Chemical Dependency, Neurobiology, and Addiction 1 Light University Online Chemical Dependency, Neurobiology, and Addiction ARCO 502 Module 1
Chemical Dependency, Neurobiology, and Addiction 1
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Chemical Dependency, Neurobiology, and Addiction
ARCO 502
Module 1
Chemical Dependency, Neurobiology, and Addiction 2
Light University Online
Module One
Table of Contents
Biological Aspects of Chemical Dependency & Addiction Michael Lyles, M.D. ....................................................................................................................................................... 3
CHEMICAL ADDICTION & ITS BIOLOGICAL ASPECTS
Chemical Dependency, Neurobiology, and Addiction 3
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Description Dr. Michael Lyles describes the neurological factors and processes that occur in the brain during addiction and chemical dependency. He describes the complications of substance abuse and the protective variables that deter drug use and eventual addiction. Dr. Lyles also provides extensive attention to the actual biological and physiological responses to various substances.
Learning Objectives:
1. Describe the neurological complications associated with substance abuse.
2. Explain the relationship between substances of abuse and the reward
system in the brain.
3. Identify the functions of the key parts of the brain in relation to each element’s role in addiction.
Biological Aspects of Chemical Dependency & Addiction
VIDEO
Michael Lyle, M.D.
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I. Prevalence of Addiction in America
A. 12.7 Million People have used an Illegal Drug in the Past Month B. 10 Million are Casual Users
C. 2.7 Million are Addicts D. 30-40 Million People in the Past Year E. “For I know that in me (that is my flesh) nothing good dwells; for to will is
present with me, but how to perform what is good I do not find. For the good that I will to do, I do not do; but the evil I will not to do, that I practice.”
Romans 7:18-19
F. “For I delight in the law of God according to the inward man. But I see another law in my members, warring against the law of my mind, and bringing me into captivity the law of sin which is in my members.”
Romans 7:22-23
G. “O Wretched man that I am! Who will deliver me from this body of death?” Romans 7:24
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II. Why Do People Use Drugs?
A. To Feel Good
B. To Self-Medicate/Numb Feelings
C. To Perform Better
D. To Fit In
E. Curiosity
III. Risk Factors for Drug Abuse
A. Genetics (40-60% of Vulnerability)
B. Family Relationships
C. Drug using Peers or Friends
D. Environmental Stress
E. Poor Social Skills
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F. Poor Spiritual “Skills”
G. Early Use
H. Method of Delivery
I. Past Experiences with Drug Use
IV. Protective Variables
A. Impulse Control & Self-Discipline
B. Positive Family Relationships
C. Supportive Parental Supervision
D. Positive Self-Esteem
E. Positive Peers
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F. Values (Biblical Input)
G. Internalized Spiritual Relationship with God
V. Complications of Drug Abuse
A. Relapse/Overdose
B. Depression/Suicide
C. Increase in Cancer Rates
D. IV Drugs Hepatitis, Thrombophlebitis, Respiratory Infections/Blood Clots, Bacterial Endocarditis, HIV Infection
E. Stroke, Heart Attacks
F. Legal, Relational, Financial, Vocational Difficulties
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G. Spiritual Separation Behold, the Lord’s hand is not shortened, that it cannot save; nor his ear heavy,
that it cannot hear. But your iniquities have separated you from your God; and your sins have hidden His face from you, so that He will not hear.
Isaiah 59:1-2
VII. Terminology
A. Addiction – A compulsive or obsessive drug usage with increased risk for relapse after stopping.
B. Tolerance – Reduced effect of a drug following repeated usage. C. Withdrawal – Either psychological or physiological reactions occurring when
the drug is stopped or reduced.
D. Cross-Tolerance/Dependency – The ability of one drug to suppress the withdrawal effects of another drug.
E. Reinforcement – The ability of the drug to promote repeated self-administration due to the feelings of pleasure one gets from taking the drug.
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F. Relapse – The recurrence of the original symptoms after effective treatment has been suspended.
G. Substance Abuse (DSM IV) – Maladaptive Pattern of Drug Use within 12 Month Period with Three of the Following:
Failure to fulfill responsibilities
Using when physically dangerous
Legal problems related to use
Persistent social or interpersonal problems
Tolerance
Withdrawal
Increasing amounts used or longer periods of time than planned
Desire or efforts to reduce or stop use
Increased time spent obtaining, using or recovering from the drug
Activities of life given up or reduced
Continued despite knowledge of consequences
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VII. Biology of the Brain and Addiction
A. Brain Terminology Neurotransmitters (6)
Serotonin
Dopamine
Endorphins
Norepinephrine
GABA
Synaptic Clefts (5)
Post-synaptic receptors (7)
Neuroplasticity: The system can change over time in response to drugs or stress
B. Pleasure/Reward System
Ventral Tegmental Area Nucleus Accumbens
Amygdala
Hippocampus
Locus Ceruleus
Medial Fascicular Bundle
Prefrontal Cortex
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C. Ventral Tegmental Area Top of the brainstem
Center of the brain dopamine system
Also influenced by endorphins (opiate type)
Pleasurable activities stimulate the VTA to make dopamine in mild to moderate
amounts that the brain can handle (35 60 mph)
The dopamine is shipped to the nucleus accumbens via the medial fascicular bundle
D. Nucleus Accumbens (The Ventral Striatum)
Center of pleasure and reward: Natural highs felt when 35 60mph Drugs of Abuse highjack the system and speed up the Nucleus Accumbens to 100
mph
Stimulates the Nucleus Accumbens excessively (excitotoxicity) and causes “neuroplastic” changes with repeated exposures
Serotonin/GABA (inhibition/braking) are decreased
All accelerator with no brakes/steering
E. Hippocampus
Located in the temporal lobes Have two of them
Foundation of memory formation
The details and context of the memories
Works hand in hand with the amygdala
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F. Amygdala
Center of emotional memory/learning Located in the temporal lobes
Involved in fear and pleasure
Imparts emotional “coloring” to memories, perceptions and behaviors
This “coloring” helps to “consolidate” memories and make them permanent
Reinforcement -- “It’s cool to go 100 mph; let’s do that again!”
G. Locus Ceruleus
Located in the brainstem Alarm center that goes off in response to stress and panic
Norepinephrine rich
Interacts with the entire brain/spinal cord
Acts like a spoiled child if it does not get its way – can generate a huge “fit” and
send 911 calls all over the body (part of the fight or flight response)
Reinforcement -- “It’s cool to go 100 mph; let’s do that again!”
H. Prefrontal Cortex
Center of executive functions Planning, motivation, decision-making, goals, consequences of actions, values
Connects to the VTA, nucleus accumbens
Tells it to stop it, this is not good
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I. Normal Reward System
Pleasurable activity stimulates the VTA which stimulates the nucleus accumbens, which says this is great.
The amygdala and hippocampus remember what made this so great, so that we
can do it again later. The greater the pleasure, the stronger the memory.
The frontal lobe says enough is enough, you need to stop and resume the rest of your life.
J. Reward System with Drug-Mediated Pleasure
The VTA, nucleus accumbens, amygdala, and hippocampus are “stimulated to death” very quickly and for a brief period of time. With repeated exposures, the system loses its calibration and thinks the dopamine high is normal acquired drive.
The system really likes (thinks it needs) this and wants more now! If dopamine
fix is not given, the locus ceruleus goes crazy and calls 911 on everybody craving.
Serotonin and GABA are turned off and impulse controls are lost.
The frontal lobe tries to tell it to stop but the system is on autopilot. If the craving is strong enough, it will not stop until the drug is obtained.
This is what addiction looks like: The frontal lobe has lost control and the inmates are running the show.
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K. Drugs of Abuse and Reward System
Nucleus accumbens directly stimulated by cocaine, amphetamines, opiates, and marijuana
VTA directly stimulated by alcohol, opiates, and nicotine
Locus ceruleus stimulated by nicotine, opiates, and alcohol
Hippocampus affected by nicotine, marijuana, and alcohol
L. Inmate Brain’s Natural “Pharmacy”
Endorphins (morphine, heroin, opioids) Anandamide (marijuana)
Acetylcholine (nicotine)
Dopamine (cocaine, amphetamines)
GABA (valium, xanax)
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VIII. Addiction as a Brain Disease
A. Drugs of abuse mimic naturally occurring substances of the brain
B. Highjacks the systems and changes the hardwiring of the brain (neuroplasticity)
C. Creates “acquired drives” that fool the brain into thinking that drugs are needed like food, air and water compulsive craving/drug seeking
D. Negatively affects areas critical to judgment, decision-making, learning, and memory
E. Some of these changes can be permanent
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Study Questions
1. According to Dr. Lyles, why do people use drugs?
2. Describe the primary risk factors for drug abuse.
3. Describe the complications of drug abuse.
4. Describe the neurological process of rewards and the difficulties in the system that occur following the introduction of substances of abuse.
5. Why does Dr. Lyles consider addiction to be a brain disease?