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This article explores the percentage probability of becoming addicted to alcohol based on the age at which an individual started drinking. It also examines the brain regions and functions related to pleasure and reward, as well as the impact of neurotransmission and drugs of abuse on the brain. The article highlights the vulnerability of the developing adolescent brain to addictive drugs and emphasizes the importance of prevention.
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Percentage Probability of Becoming Addicted to Alcohol Based on When the Individual Started Drinking Age Began Drinking Source: Hingson, R.W. , Heeren T., and Winter, M.R., “Age of Drinking Onset and Alcohol Dependence,” Archives of Pediatrics and Adolescent Medicine,” 2006.
Brain Regions and Functions PLEASURE/REWARD
The Frontal Lobes • Executive Functions • Abstraction • Sequencing • Prioritization • Planning • Judgment • Frontalization from Amygdala of Identifying Emotion
Neurotransmission Axon
Chemical Neurotransmission in the Brain’s Pleasure Circuit Axon of transmitting Nerve Cell Dendrite of receiver Nerve Cell
Pleasure Regulation Axon of transmitting Nerve Cell seratonin seratonin receptor Dendrite of receiver Nerve Cell
Dopamine drugs Heroin, Oxycontin, Vicodin, mimic dopamine Alcohol causes excessive dopamine release Nicotine prevents dopamine breakdown Serotonin Drugs Amphetamines, Ecstasy cause excessive serotonin release Cocaine prevents Serotonin Re-uptake (incidentally so do anti-depressants such as Zoloft, Paxol, etc.) Drugs of Abuse Increase BrainDopamine and/or Serotonin
RESPONSE #1 • Brain builds more receptors to catch excess dopamine/serotonin = serotonin
THE BRAIN RESPONDS BRAIN BLOCKS OFF AVAILABLE RECEPTORS IN SELF DEFENSE
Pleasure Regulation Axon of transmitting Nerve Cell seratonin seratonin receptor Dendrite of receiver Nerve Cell
Dr. Andrew Weil (M.D.) The Pleasure of Altering Consciousness "the desire to alter consciousness periodically is an (instinctive), normal drive…." with drugs only being one of many ways to satisfy this need. ~ The Natural Mind: From Chocolate to Morphine
Dr. Weil’s Definition of a Bad Relationship with a Drug • Ignorance of what the drug does to your body • Loss of the desired effect despite increasing frequency of use • Difficulty separating from the drug • Impairment of health or impairment of social functioning
amphetamines ecstasy LSD
PET Scans (Positron Emission Tomography) Color reflects metabolic activity in the brain RED is hot BLUE is not
Immediate effects of Cocaine in the brain Cocaine acutely activates the brain Scan from Brookhaven NLCIN
CHRONICALLY (long term) Cocaine reduces brain activity Normal Brain User’s Brain Scans from Brookhaven NLCIN
Drugs are so cool... Normal resting brain activity Cocaine abuser’s resting brain activity ...they freeze the brain Scans from Brookhaven NLCIN
Long term marijuana use produces changes in the brain Normal resting brain activity Marijuana user’s resting brain activity Scans from Brookhaven NLCIN
Serotonin Activity Shuts Down in Ecstasy Users Non-user’s brain Ecstasy user’s brain From The National Institute for Drug Abuse Prevention
Addiction is the creation of a negative state Initially the drug is used to feel high... ...over time, the drug is necessary to just feel normal (bring brain activity to normal levels)
The developing brain is more vulnerable to addictive drugs CEREBRAL BLOOD FLOW ANNUAL INCREMENTS 3-4 150 5-6 15-17 12-14 8-9 Ml/min - 150 2 4 6 8 10 12 14 16 18 AGE (years) Increased blood flow precedes the brain’s growth spurts Brain and Development 1999;21:535
THE PREFRONTAL CORTEX AND HIPPOCAMPUS GROW FASTEST IN ADOLESCENCE PREFRONTAL CORTEX reason, judgement PLEASURE/REWARD HIPPOCAMPUS memory
Frontal Lobe Brain Dysfunction in a Young Drinker Back of head Front of head 20 yr. old nondrinker 20 yr. old regular drinker Alcoholism: Clinical and Experimental Research, 2001;25:236
Alcohol Shrinks the Brain Normal (control) Alcoholic From The National Institute for Alcohol and Alcoholism Research
Hippocampal Volume Shrinks with Adolescent Alcohol Use Non-drinking adolescent Adolescent binge drinker American Journal of Psychiatry, 2000;157:737
“New research indicates that teenagers who drink too much may lose as much as 10% of their brainpower-” What does that 10% mean to you? Discover, Vol 22, March 2001
GROWING BRAINS ARE PARTICULARLY VULNERABLE • The brain keeps growing, developing new neurons, and setting up • circuits into the 20’s • Substance abuse in adolescence is more likely to lead to addiction • 1 in 3 adolescents who smoke, • 1 in 4 adolescents who drink, • 1 in 5 adolescents who use marijuana… • … will become dependent on the drug • Even if one escapes addiction, drugs put the brain at risk for • chronic changes that can affect function • Drug-induced brain damage is cumulative and may not be reversible
The media notoriously paints only half the picture of substance abuse Scene from Dawson’s Creek
Do the Math Media glorification/advertisement + Immediate consequences rarely seem severe + Pressures to use + Denial psychology/cognitive dissonance _____________________________________ = Easier to use than not to use?
This is your brain This is your brain on drugs NIDA Drug Prevention Campaign
Neurotoxic Effects of Stimulant Addictive Drugs Nicotine, Cocaine, Ecstasy, Amphetamines UCLA Brain Research Institute Neuropharmacology 2000;39:2792