THE BRAIN & DRUGS. Nebraska Training on Substance Abuse Prevention

Transcription

1 THE BRAIN & DRUGS Nebraska Training on Substance Abuse Prevention Educational Service Unit 10 Building 76 Plaza Blvd., Kearney, NE Tuesday, April 26th 2011 MODULE 2 1

2 Overview How does the brain work? How does the brain s reward system work? Drugs impact the brain and affect long-term functioning Addiction is a developmental disease 2

3 The Brain 3 3

4 Brain Communication Overview Brain is made up of a complex network of billions of nerve cells called neurons, as well as other kinds of cells. Whether awake or sleeping the brain is wake transmitting information across the nervous system highway Glucose the brains primary fuel Brain produces enough electrical energy to power a 40-watt bulb for 24 hours 4

5 Brain Communication Network Neurons Neurons in the brain and spinal cord are part of the nervous system and act as a body's "Command Central. Send information from the brain throughout the body from one neuron to the next until ultimately reaching the muscles of organs of the body. Neuron also store information as memory Neurons contain three important parts: Cell body: Directs all activities of the neuron Dendrites: Short fibers that receive messages from other neurons and relay those messages to the cell body Axon: Long single fiber that transmits messages to from the cell body to dendrites of other neurons Transmission 5 is amazingly fast and often compare the activity of neurons to the way electricity works.

6 Neurotransmission Electrical impulses flow in the direction of the terminal When the impulses reach the terminal Release neurotransmitters Neurotransmitter bind to their receptors New impulse is generated at the bottom of the cell This is how information travels from one neuron to neuron 6

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8 How the Brain Communicates The complex communication system within the brain can be disrupted by the chemicals in drugs 8

9 The Brain s Reward System The brain s reward system is a collection of neurons that release dopamine, resulting in pleasure Dopamine 9

10 Abuse & Addiction Circuits Inhibitory Control Memory / Learning Motivation / Drive Reward 10

11 Cerebrum Frontal Lob Frontal Lobe Functions: Behavior Abstract thought processes Problem solving Attention Creative thought Some emotion Intellect Reflection Judgment Initiative Inhibition Coordination of movements Generalized and mass movements Some eye movements Sense of smell Muscle movements Skilled movements Some motor skills Physical reaction Libido (sexual urges) Three Main Parts 11

12 Mesolimbic Dopaminergic Pathways

13 200 Food % of Basal Release Empty Box Feeding Dopamine Time (min) is a Powerful Reinforcer % of Basal Release Amphetamine hr Time After Amphetamine 13

14 Drugs Change the Brain When dopamine receptors are activated by drugs, that can re-set the threshold required for response to a higher level Decreased dopamine receptor function results in decreased sensitivity to non-drug related stimuli (including natural reinforcers) 14

15 Drugs Change the Brain Cingulate Gyrus: Inhibitory control Frontal Cortex: Planning Drive Responsibility Emotions Reward 15

16 Drugs Change the Brain Brain Control, Rewards, and Addiction The brain controls everything to include - Memory, feelings of pleasure, emotion & reward The reward system is a collection of neurons that release dopamine, resulting in pleasure. Science has linked dopamine to most drugs. Drugs activate the reward system causing the neurons to release large amounts of dopamine Overtime the sensation of pleasure is diminishes because brain damage occurs Serious consequences occur through prolonged drug use that can permitting change the brain making it difficult to experience other pleasures Scientific evidence proves drugs literally change the brain As if a switch goes off in the brain and at that point the abuser becomes an addict. Addiction unlike other brain diseases is a chronic relapsing of disease characterized 16 by compulsive, often uncontrollable, drug seeking and drug use in the face of negative consequences.

17 Drugs Change the Brain The drug becomes the main reinforcer and motivational drive Self-control is simultaneously turned off Compulsive drug-taking results 17

18 Stahl, Essential Psychopharmacology

19 Dopamine-Releasing Chemicals Alcohol & Sedative/Hypnotics Opiates/Opioids Cocaine Amphetamines Entactogens (MDMA) Entheogens/Hallucinogens Dissociants (PCP, Ketamine) Cannabinoids Inhalants Nicotine Caffeine Anabolic-Androgenic Steroids Kevin McCauley, M.D

20 Caffeine and the Brain Caffeine s effects are so strong that just thinking you are taking caffeine - even when you are not - will make your brain dopamine spike (placebo affect) 20

21 Nicotine and the Brain Nicotine is the perfect drug. It increases dopamine levels at the same time that it decreases inhibition 21

22 NEUROCHEMICAL and RELATED EFFECTS of NICOTINE N I C O T Dopamine Norepinephrine Acetylcholine Glutamate Serotonin β-endorphin GABA Pleasure, reward Arousal, appetite suppression Arousal, cognitive enhancement Learning, memory enhancement Mood modulation, appetite suppression Reduction of anxiety and tension Reduction of anxiety and tension I N E Benowitz. Nicotine & Tobacco Research 1999;1(suppl):S159 S163.

23 Alcohol and the Brain Reduced brain volume and fewer brain neurons in children with Fetal Alcohol Syndrome (FAS) Shrinking of brain and deficits in frontal lobes among adult heavy drinkers 23

24 Marijuana and the Brain 24

25 Cocaine and the Brain Frontal Cortex Healthy Control Cocaine Abuser 25

26 Meth and the Brain Excess dopamine between neurons causes them to fire more often, resulting in euphoria. 26

27 Decreased Brain Function: Methamphetamine Abuser Healthy Control Drug Abuser 27

28 Dopamine Receptors are Reduced in Addiction Cocaine Meth Alcohol Control Heroin 28 Addicted

29 Detoxification Normal ) Cocaine Abuser (10 days abstinent) Cocaine Abuser (100 days abstinent) 29

30 Detoxification Healthy Control Meth Abuser 1 month abstinence Meth Abuser 14 month abstinence Slide # 22 30

31 Drug Addiction: A Developmental Disease The prefrontal cortex is underdeveloped in adolescence Lack of impulse control Lack of inhibition 31

32 Drug Addiction: A Developmental Disease Dopamine is reduced in teens reward system because dopamine has migrated to help develop the prefrontal cortex 32

33 Drug Addiction: A Developmental Disease Moderate drinking impairs learning and memory far more in youth than adults Adolescents need only drink half as much as adults to suffer the same negative effects Adolescents become addicted to nicotine with much lower exposure than adults 33

34 Drug Addiction: A Developmental Disease Adolescence is a critical time for preventing drug use and addiction Delayed use reduces chances of substance use disorders 34

35 Drug Addiction Addiction is a brain disease characterized by compulsive, often uncontrollable, drug seeking and drug use in the face of negative consequences 35

36 Disease? Addiction to alcohol and other drugs is a terminal disease which should be viewed no differently than if an individual has cancer, heart disease, diabetes, or any other progressive medical disorder. Kevin McCauley, M.D 36

37 The Brain and Addiction 37

38 The Human Condition Drug abuse does not take place in a vacuum We are all subject to its influences beyond our control: Genetic propensities (Up to 1/3 of all people) Basic neurochemical makeup Psychological dispositions Social conditions Existential Angst (sense of meaninglessness in life) 38

39 Mapping Social Stressors No students in this area. Poor family support Drug availability Poverty Crime 39

40 In addiction, the drug hijacks the survival hierarchy and is so close to actual survival that it is indistinguishable from actual survival New #1: DRUG! 2. EAT! 3. KILL! 4. SEX! Kevin McCauley, M.D 40

41 In addiction: a line is crossed > NON-ADDICT (never used drugs) (experimented in past) (uses drugs) (abuses drugs) ADDICT DRUG = DRUG DRUG = SURVIVAL Kevin McCauley, M.D 41

42 The drug is equated with survival at the level of the unconscious (i.e. the drug IS survival) DRUG = SURVIVAL Midbrain (Unconscious) 42

43 Glutamate Most abundant neurochemical in the brain Critical in memory formation & consolidation ALL drugs of abuse and potentially addicting behaviors affect Glutamate which results in changes in the brain preserving drug memories Glutamate is the currency of motivation A major player in addition & relapse Kevin McCauley, M.D. 43

44 Stress A major player in addition & relapse Releases Corticotrophin Releasing Factor (CRF) CRF triggers survival in the midbrain Reinforces survival Kevin McCauley, M.D 44

45 We all face stress, yes...but we don t all: Face the same severity of stress Face the same pattern of stress Have the functioning coping mechanisms Come to the table with the same brain Kevin McCauley, M.D 45

46 2 different KINDS of stressors EU-STRESS Good stressors Resolved when the subject successfully acts on the environment Examples Studying for a test and getting an A Sport victories Art Helping others Can actually protect the subject from addition DYS-STRESS Bad stressors Nothing the subject tries to resolve the stressor works Examples Domestic violence Sudden illness Injury A death or grieving Particularly pernicious in the formation of addition Kevin McCauley, M.D. 46

47 The Dopamine surge causes the drug to be tagged as the new, #1 coping mechanism for all incoming stressors Kevin McCauley, M.D 47

48 The Two Tasks of Addiction Treatment: 1. To give the addict workable, credible tools to proactively manage stress and decrease craving 2. For each individual addict, find the thing which is more emotionally meaningful than the drug - and displace the drug with it Kevin McCauley, M.D

49 Relapse Three things that are know to evoke relapse in humans: Brief exposure to the drug itself (dopamine release) Exposure to drug cues (glutamate release) Stress (corticotrophin releasing factor) Example of all three Talking about drugs (cues - glutamate) with other newlysober addicts in treatment (stressed - CRF) while smoking (dopamine surge) Kevin McCauley, M.D. 49

50 The Importance of Prevention The good news is that drug abuse is a preventable behavior 50

51 Dopamine-Releasing Behaviors Kevin McCauley, M.D Food (Bulimia & Binge Eating) Sex Relationships Other People ( Codependency, Control) Gambling Cults Performance ( Work-aholism ) Collection/Accumulation ( Shop-aholism ) Rage/Violence Media/Entertainment

52 The Full Spectrum of Addiction Alcohol & Sedative/Hypnotics Opiates/Opioids Cocaine Amphetamines Entactogens (MDMA) Entheogens/Hallucinogens Dissociants (PCP, Ketamine) Cannabinoids Inhalants Nicotine Caffeine Anabolic-Androgenic Steroids Food (Bulimia & Binge Eating) Sex Relationships Other People ( Codependency, Control) Gambling Cults Performance ( Work-aholism ) Collection/Accumulation ( Shop-aholism ) Rage/Violence Media/Entertainment Kevin McCauley, M.D

53 Brain Communication Network Brain Control, Rewards, and Addiction The brain controls everything to include - Memory, feelings of pleasure, emotion & reward The reward system is a collection of neurons that release dopamine, resulting in pleasure. Science has linked dopamine to most drugs. Drugs activate the reward system causing the neurons to release large amounts of dopamine Overtime the sensation of pleasure is diminishes because brain damage occurs Serious consequences occur through prolonged drug use that can permitting change the brain making it difficult to experience other pleasures Scientific evidence proves drugs literally change the brain As if a switch goes off in the brain and at that point the abuser becomes an addict. Addiction unlike other brain diseases is a chronic relapsing of disease characterized by 53 compulsive, often uncontrollable, drug seeking and drug use in the face of negative consequences.

54 QUESTIONS ABOUT THE BRAIN AND DRUGS??? 54