THE ADDICTIVE BRAIN SC 212 JANUARY JOHN BUSH

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2 THE ADDICTIVE BRAIN SC 212 JANUARY JOHN BUSH

3 REVIEW OF DVD LECTURE FOUR GENETICS BORN TO BE AN ADDICT? Why do some people become addicts while others do not? Is there an addiction gene? Can specific genes associated with addiction be identified and located in a chromosome? Can the functions of genes associated with addiction be determined? Of what value might this information be?

4 REVIEW OF DVD LECTURE FIVE YOUR BRAIN ON DRUGS How do psychoactive drugs cause their psychological effects? What determines the strength of a drug s effects? How do we become dependent on drugs?

5 NEURONS & SYNAPSES

6 NEURAL MECHANISMS OF TOLERANCE AND WITHDRAWAL Receptor down regulation Receptor up regulation Allosteric modification

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8 SUMMARY OF LECTURE SIX: CAFFEINE An adenosine receptor antagonist that can affect the sleep-wake cycle Weakly stimulates the reward circuit Repeated use leads to mild physical dependence and craving negative reinforcement? Rate of metabolism is genetically determined Can contribute to dangerous behavior in combination with alcohol

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10 SUMMARY OF LECTURE SIX: NICOTINE Benefits performing tasks requiring attention and memory Agonist for a class of acetyl choline receptors in the VTA that triggers the release of high concentrations of dopamine Dopamine signals the need for new learning Strengthens neural pathways that lead to craving Results in abuse that is difficult to treat

11 TREATMENT OPTIONS Behavioral therapy Nicotine replacement therapy-vaping? Pharmaceutical therapy Bupropion (Welbutrin, Zyban) Varenicline (Chantix): behavioral changes Psilocybin??????

12 VARENICLINE

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14 DVD LECTURE SEVEN ALCOHOL SOCIAL LUBRICANT OR DRUG OF ABUSE?

15 BREAK

16 SUMMARY OF LECTURE SEVEN: ALCOHOL Alcohol is a psychoactive, potentially addictive drug of abuse Low doses of alcohol can be beneficial to health and in facilitating social interaction Chronic abuse is linked to adverse affects on individuals, society and the economy Alcohol abuse disorder is a polygenic trait Treatments for alcoholism are marginally effective

17 WASHINGTON POST DECEMBER 23, 2016

18 REVIEW: EFFECTS OF ALCOHOL ON THE BRAIN Alcohol binds to several types of receptors in the brain Dopamine receptors Glutamate-NMDA receptors GABA receptors Barbiturates Repeated use leads to changes in the brain Upregulation of NMDA receptors Downregulation of GABA receptors Abnormal dendrites in the pre frontal cortex Induction of Δ FOS B Destruction of limbic system neurons

19 TREATMENT OPTIONS Detoxification-naltrexone, acamprosate, benzodiazepines (Valium, Xanax) Psychosocial rehabilitation Pharmacological interventions Benzodiazepines amplify GABA s inhibitory effects Naltrexone blocks opioid receptors and reduces the pleasure of drinking Acamprosate reduces NMDA s response to glutamate Disulfiram combined with alcohol causes unpleasant sensations Pharmaceutical cures seem unlikely

20 A CONTROVERSY: SHOULD ALCOHOLISM BE CALLED A DISEASE? Are alcoholism, alcohol dependence and alcohol abuse the same? Proponents-many medical associations, NIAAA, many academic researchers for them the clinching evidence is the formation of ΔFOS B in the Nac Opponents The disease concept gives alcohol abusers an excuse that eliminates free will and individual responsibility A majority of American doctors believed alcoholism is a social or psychological problem

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22 DVD LECTURE EIGHT THE SCIENCE OF MARIJUANA

23 MARIJUANA Marijuana (THC) is a psychoactive, addictive drug of abuse Endocannabinoid CB1 receptors are associated with psychoactive effects, especially forgetting, as well as with nausea and appetite How dangerous is marijuana (cannabinoids)? Does marijuana have medical benefits?

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25 CANNABINOIDS Compounds that interact with the CB1 or CB2 receptors Natural endocannabinoids-anandamide Natural exocannabinoids-113 in marijuana Psychoactive Δ-9 Tetrahydrocannabinol (THC) Not psychoactive Cannabidiol (CBD) Synthetic psychoactive cannabinoids (Spice, Bath Salts)

26 CANNABINOIDS CONFIRMED THERAPEUTIC BENEFITS Decrease chemotherapy-induced nausea CE Relieve chronic pain SE Reduce multiple sclerosis induced spasticity SE Increase appetite with HIV/AIDS LE Tourette syndrome LE Reduce damage from traumatic brain injury LE Treat addiction NE CE Conclusive evidence SE Substantial evidence LE Limited evidence NE No evidence

27 ADVERSE EFFECTS Cancer No documented risk Heart attack, stroke, diabetes Unclear Chronic cough Definite COPD, asthma Unclear Immune system Unclear Motor vehicle accidents Definite Impaired cognitive performance Definite Schizophrenia, suicidal thoughts(heavy users) Definite Problem cannabis use Definite Increased risk of abuse of other substances No documented risk

28 PSYCHOLOGICAL EFFECTS OF MARIJUANA Enhances activity in reward circuit Stimulates firing of dopamine neurons in the VTA--craving Anandamide produces pleasurable reactions in animals Quitting induces psychological withdrawal symptoms

29 CANNABIS USE DISORDER (CUD) Definition of the onset of CUD is not agreed 2001 survey: Addiction probability 9.9 % 2015 survey: 23.2 million users and 4.2 million reported with CUD symptoms (18.9%) Risk factors for CUD Youth Frequent, heavy user of marijuana Male cigarette smoker Subject to major depressive disorder

30 IS MARIJUANA ADDICTIVE? Everybody thinks getting high is cool, you can let it go when you want to let it go. But it s just as potent as alcohol. It s just as potent as cocaine. Rashaan Salaam

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