Drugs & their effects on the CNS

1. Drugs & their effects on the CNS

2. Pre-class Brainstorm • What is the definition of a drug? • What are the different reasons people use drugs? • At what point can we say that someone is addicted to drugs? • What are some different categories of drugs? • What are some of the long term effects of drugs on the brain?

3. What is the definition of a drug?

4. Drug Definition • Any substance that alters mental functioning and whose use can lead to abuse or dependence. • Such substances are also known as psychoactive substances or psychotropics.

5. What are the different reasons people use drugs? At what point can we say that someone is addicted to drugs?

6. 3 Types of Substance Using Behaviour • Recreational use: using drugs in a way that does not lead to any health complications or behavioural problems • Substance abuse: using drugs in a way that may cause physical, emotional, psychological, or social harm to users or those around them • Substance dependence: can be sudden or gradual, when someone can no longer stop using a substance without experiencing physical or psychological suffering 2 types: physical and/or psychological

7. What are some different categories of drugs?

8. 4 Categories of Drugs • CNS Depressants • CNS Stimulants • Hallucinogens • Opiates

9. CNS Stimulants and Depressants • CENTRAL NERVOUS SYSTEM STIMULANTS • Stimulates neurons (causes increase in electrical activity) • Caffeine • Ecstasy • Cocaine • Nicotine • CENTRAL NERVOUS SYSTEM DEPRESSANTS • Depresses neurons (causes decrease in electrical activity) • Alcohol • Xanax® and Valium®  for people with anxiety • Narcotics (opium, morphine, codeine, heroin)

10. HALLUCINOGENS • Hallucinogenic compounds found in some plants and mushrooms (or their extracts) have been used—mostly during religious rituals—for centuries. • Many hallucinogens have chemical structures similar to those of natural neurotransmitters • The most widely used hallucinogens in North America are LSD (“acid”) and Psilocybin (“magic mushrooms”), PCP and Peyote (mescaline)

11. LSD http://www.elmhurst.edu/~chm/vchembook/672hallucin.html

12. Mescaline and Psilocybin http://www.elmhurst.edu/~chm/vchembook/672hallucin.html

13. Hallucinogens • LSD, peyote, psilocybin, and PCP are drugs that cause hallucinations, which are profound distortions in a person’s perception of reality. • Under the influence of hallucinogens, people see images, hear sounds, and feel sensations that seem real but are not.

14. Opiates • Opiates are drugs that come from the sap of the opium poppy, a flower native to Europe and East Asia. • Natural opiates are morphine, heroin and codeine. • Some synthetic (man-made) drugs mimic the effects of opiates, including Demerol and methadone. • All opiates are analgesics, or painkillers, and all are addictive.

16. Marijuana and the Brain • The active ingredient in marijuana that causes it’s effects is called THC (Tetrahydrocannabinol) • THC produces euphoria and a mild disorientation. Physical sensations seem more vivid, and perception of time may be distorted.

17. Marijuana- How it works. • Cannabinoid receptors are activated by a neurotransmitter called anandamide. • Anandamidebelongs to a group of chemicals called cannabinoids. THC is also a cannabinoid chemical. • THC mimics the actions of anandamide, meaning that THC binds with cannabinoid receptors and activates neurons, which causes adverse effects on the mind and body.

18. THC

20. Marijuana and the Brain • THC affects three key brain functions: • Memory. • THC disrupts short-term memory and increases distractibility • Motor skills. • Marijuana can slow reaction time and reduce "tracking ability," which could mean serious problems for inexperienced teen drivers. • Thought. • Higher-order thinking skills are also affected, including calculation skills and the ability to follow complex instructions.

21. Marijuana- Long Term Effects Long-term risks of marijuana include: • Heart/Lungs • Marijuana raises heart rateand poses a risk to people with heart problems or hypertension. • Marijuana smoke irritates lung tissue and reduces respiratory capacity • Hormones • Marijuana lowers levels of sex hormones in both sexes. In children, such changes could affect sexual maturation and physical development. • Brain • Research shows that marijuana can interfere with the process by which short-term memories are encoded and stored in the brain.

22. What are the long term effects of drugs on the brain?

23. Drugs and the Brain • A drug “high” lasts a short time, ranging from less than an hour to 12 hours, depending on the drug and dose. • The changes in the brain that result from continued drug use, however, can last a long time. • Some changes may disappear within a short time after drug use stops, while other changes may bepermanent.

24. Drugsand the Brain • The bottom line: drugs kill brain cells! • Unlike other types of cells in the body, neurons in many parts of the brain have little capacity to regenerate. • Alcohol, meth and MDMA have been shown to kill neurons in the part of the brain that helps create new memories (hippocampus). When these neurons die, the capability for learning decreases.