The Use and Abuse of Psychoactive Drugs

1. The Use and Abuseof Psychoactive Drugs

2. Nucleus accumbens • The nucleus accumbens, part of the limbic system plays a role in sexual arousal and the "high" derived from certain recreational drugs. These responses are heavily modulated by dopaminergicprojections from the limbic system.

4. Lobotomy of Phineas Gage • Ventromedial region of both frontal lobes • Personality change • irreverent, profane • Prefrontal cortex functions • planning, moral judgement, and emotional control

5. There is a Pleasure Center! • Rats in Skinner boxes with metal electrodes implanted into their nucleus accumbens will repeatedly press a lever which activates this region, and will do so in preference over food and water, eventually dying from exhaustion. In rodent physiology, scientists reason that the medial forebrain bundle is the pleasure center of rats( and humans). If a rat is given the choice between stimulating the forebrain or eating, it will choose stimulation to the point of exhaustion.

7. Why Study Drugs In Health Science? • Mainly to Become Aware of the Drug Addiction that may result from some drugs.

8. What Constitutes Addictive Behavior?

9. Addictive Behavior • Reinforcement- gives person pleasure • Compulsion or craving- person feel need to do it again • Loss of control- Persons often denies he has problem • Escalation- person gives more time to behavior • Negative Consequences-interferes w/ life

10. Why Teach About Drug Use? • 1. Drugs Can Be Addictive • 2. Drugs Can Cause Negative Side Effects Some with Short-Term Use Most with Long-Term Use • We Don’t Know All of the Long-Term Consequences of Many of the Drugs. • 3. Drugs can impair judgment; this causes higher risk: for auto accidents; engagement in unsafe sex, violence; more likely to be involved in an accident involving drowning, falling aggression and sexual assault.

11. Definition for DRUG Chemicals, other than food, intended to affect the structure and function of the body

12. Who is susceptible? • Anyone who has an addictive personality. • Habits that get out of control. • Negative impact on health. • Moral weakness v. brain biochemistry. • Actions increase tolerance. Yes, some people have more genetic predispositions to addictions!

13. Just a Bit of Drug History… • How Long Have Drugs Been Around? • Purpose? Function? • Where Do Drugs Come From? • How Do We Define a Drug Anyway?

14. The First Drugs Came from Plants • Plants were used in early humans in either of 2 ways: • Religious Ceremonies ( People believed that be consuming the drug they could communicate with God) 2. A Plant or its extract was used Medicinally

15. Active Ingredient • The part of the plant for pharmalogical effect is called the ACTIVE INGREDIENT • Examples: Morphine and Codeine are Active Ingredients of the plant Opium • They are NARCARTIC analgesics

16. TODAY…Still, most medicine comes from Plants…..Pretty Flowers Give Heart Medicine • Digitalis (Otherwise Known as Foxglove) The active ingredient here is Digitoxin, a heart medicine.

17. Peyote

18. Peyote: A Trip • Known to the Aztecs , who considered this hallucinogen a divine messenger. • In 1692, Indians established the mission El Santo de Jesus Peyotes • Slice and Dry Buttons/ 4-12 are ingested • At ritual…Period of meditation followed by periods of nausea and vomiting BUT they would see>>> VISIONS of Kaleidoscopes of jewels ( Lasts 6-10 hours)

19. Animal Sources Too • Best and Banting discovered they could make dogs diabetic by surgically removing their pancreases • Then curing the dogs by injecting them with extracts from the pancreas ie. Insulin. • BEEF and PORK pancreas are sources for most of insulin sold today.

20. What are psychoactive drugs? • Any drug that alters your state of mind. • Your perceptions. • Your experience. • Natural or man-made

21. Drug Abuse • Drug Abuse involves behavior addiction as well as chemical addiction. • Psychoactive Drug- a drug that alters one’s state of consciousness or can causes intoxication. • Addictive Behavior- are behaviors that have gotten out of control , with resulting negative effects on one’s health. All psychoactive drug are addictive because of the way they work in the brain.

22. Drug Terms • Tolerance- A physical adaptation of a substance that causes it to become less effective with repeated use. YOU NEED MORE EACH TIME TO GET THE SAME EFFECT! • Dependence- Occurs when person is so physically attached to drug she/he can’t live comfortably with/out it. See APA criteria in text. This person has withdrawal when drug is taken away • Withdrawal- Physical symptoms such as nausea, tremors …pain…can be dangerous.

23. Different Ways To Take Drugs • Intravenous injection, also called Mainlining (Most Effective Way) • Subcutaneous- under the skin • Dermal or subdermal absorption- (topical) can be placed on a stamp or suppository. LSD . • Swallow ( pill) • Smoke it • Inhale it

24. How Drugs Affect The Body: Drug Factors: (5) • 1. Pharmacological Properties : of the drug its overall effects on a person. This includes how it effects the person’s body chemistry, behavior and psychology.

25. Cont. of Drug Factors • 2) Dose-response Function- Relationship between dose taken and intensity of effect. • 3) Time-Action Function- How much time has elapsed and the intensity of effect. • )

26. Cont. of Drug Factors • 4) Drug Use History- Influences the effects of and response to a drug. ( Meaning that the user may have to refrain from using a drug for a while to get the same effect from a given dosage) • 5) Method of Use-Affects the strength of response ( swallow pill , inhale smoke or IV

28. The Neuron

29. STRUCTURE and FUNCTION NEURONS/ The Synaptic Cleft

31. NEUROTRANSMITTERS • Neurotransmitter - A chemical messenger released from the synaptic terminal of a neuron at a chemical synapse that diffuses across the synaptic left and binds to and stimulates the post-synaptic membrane. • Examples of neurotransmitters are epinephrine, dopamine, seratonin and acetylcholine. • When in the neuron, neurontransmitters are stored in vessicles.

32. Drugs & Reward • Most drugs of abuse seem to activate “reward” circuit(s) in the brain • Dopamine is a (the) principle one • Reward circuit(s) important for normal functioning & learning • Food, sex, & other necessary activities that are enjoyable (interacting with others, mastering a task, etc.) • All (most) behavior is channeled through these reward circuit(s) – do not have completely difference systems for sex, hunger, etc. • Recent research suggests that it is possible to separate systems – “liking” vs. “wanting” • “Liking” - system responsible for pleasure • “Wanting” – system that drives behavior

33. So How To Drugs Work? • Most drugs, natural and synthetic , work on specific neurotransmitter systems of the brain. • Cocaine and amphetamines block reuptake of dopamine • Benzodiaepine tranquilizers work by binding and AUGMENTING the natural action of receptors for the inhibitory neurotransmitter. • SSRIs like Prozac work by inhibiting reuptake of released serotonin

34. From Synapse to Receptor Site • Different Drugs have different “receptor sites” in the Brain for the NT. • NT gives a Euphoria at the site in brain. • This is often thought of as a “reward pathway”.

35. How Cocaine Causes Euphoria It is believed that cocaine boosts dopamine release and blocks its reuptake by dopamine transporters. This leaves more dopamine saturating synaptic clefts to overstimulate critical brain sites which cause the sensation of euphoria.

36. How Ecstasy Works

37. How Ecstasy Works • Ecstasy affects neurons that produce the neurotransmitter called SEROTONIN. • Normally, Serotonin, stored in vesicles, is released into synapse at a “progressive rate”. The this chemical is then absorbed by receptors of the adjacent neuron which causes an electrical signal to propagate. The appropriate area of the brain is stimulated.

38. When Ecstasy is taken… 1. all of the serotonin in vesicle is released at once. This floods the synapse. 2. Then uptake serotonin receptors are blocked to that Serotonin remains in synapse. Now the NT can work longer on pleasure area of the brain.

39. Drug Types • Types • Psychoactive – alters mood or consciousness; affects neural functioning • Non-psychoactive – e.g., antibacterial • Classes of psychoactive drugs • Sedative-Hypnotics • E.g. Barbiturates, Anti-anxiety, alcohol • Reduce anxiety (low), sedation (medium), anesthesia (high) • Behavioral Stimulants and Consultants • E.g. Amphetamines, Cocaine, Caffeine, Nicotine • Increase activity (increase motor activity or counter fatigue)

40. Drug Types • Classes of psychoactive drugs • Narcotic Analgesics • E.g., Opium, heroine, morphine, codeine • Relieve Pain • Antipsychotic Agents • E.g., Lithium, haloperidol, reserpine • Used to treat schzophrenia • Psychedelics and Hallucinogens • E.g., LSD, Marijuana, MDMA (Ecstasy) • Alter sensory perception and cognitive processes

41. Drug Harm • Nutt et al. (2007) – The Lancet • Two sets of experts rate drugs on dimensions of harm • Physical Harm – acute, chronic, Intravenous • Dependence – pleasure intensity, psychological dependence, physical dependence • Social Harm – Intoxication, other social harm, health-care costs

42. What Kind of Drug is Nicotine? • At low doses it acts as a stimulant, at higher doses it acts as a sedative. • does not cause a high, but rather, modulates emotions. • Stimulates the amplified release of three neurotransmitters: dopamine, epinephrine and norepinephrine.

43. Psychoactive substances and their potential for producing dependence

44. Central Nervous System Stimulants (Uppers) • Another group of abused drugs. • Amphetamines: synthetic stimulants. • Effects: ALERT, less fatiqued or bored and INCREASED motor activity. • Increased heart rate and BP, decreased appetite. • Examples: Methadrine, Speed, Crack. Cocaine • Dependence: Tolerance is achieved even after moderate doses. Long-term users can suffer brain damage similar to Parkinson’s disease.

45. Stimulants • Effects: • heartbeat accelerates • blood pressure rises • blood vessels constrict • gastric & adrenal secretions increase • greater muscular tension • increased motor activity

46. Stimulant’s (continued) • Ritalin • Common treatment of ADHD and ADD. • Ephedrine • Found in Chinese herbal tea. • “Herbal ecstasy” • Common in weight loss and driver stimulant products. • Caffeine • The most commonly used psychoactive drug in US. • Coffee, tea, cocoa, soft drinks. • Does sugar cause psychological disorders?

47. Dependence on Stimulants • Repeated use of amphetamines leads to tolerance. • Psychosis is a possible consequence of a person of high doses; a temporary state of severe paranoia; with delusions of persecution and unprevoked violence. • Bottom Line: You can easily get hooked on uppers.

48. How Neurotransmitter Systems Work

49. How Different Drugs Exert Their Effect on Neurotransmitter System

50. CNS Depressants: • Slow nervous system down • alcohol • tranquilizers • barbiturates • Effects - • reduce anxiety • mood changes • slurring of speech • drowsiness, sleep • sedatives - hypnotics