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Hani hamed dessoki biological addiction

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Hani hamed dessoki biological addiction

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  2. 2. Biological Considerations of Addiction Dr. Hani Hamed Dessoki, M.D.Psychiatry Prof. Psychiatry Chairman of Psychiatry Department Beni Suef University Supervisor of Psychiatry Department El-Fayoum University APA member
  3. 3. Objectives Definitions &Introduction  Multidimensional Model of addiction Contributing factors Neurobiology of addiction, tolerance & withdrawal Addiction in adolescents
  4. 4. Some definitions Drug abuse – use of hard drug in a manner or amount that is harmful or potentially harmful. Drug addiction – compulsive use of hard drug in the presence of harm (psychological, physical or social). Drug dependence – when one needs the drug to avoid withdrawal state or to maintain functional status
  5. 5. The Spectrum of Substance Use Disorders Dependence Syndrome Substance Abuse Harmful Use Hazardous Use moral Use Non-Hazardous Non-User/Abstainer
  6. 6.     
  7. 7. Addiction is a Complex Disease …with biological, sociologic al and psychological components
  8. 8. What IS addiction?       heroin addiction cocaine addiction alcohol addiction (“alcoholism”) marijuana addiction amphetamine addiction nicotine addiction
  9. 9. What IS addiction?       sex addiction?? gambling addiction?? food addiction?? shopping addiction???? internet addiction???? cell phone addiction????
  10. 10. Addiction Is Multidimensional Addiction is influenced by many factors including biological (neurobiology), social (family, friends, work) and personal (psychological processes relating to addiction). Thus while the potential for addiction is related to neurobiology in some degree, situational (social circumstances) factors play a substantial role. Indeed, many people use alcohol and drugs and do not become addicted.
  11. 11. The Development of Addiction: Genetics However, behaviors are complex genetic traits Environment Family, Friends Co-morbidity Work Gene/ Environment Interaction Genetics Specific Genes Genetics May Influence How Neurobiology Interacts With Environment
  12. 12. The disease model-Genetics Scientists will never find just one single addiction gene. Susceptibility to addiction is the result of many interacting genes
  13. 13. Why Do People Take Drugs in The First Place? To feel good To have novel: feelings sensations experiences AND to share them To feel better To lessen: anxiety worries fears depression hopelessness
  14. 14. Why Do People Abuse Drugs? Drugs of Abuse Engage Systems in the Motivation and Pleasure Pathways of the Brain
  15. 15. Drug abuse as a Biological Concept
  16. 16. The reward pathway
  17. 17. This system generates signals in a part of the brain called the ventral tegmental area (VTA) that result in the release of the chemical dopamine (DA) in another part of the brain, the nucleus accumbens (N-Ac) . This release of DA into the N-Ac causes feelings of pleasure. Other areas of the brain create a lasting record or memory that associates these good feelings with the circumstances and environment in which they occur.
  18. 18. Neurobiology/mechanism of drug addiction Three mechanisms at the synaptic junction of brain nerve cells • Neural – acute exposure • Cellular (regulation of ion channels and electrical properties) – long term exposure • Molecular mechanisms – long term exposure
  19. 19. AND… We Have Evidence That These Changes Can Be Both Structural and Functional
  20. 20. Addiction is a Brain Disease Prolonged Use Changes the Brain “Healthy” Brain “Cocaine Addict” Brain in Fundamental and Lasting Ways
  21. 21. Repetitive substance use: 1. Re-sets the reward system 2. Activates the brain’s stress systems 3. Impairs the pre-frontal inhibitory systems
  22. 22. movement motivation Dopamine addiction Reward & well-being
  23. 23. Natural Rewards Food Sex Excitement Comfort
  24. 24. Withdrawal: Brain Areas Frontal Cortex Thalamus Ventral Tegmental Area (VTA) Amygdala Locus Coeruleus The thalamus is activated when drugs of abuse are abruptly ceased LC has projections to frontal cortex, limbic cortex, and amygdala
  25. 25. Withdrawal: Corticotrophin Releasing Factor (CRF) Involvement The CRF system mediates the affective and somatic symptoms of drug withdrawal Koob, 2008, PNAS 105(26), 8809-10, Copyright 2008, National Academy of Sciences, U.S.A. Heart rate Blood pressure Blood glucose Response to stressors
  26. 26. Biological basis for drug tolerance (habituation) Biological systems strive for homeostasis When systems are highly active, the body responds by decreasing activity. Down-regulation is part of the biological basis for drug tolerance (habituation)
  27. 27. What is down-regulation Decrease in transmitter release (rapid) Decrease in receptor sensitivity (slower) Decrease in receptor sites (slower)
  28. 28. Double your pleasure, double your fun
  29. 29. The Development of Addiction: Adolescence Neuronal Development  The back of brain matures first… • sensory and physical activities favoured over complex, cognitive-demanding activities • propensity toward risky, impulsive behaviors  group setting may promote risk taking • poor planning and judgment
  30. 30. The Development of Addiction: Adolescence Neuronal Development: Grey matter maturation moves from back to front Gogtay et al (2004) PNAS, 101 (21). Copyright 2004, National Academy of Science, U.S.A.
  31. 31. The Development of Addiction: Adolescence This imbalance leads to... risk taking low effort - high excitement activities interest in novel stimuli PFC planned thinking impulsiveness Amygdala NAc
  32. 32. The Development of Addiction: Adolescence Add stress and alcohol/drug use... PFC Amygdala NAc
  33. 33. Take Home Message The classic anatomical areas of the brain involved in the reward pathway include the nucleus accumbens, ventral tegmental area and the prefrontal cortex.. Dopaminergic activity is the final chemical action in most behaviours relating to reward. The changes in addiction can be structural and functional.

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