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?
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.
What are the different reasons people use drugs? At what point can we say that someone is addicted to drugs?
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
4 Categories of Drugs • CNS Depressants • CNS Stimulants • Hallucinogens • Opiates
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)
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)
Mescaline and Psilocybin http://www.elmhurst.edu/~chm/vchembook/672hallucin.html
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.
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.
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.
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.
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.
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.
What are the long term effects of drugs on the brain?
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.
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.