Drug AdministrationSlide 2Mechanisms of Drug ActionDrug MetabolismDrug ToleranceSlide 6Drug WithdrawalAddiction: What Is It?Learning in Tolerance and WithdrawalExample: Effects of AlcoholSlide 11Slide 12Slide 13Slide 14Results5 Commonly Abused DrugsTobaccoEffects of Long-Term Tobacco UseSmokingMushroomsAlcoholEffects of Chronic Alcohol ConsumptionOther damageMarijuanaSlide 25Medicinal Uses of MarijuanaTHCDiscussionStimulantsCocaineRisks of Cocaine SpreeAmphetamineFactors Increasing Opiate PopularityU.S. Opiate HistoryOpiate AddictionRisksTreatment for Heroin AddictionSlide 38Recommendations from ExpertsMoreTolerance is Life, Prohibition is DeathReducing Drug AbuseQuick ReviewSlide 44Slide 45Biopsychological Theories of AddictionCauses of RelapsePleasure Centers of the BrainDrug use may be reinforced by acting on this circuitryMesotelecephalic Dopamine (DA) System and Self-StimulationSlide 51Mesocorticolimbic Pathway and RewardSlide 53Behavioral preference testsDopamine and Drug AddictionDA and AddictionAddictionDrug Administration•Ingestion – oral route•Injection – bypasses digestive tract–Subcutaneously (SC) – under the skin–Intramuscularly (IM) – into large muscles–Intravenously (IV) – into veins1Drug Administration•Inhalation–Absorbed through capillaries in lungs•Absorption through mucous membranes2Mechanisms of Drug Action•Blood-brain barrier•Act diffusely on neural membranes•Bind to particular synaptic receptors3Drug Metabolism•Action of most drugs terminated by enzymes in the liver4Drug Tolerance•Decreased sensitivity to a drug as a consequence of exposure to it–Decrease in response–Increase in amount needed–Shift Dose-response curve5Drug Tolerance•Cross tolerance•Metabolic Tolerance•Functional Tolerance**6Drug Withdrawal•Usually opposite effect•Physically dependent7Addiction: What Is It?•“Addicts” are those who continue to use a drug despite its adverse consequences•Addiction vs. physical dependence8Learning in Tolerance and Withdrawal•Contingent drug tolerance•Tolerance only develops to drug effects that are experienced–Before and After Design9Example: Effects of Alcohol•Group 1: injection of alcohol 1 hour before mild convulsive stimulation –Anticonvulsant effect of alcohol experienced•Group 2: injection of alcohol 1 hour after mild convulsive stimulation–No anticonvulsant effect experienced1011Learning in Tolerance and Withdrawal•Conditioned drug tolerance–Maximal tolerance effects are seen in the environment in which a drug is usually taken•Group 1: alcohol injections in distinctive room, saline in colony room•Group 2: alcohol injections in colony room, saline in distinctive room1213Learning in Tolerance and Withdrawal•Group 1: morphine in distinctive environment, saline in home cages•Group 2: morphine in home cages, saline in distinctive environment•Group 3: saline injections in both distinctive and home cages (control)14Results•Rats that had received morphine in distinctive environment displayed substantially more withdrawal symptoms. 155 Commonly Abused Drugs•Tobacco•Alcohol•Marijuana•Cocaine •Opiates16Tobacco•Nicotine•70% who try it become addicted•20% quitting success rate17Effects of Long-Term Tobacco Use•Smoker’s syndrome•Susceptible to various lethal lung disorders – pneumonia, bronchitis, emphysema, lung cancer18Smoking•Morning vs. Later•Nicotine – Ach and Dopamine19Mushrooms•From Scandinavia and Russia•Muscarinic Receptors – Ach•Hallucinogenic Properties20Alcohol•A depressant•GABA, Dopamine, Serotonin•High heritability estimate for alcohol addiction - ~55%21Effects of Chronic Alcohol Consumption•Severe withdrawal – 3 phases–5-6 hrs post-drinking: tremors, nausea, sweating, vomiting, etc.–15-30 hrs: convulsive activity–24-48 hrs: delirium tremens – may last 3-4 days•Korsakoff’s syndrome•Cirrhosis – scarring of liver22Other damage•Increases chance of heart attacks•Oral and liver cancer•Stomach ulcers•Pancreatitis (inflammation of pancreas)•Gastritis (inflammation of stomach)•Drunk driving•Psychological effects of family and friends23Marijuana •Cannabis sativa – common hemp plant•Quick History•The mislabeled drug24Marijuana •STM and tasks involving multiple steps•Addiction potential is low•Respiratory problems•Elevated heart rate25Medicinal Uses of Marijuana•Treat nausea •Block seizures•Dilate bronchioles of asthmatics•Decrease severity of glaucoma•Reduce some forms of pain26THC•Fat-soluble•Binds to receptors in basal ganglia, hippocampus, cerebellum, and neocortex•Endogenous ligand is anandamide27DiscussionWhat is your opinion? Why are tobacco and alcohol legal and not marijuana (or vice versa)? 28Stimulants•Cocaine•Crack•Cocaine is an effective local anesthetic29Cocaine •Cocaine binges or sprees may lead to cocaine psychosis–Looks like paranoid schizophrenia•Although highly addictive, withdrawal is relatively minor30Risks of Cocaine Spree•Loss of consciousness•Seizures•Respiratory arrest•Heart attack•Stroke31Amphetamine•“Speed” – another abused stimulant•Effects are comparable to those of cocaine – also can produce psychosis•Methamphetamine (meth) and MDMA (ecstasy) – relatives of amphetamine•Evidence suggests that stimulants are neurotoxins32Factors Increasing Opiate Popularity•China’s ban of tobacco smoking led to opium smoking•Isolation of morphine •The hypodermic needle–“soldiers’ disease”33U.S. Opiate History•Readily available in a variety of “potions” until 1914•Harrison Narcotic Act (1914) •Heroin illegal as of 192434Opiate Addiction•Rush of injection•Risks: constipation, menstrual irregularity, reduced libido•Doctors and Nurses•Withdrawal–Restlessness, watering eyes, sweating, etc.–Chills, goosebumps, muscle spasms, etc.c–“Going cold turkey” “Kicking the habit”35Risks•Indirect•Battle between addictive power and its illegality•Greatly inflated prices•Poverty, petty crime, Undernourished, poor medical care, prostitution•Cut drugs, Overdose36Treatment for Heroin Addiction•Opiates bind to endorphin receptors•Methadone•Buprenorphine•Substituting a less dangerous drug for the abused drug3738Recommendations from Experts1. Support drug education, research and social programs2. Care for addicts3. Judges should be given greater discretion in sentencing4.