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NIDA. NATIONAL INSTITUTE ON DRUG ABUSE. Drug Abuse & Addiction. Bringing the Full Power of Science to Bear on. Addiction. Medical. Medical. Neurotoxicity AIDS, Cancer Mental illness. NEUROTOXICITY AIDS CANCER MENTAL ILLNESS. DRUGS. Economic. Social. Health care Productivity
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NIDA NATIONAL INSTITUTE ON DRUG ABUSE Drug Abuse & Addiction Bringing the Full Power of Science to Bear on
Addiction Medical Medical Neurotoxicity AIDS, Cancer Mental illness NEUROTOXICITY AIDS CANCERMENTAL ILLNESS DRUGS Economic Social Health care Productivity Accidents Homelessness Crime Violence
Estimated Economic Cost to Society from Substance Abuse and Addiction: Illegal drugs: $181 billion/year Alcohol: $185 billion/year Tobacco: $158 billion/year Total: $524 billion/year Surgeon General’s Report, 2004; ONDCP, 2004; Harwood, 2000.
What is Addiction?Addiction is A Brain Disease • Characterized by compulsive behavior • The continued abuse of drugs despite negative consequences • A chronic, potentially relapsing disorder
Advances in science have revolutionized our fundamental views of drug abuse and addiction.
1-2 Min 3-4 5-6 6-7 7-8 8-9 9-10 10-20 20-30 Your Brain on Drugs Today YELLOW shows places in brain where cocaine binds (striatum) Front of Brain Back of Brain Fowler et al., Synapse, 1989.
High Low • Addiction is Like Other Diseases… • It is preventable. • It is treatable • It changes biology. • If untreated, it can last a lifetime. Decreased Heart Metabolism inHeart Disease Patient Decreased Brain Metabolism inDrug Abuser Healthy Brain Diseased Brain/ Cocaine Abuser Diseased Heart Healthy Heart Research supported by NIDA addresses all of these components of addiction
Addiction Is A Developmental Disease that starts in adolescence and childhood 1.8% 1.8% TOBACCO CANNABIS 1.6% 1.6% ALCOHOL 1.4% 1.4% 1.2% 1.2% 1.0% 1.0% % in each age group who develop first-time dependence 0.8% 0.8% 0.6% 0.6% first 0.4% 0.4% 0.2% 0.2% 0.0% 0.0% 5 10 15 21 25 30 35 40 45 50 55 60 65 5 10 15 21 25 30 35 40 45 50 55 60 65 Age Age Age at tobacco , alcohol and cannabis dependence per DSM IV National Epidemiologic Survey on Alcohol and Related Conditions , 2003. National Epidemiologic Survey on Alcohol and Related Conditions , 2003.
Why Do People Take Drugs in The First Place? To feel better To lessen: anxiety worries fears depression hopelessness To feel good To have novel: feelings sensations experiences AND to share them
Why Do People Abuse Drugs? Drugs of Abuse Engage Systems in the Motivationand Pleasure Pathways of the Brain
Dopamine motivation Reward& well-being addiction movement
Dendrites Axon Cell body (the cell’s life Terminal support center) branches of axon Neuronal Impulse Myelin sheath The Neuron: How the Brain’s Messaging System Works Donald Bliss, MAPB, Medical Illustration
dopamine transporters
15 10 Copulation Frequency 5 0 Mounts 1 2 3 4 5 6 7 8 Intromissions Ejaculations Natural Rewards Elevate Dopamine Levels SEX FOOD 200 200 NAc shell 150 150 DA Concentration (% Baseline) 100 100 % of Basal DA Output Empty 50 Box Feeding 0 0 60 120 180 Female Present Time (min) Sample Number Di Chiara et al., Neuroscience, 1999. Fiorino and Phillips, J. Neuroscience, 1997.
Effects of Drugs on Dopamine Release COCAINE AMPHETAMINE Accumbens 1100 Accumbens 400 1000 900 DA 800 DA 300 DOPAC 700 DOPAC HVA % of Basal Release HVA 600 % of Basal Release 500 200 400 300 100 200 100 0 0 0 1 2 3 4 5 hr Time After Amphetamine Time After Cocaine NICOTINE MORPHINE 250 Accumbens 250 Dose (mg/kg) 200 Accumbens 0.5 200 Caudate 1.0 2.5 150 % of Basal Release 10 150 % of Basal Release 100 0 1 2 3 hr 100 0 1 2 3 4 5 hr 0 0 0 1 2 3 4 5hr Time After Nicotine Time After Morphine Di Chiara and Imperato, PNAS, 1988
But Dopamine is only Part of the Story Other neurotransmitter systems are also affected: • Serotonin: mood regulation, sleep • Glutamate: learning and memory
Science Has Generated Much Evidence Showing That… Prolonged Drug Use Changes the Brain In Fundamental and Long-Lasting Ways
AND… We Have Evidence That These Changes Can Be Both Structuraland Functional
Structurally… NAC Amph Saline Source: Robinson & Kolb, Journal of Neuroscience, Volume: 1997
Functionally… Dopamine D2 Receptors are Lower in Addiction Cocaine DA DA DA DA DA DA DA DA DA DA DA DA Meth Reward Circuits DA D2 Receptor Availability Non-Drug Abuser DA DA Alcohol DA DA DA DA Heroin Reward Circuits Drug Abuser Control Addicted
2.0 1.8 1.6 1.4 1.2 Dopamine Transporter Time Gait Bmax/Kd 1.0 7 8 9 10 11 12 13 (seconds) 2.0 1.8 1.6 1.4 1.2 Delayed Recall (words remembered) 1.0 16 14 12 10 8 6 4 Dopamine Transporters in Methamphetamine Abusers Motor Task Loss of dopamine transporters in the meth abusers may result in slowing of motor reactions. Normal Control Memory task Loss of dopamine transporters in the meth abusers may result in memory impairment. Volkow et al., Am. J. Psychiatry, 2001. Methamphetamine Abuser
Implication: Brain changes resulting from prolonged use of drugs may compromise mental and motor functions
Circuits Involved In Drug Abuse and Addiction All of these must be considered in developing strategies to effectively treat addiction