Drugs and the Brain

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Drugs and the Brain

• Neurons (Brain Cells)
• Neural Communication
• Psychoactive Drugs and Behavior

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Neuron

• Dendrite
• bushy, branching extensions of a neuron that
  receive messages and conduct impulses toward the
  cell body
• Axon
• the extension of a neuron, ending in branching
  terminal fibers (buttons), through which messages
  are sent to other neurons or to muscles or glands
• Myelin MY-uh-lin Sheath
• a layer of fatty cells segmentally encasing the
  fibers of many neurons
• Speeds neural impulses, quickening communication
  between neurons

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Neural Communication
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Neurotransmitters

• Some common neurotransmitters
• (among thousands)-
• Dopamine-influences movement, learning, attention
  emotion too much dopamine thought to play
  role in some symptoms of schizophrenia
• Serotonin-affects mood, hunger, sleep, arousal
  antidepressants like Prozac increase
  availability of serotonin
• Norepinephrine-plays role in alertness and
  arousal
• Acetylcholine-involved in muscle action, learning
  memory most abundant and one of best
  understood neurotransmitters
• Endorphins-naturally occurring opiates, help
  control pain

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We thought this was cool?
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Neural Communication
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Drugs and States of Consciousness

• Psychoactive Drugs
• mind altering chemicals
• they change how you perceive and feel
• perception is process of selecting, organizing
  interpreting info your senses take in
• Gives you ability to recognize meaningful things
  events
• (psychoactive drugs alter this!!!)
• legal and illegal psychoactive drugs
• psychological effects depend on dosage, form
  taken, expectations, personality of user
  situation

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Drug Tolerance

• Tolerance
• Decrease in effect of a drug with repeated use
• need larger dose of drug over time to obtain
  desired effect experienced with initial dose

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Drug Tolerance

• Example of tolerance
• -initial opiate intake?euphoria, pain relief
• -chronic opiate intake using same dose ?
  decreased euphoric pain relief effect
• -Have to increase dose of opiate to
• experience initial euphoric/pain relief
• effects

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Drug Tolerance

• Word tolerance deceiving..
• Body does not tolerate chronic drug use well-
• Chronic drug use damages brain and internal
  organs
• For Example liver of alcoholic works very hard
  to break down alcohol?increased metabolism ?
  decreased effect of drug ?increased intake
• Normal healthy cellular and chemical process
  damaged w/ repeated drug use
• Body does NOT tolerate repeated drug exposure
  well!

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Drug Dependence

• Psychological Dependence
• a psychological need to use a drug
• for example, to relieve negative emotions
• especially true for stress-relieving drugs
• Physical Dependence
• discomfort and distress that follow discontinued
  use of an addictive drug
• a physiological need for a drug to function w/in
  normal limits
• marked by unpleasant withdrawal symptoms
• Depends on drug-
• Stimulant withdrawal?CNS depression and lethargy
• Opiate withdrawal?severe flu-like symptoms

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Addiction

• Compulsive drug seeking behavior
• Control over drug use is lost
• 3 Misconceptions about addiction (believed to be
  myths by many drug researchers)
• 1) medical drugs (e.g. pain meds) are powerfully
  addictive
• 2) addictions cant be overcome voluntarily, but
  only through treatment
• 3) we can extend concept of addiction to include
  a spectrum of repetitive, pleasure-seeking
  behaviors (overeating, exercise, gambling, sex)

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Psychoactive Drugs

• 3 common Classes of Psychoactive Drugs
• stimulants
• hallucinogens
• depressants

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Stimulants

• Stimulants (uppers)
• drugs that stimulate neural activity, cause
  accelerated body functions along w/ elevated
  energy and mood changes, increased alertness, and
  decreased appetite
• caffeine
• nicotine
• amphetamines (speed)
• cocaine

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Stimulants

• Often used to stay awake, lose weight, boost mood
  or athletic performance
• Benefits come with a price
• Crash (fatigue, headaches, irritability,
  depression)
• W/ cocaine use, quickly go from 15-30 min of
  euphoria to crash
• Crack cocaine even briefer more intense high
  more intense crash, craving after several days
• stimulants are addictive

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Stimulants Cocaine

• Popularized by Freud in 1880s
• He suggested it as miracle drug for treatment of
  depression, indigestion, asthma, neurosis,
  syphilis, drug alcohol addiction.
• Based on Freuds endorsement
• Widely prescribed by physicians
• Appeared in Coca Cola for about 10 years

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Stimulants Caffeine

• Most widely consumed drug in world
• Found in many foods, drinks, meds
• coffee, tea, sodas, cocoa, chocolate, Vivarin,
  Anacin, Excedrin, No Doz, Midol, cold meds
• Rapidly absorbed following ingestion
• Reaches peak blood levels-30 min
• Peak concentration- about 2 hours

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Stimulants Caffeine

• Lethal dose 10 grams (1,000 cups coffee)
• Useful for migraines (in Excedrin)
• Can lead to increased urination
• Dehydrates, drink lots of water w/ caffeine
  ingestion
• Overuse anxiety, insomnia, hypertension,
  cardiac arrhythmias,GI disturbance
• Treatment-wean yourself off/decrease intake

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Stimulants Nicotine

• 1 of top 3 psychoactive drugs used in Western
  society (caffeine alcohol)
• Consumed in various forms cigarettes, cigars,
  pipe tobacco, chewing tobacco
• Mild stimulant
• Nausea and vomiting often seen w/ 1st use
• Chronic use rapidly results in tolerance
  physical dependence
• Responsible for many preventable health problems
• Heart disease, cancer, stroke, chronic lung
  disease, pneumonia, flu, atherosclerosis
• Responsible for approx. 1100 premature deaths in
  America per day (40,000 per year)

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Keep in mind..

• All psychoactive drugs, despite their
  differences, share common feature
• Trigger negative aftereffects that offset their
  immediate positive effects
• Aftereffects illustrate a general principle
• Emotions tend to produce opposing emotions, w/
  repetition, opposing emotions grow stronger
• As opposing negative aftereffects become
  stronger, need larger and larger doses of drug to
  produce desired high (tolerance), and the
  aftereffects worsen in the drugs absence
  (withdrawal). To switch off withdrawal, want to
  take more of the drug

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Mild to Severe Effects of Stimulants (see your
textbook p. 280 for a similar chart on different
drugs)
From Keith Trujillo lecture notes,
neuropsychopharmacology course
 
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Hallucinogens

• psychedelic (mind-altering) drugs that distort
  perceptions and evoke sensory images in the
  absence of sensory input (illusogens)
• LSD
• Marijuana
• Ecstasy
• Bufotenin (toad licking)
• Mescaline (peyote)
• PCP (angel dust)
• Ketamine (Special K)
• Ololuiqui (morning glory seeds)
• These and many others often derived from plant
  and animal products and historically used for
  religion or magic.

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Hallucinogens can produce

• perceptual distortions
• heightened sensory awareness
• sense of clarity
• profound thoughts/experiences
• feelings of empathy/unity
• religious experience
• various emotions

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HallucinogensPotential Adverse Effects

• bad trip (accompanied by anxiety, fear)
• chronic/intermittent psychotic states
• persistent depression
• worsening of pre-existing psychiatric disorder
• disruption of personality (burnout)
• flashbacks of hallucinations (post-hallucinogenic
  perceptual disorder)
• paranoia
• sudden mood changes
• unpredictable aggression
• amnesia
• confused thought
• schizophrenic-like effects
• unpredictable effects
• tolerance can develop

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Hallucinogens THC (marijuana)

• THC
• the major active ingredient in marijuana
• mild hallucinogen
• amplifies sensitivity to colors, sounds, tastes,
  smells
• impairs reaction time
• disrupts memory formation
• impairs motor coordination
• interferes with immediate recall of just learned
  info
• can intensify feelings of anxiousness or
  depression
• can produce feelings of pleasure/euphoria

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Hallucinogens THC (marijuana)

• changes brain chemistry
• may make brain more susceptible to cocaine and
  heroin addiction
• long term use may
• depress male sex hormone and sperm levels
• damage more than cigarette smoking
• hasten loss of brain cells
• cognitive effects outlast period of smoking
• thc and byproducts stay in body for month or more
• contrary to tolerance, w/ regular use, may result
  in sensitization (need less to get same initial
  high)

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Hallucinogens THC (marijuana)

• can be therapeutic
• if suffering pain and nausea (chemotherapy) or
  severe weight loss (AIDS), or eye pressure due
  to glaucoma, marijuana can relieve symptoms
• marijuana legalized for those purposes in some
  states (California Arizona, 1996)
• After 2 states legalized marijuana, fed govt.
  warned that doctors may still risk losing their
  license or face prosecution by prescribing it
  (small of people have federal approval to smoke
  marijuana for medical reasons govt. fears
  further liberalization of drug laws)
• Marijuana used illicitly by many glaucoma, cancer
  and AIDS sufferers who rely on it to control
  their symptoms or pain
• medical uses compromised by toxicity of
  marijuana smoke (cancer, lung damage, pregnancy
  complications)
• THC available in capsule form for nausea and as
  appetite stimulant

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Depressants

• Central Nervous System Depressants-reduce neural
  activity and slow body functions (alcohol,
  barbiturates, opiates)
• at moderate doses produce decrease in
• environmental awareness
• responses to sensory stimulation
• cognitive functioning
• spontaneity
• activity
• pain

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Depressants

• At higher doses, depressants lead to
• relief from anxiety
• disinhibition
• general anesthesia
• increased drowsiness
• lethargy
• amnesia
• seizures (inhibits seizures)
• hypnotic effects
• sedation
• hypnosis
• coma
• death

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Alcohol Consumption AmongCollege Students-
F.Y.I.(results from survey (Bachman, 1997))

• Approx. 90 of college students drink alcohol
• Approx. 75 drink alcohol each month
• College students drink more than youths who end
  their educ. after high school (those who arent
  college-bound smoke more)
• Average annual consumption of alcohol per student
  is 34 gallons
• Beer most common, w/ Amer. College students
  consuming almost 4 billion cans/year

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Alcohol Consumption AmongCollege Students- F.Y.I.

• Students in Northeast drink more than those in
  South or West
• 95 of violent crimes on college campuses ?
  alcohol/drug related
• 73 of assailants 55 of victims of rape had
  used alcohol or other drugs
• 2/3 of student suicides were legally drunk at
  time of act
• 90 of fatal fraternity hazing accidents involve
  drinking

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Alcohol Consumption AmongCollege Students- F.Y.I.

• Negative correlation between college grades and
  amount of alcohol consumed drinking ? grades ?
• Students w/ D or F average drink about 3X as much
  per week as A students
• Students w/ high academic standings drink less in
  virtually all contexts than their peers with low
  academic standing
• Alcohol and drug-related rates decline overall in
  mid-20s when serious responsibilities often kick
  in
• Being engaged, married, or remarried quickly
  brings down alcohol use

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Top 10 Reasons College Students Give for
Consuming AlcoholF.Y.I.(Adler Rosenberg, 1994)

• 1)increases my feelings of sociability
• 2)relieves anxiety or tension
• 3)makes me feel elated/euphoric
• 4)makes me less inhibited (in saying, thinking
  and doing things)
• 5)enables me to go along with my friends
• 6)enables me to experience different state of
  consciousness
• 7)makes me less inhibited sexually
• 8)enables me to stop worrying
• 9)alleviates depression
• 10)makes me less self-conscious

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Rohypnol-Date Rape Drug- F.Y.I.(Friend, T 1996
Manning, A 1996)

• 7-10 X more potent than valium
• produces fast-acting profound prolonged
  sedation, feeling of well-being, stm loss,
  paralysis of extremities
• legally prescribed in 64 countries for insomnia
  and for preoperative anesthesia
• not approved for use in U.S.
• smuggled into U.S. from Colombia or Mexico
• in 1990s became popular in U.S. teens and young
  adults as party drug
• it became tool of predators to spike drinks of
  unsuspecting victims of rape

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Rohypnol-Date Rape Drug - F.Y.I.

• various street names likes roofies
• many date rape drugs but none have exact
  characteristics of Rohypnol
• tasteless, colorless, odorless
• causes sedation w/in 15 minutes and effects
  further boosted by alcohol/marijuana
• victims report passing out and awakening during a
  sexual assault
• some have no memory of being raped, but evidence
  of it

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Rohypnol-Date Rape Drug- - F.Y.I.

• since 1996, DEA documented more that 2500 cases
  in 32 states
• in 1996, DEA declared Rohypnol a Schedule 1 drug,
  placing it in same category as heroin and LSD to
  combat increase in trafficking and possession
• 10-year prison term for simple smuggling offenses
• researcher Anita Manning offers advice
• Dont drink something you didnt open yourself
• Always watch your drink at bars and parties
• Never leave your drink unattended
• Stay with trusted friends so you cant be led
  away
• Dont take a drink that has candy in it