drugs are Remember that drugs are either….either….

• Agonists Agonists • Enhance NT’s effect by causing it to be released, Enhance NT’s effect by causing it to be released,

mimicking it, or by flooding the synapse & over-mimicking it, or by flooding the synapse & over-stimulating receiving cellstimulating receiving cell

• AntagonistsAntagonists• Block NT from being released, block it from Block NT from being released, block it from

being receivedbeing received

If a drug is used often, a If a drug is used often, a tolerancetolerance is created is created for the drug.for the drug.- Thus you need more of the drug to feel the same - Thus you need more of the drug to feel the same effect.effect.

If you stop using a drug you can develop If you stop using a drug you can develop withdrawal symptomswithdrawal symptoms..

Addiction – Compulsive Cravings Addiction – Compulsive Cravings Despite Adverse Effects Despite Adverse Effects

• Psychological Psychological dependencedependence– Used to relieve Used to relieve

stress or negative stress or negative emotionsemotions

• Physical Physical dependencedependence– User feels physical User feels physical

pain & intense pain & intense cravings when not cravings when not taking drugtaking drug

DepressantsDepressants• Slow down body Slow down body

processes by calming processes by calming neural activityneural activity

Depressants Depressants include:include:

• AlcoholAlcohol• Anxiolytics Anxiolytics

(barbiturates and (barbiturates and tranquilizers)tranquilizers)

• OpiatesOpiates

StimulantsStimulants

• Speed up body Speed up body processes by processes by exciting neural exciting neural activityactivity

• More powerful ones More powerful ones (like cocaine) give (like cocaine) give people feelings of people feelings of invincibility.invincibility.

• Caffeine, nicotineCaffeine, nicotine

HallucinogensHallucinogens• PsychedelicsPsychedelics• Causes changes in Causes changes in

perceptions of realityperceptions of reality• Evoke sensory Evoke sensory

images in absence of images in absence of sensory inputsensory input

• Reverse tolerance or Reverse tolerance or synergistic effect synergistic effect (less is needed to (less is needed to produce same effect produce same effect if used often)if used often)

Barbiturates (Tranquilizers)Barbiturates (Tranquilizers)• Depress NS activityDepress NS activity• Agonist for GABAAgonist for GABA• Induces sleep, reduces anxietyInduces sleep, reduces anxiety• Impairs memory & judgmentImpairs memory & judgment• Possible deathPossible death

Caffeine/NicotineCaffeine/Nicotine• Caffeine – most widely consumed drugCaffeine – most widely consumed drug

– Agonist for epinephrineAgonist for epinephrine– Agonist for dopamine Agonist for dopamine

(in prefrontal cortex)(in prefrontal cortex)– Tolerance if used oftenTolerance if used often– Effects include anxiety, Effects include anxiety,

restlessness, insomniarestlessness, insomnia

• NicotineNicotine– Agonist for ACh (acetylcholine) and dopamineAgonist for ACh (acetylcholine) and dopamine– Reduces circulation, increases heart rate & blood Reduces circulation, increases heart rate & blood

pressure, suppresses appetite, reduces stresspressure, suppresses appetite, reduces stress

Mouse PartyMouse Party• Go to Go to

http://learn.genetics.utah.edu/content/addiction/drugs/mouse.html to fill out the rest of the types of drugs (besides to fill out the rest of the types of drugs (besides barbiturates/tranquilizers, caffeine/nicotine, barbiturates/tranquilizers, caffeine/nicotine, which were described above)which were described above)

Other Negative Effects of Other Negative Effects of Marijuana UseMarijuana Use

• Harder on lungs than cigarette smoke Harder on lungs than cigarette smoke (Wu et al.)(Wu et al.)

• Brain cell loss accelerates with large doses Brain cell loss accelerates with large doses (Landfield et (Landfield et al.)al.)

• Memory impaired long after marijuana’s effect ahs Memory impaired long after marijuana’s effect ahs worn off worn off (Pope & Yurgelun-Todd; Smith)(Pope & Yurgelun-Todd; Smith)

• Marijuana suppresses immune system Marijuana suppresses immune system (Childers & (Childers & Breivogel)Breivogel)

• Lowers testosterone and sperm count in men Lowers testosterone and sperm count in men ((http://www.pbs.org/thebotanyofdesire/altering-consciousness.php) )

BIOPSYCHOSOCIAL APPROACHBIOPSYCHOSOCIAL APPROACH

• Biological Biological InfluencesInfluences– Genetic Genetic

predispositionspredispositions• Identical twins = Identical twins =

increased risk if one increased risk if one has addictionhas addiction

• Adopted more Adopted more susceptible if susceptible if biological parent biological parent used drugsused drugs

• Psychological Inf.Psychological Inf.– DepressionDepression– Stress or feelings of failureStress or feelings of failure– Reinforcement or Reinforcement or

observational learningobservational learning

• Social/Cultural Inf.Social/Cultural Inf.– Society’s expectations & Society’s expectations &

acceptance/lack of acceptance/lack of – Peers influence drug use Peers influence drug use

(more likely to use if (more likely to use if friends do)friends do)

PreventionPrevention• Education is related to drug Education is related to drug

use. use. Roughly 15% of U.S. Roughly 15% of U.S. college dropouts smoke, college dropouts smoke, and 42% of high school and 42% of high school dropouts smoke (Ladd, dropouts smoke (Ladd, 1998)1998)

• Hope matters. Hope matters. Those who Those who believe their lives are believe their lives are meaningless are more meaningless are more likely to use drugs likely to use drugs (Newcomb & Harlow, (Newcomb & Harlow, 1986).1986).

• Genetics plays a role. Genetics plays a role. Gene has been found to Gene has been found to occur more often among occur more often among alcohol-dependent alcohol-dependent people (Noble, 1993)people (Noble, 1993)

• Peers count. Peers count. If the If the friends you hang out friends you hang out with DON’T use drugs, with DON’T use drugs, there is a good chance there is a good chance you won’t either!you won’t either!