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Drugs

Drugs. Psychoactivity and Dependence. Psychoactive Drug. A chemical substance that alters perceptions, mood, or behavior Three common psychoactive drugs: Caffeine Alcohol Nicotine Induce an altered state of consciousness. Common Properties of Addiction. Physical dependence Tolerance

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Drugs

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  1. Drugs

  2. Psychoactivity and Dependence

  3. Psychoactive Drug • A chemical substance that alters perceptions, mood, or behavior • Three common psychoactive drugs: • Caffeine • Alcohol • Nicotine • Induce an altered state of consciousness

  4. Common Properties of Addiction • Physical dependence • Tolerance • Withdrawal symptoms • Drug rebound effect

  5. Drug Abuse • Recurrent drug use that results in disruption of academic, social, or occupational functioning or in legal or psychological problems

  6. Dependence • A state of physiological and/or psychological need to take more of a substance after continued use. • Withdrawal follows if the drug is discontinued • Psychological dependence although the body does not physically crave the drug, the mind does.

  7. Tolerance • Reduced responsiveness to a drug, prompting the user to increase the dosage to achieve effects previously obtained by lower doses of the drug • The user experience neuroadaptation and thus requires more of the drug to get the effect.

  8. Tolerance

  9. Withdrawal • The discomfort and distress that follow when a person who is dependent on a drug discontinues the use of the drug • Withdrawal symptoms are usually the opposite of the drug’s effects – Drug Rebound Effect

  10. Why do people abuse drugs?Biopsychosocial Theory

  11. Drugs and Neurotransmission

  12. Neurotransmission • The process whereby neurons communicate with each other • Neurotransmission, especially in the brain and spinal cord, helps explain the effects of psychoactive drugs. • Psychoactive drugs interfere with normal neurotransmission.

  13. Neurotransmitters • Chemical messengers that cross synaptic gaps between neurons • When released by the sending neuron, neurotransmitters travel across the synapse and bind to receptor sites on the receiving neuron, setting up the next link in the chain of communication.

  14. Synapse • The junction between the tip of the sending neuron and the receptor sites on the receiving neuron • Call the synaptic gap or cleft

  15. Neural Activity

  16. Neurotransmitters and the Synapse

  17. Reuptake • Process where the unused neurotransmitter chemical is reabsorbed by the sending neuron

  18. Reuptake

  19. Psychoactive Drugs and Synapses • Psychoactive drugs affect synapses and neurotransmitters in three ways: • Binding with receptor sites (mimics)* • Blocking receptor site • Blocking neurotransmitters’ reuptake* * Increase the likelihood of the receiving neuron firing

  20. Drug Classifications

  21. Four Psychoactive Drug Categories • Four different categories we will study: • Depressants – depress, inhibit brain activity • Opiates – Similar to morphine, produce feelings of euphoria & reduce pain • Stimulants – excite brain activity • Psychedelic/Hallucinogens/Marijuana – distort sensory perceptions. • Designer “Club” Drugs – “fifth category” that includes variety of psychoactive drugs.

  22. Drug Classifications: Depressants

  23. Depressants • Drugs that reduce neural activity and slow body functioning • Includes alcohol and sedatives

  24. Types of Drugs: Depressants • class of substances that reduce central nervous system activity and slow bodily functions and awareness • alcohol • 40% of US adults report that they drink alcohol • 9% of US adults (14 million people) have alcohol abuse or dependence • has inhibitory effect on excitatory neurotransmitters • also on inhibitory neurotransmitters (disinhibition)

  25. Types of Drugs: Depressants • psychological effects of alcohol • reduction of inhibitory conflict (behavior that is both strongly instigated and inhibited) • facilitates aggressive behavior (alcohol myopia: disproportionate influence of immediate experience on behavior and emotion due to alcohol use)

  26. Types of Drugs: Depressants • barbituates: (aka. tranquilizers) drugs that mimic the effects of alcohol by depressing nervous system activity • cause sedation and drowsiness, often used as sleep aids • can be lethal alone or especially in combination with alcohol • opiates: opium and its derivatives (morphine, codeine, heroin) • can alleviate physical pain and anxiety, but highly addictive • activate dopamine-based reward pathway • bind to brain’s opioid receptors, leading body to produce less endorphins, leaving person craving more opiates to relieve pain

  27. Depressants • Alcohol—CNS depressant • Barbiturates—induce sleep • Tranquilizers—relieve anxiety

  28. Depressants/Sedatives • Reduce or depress CNS activity • Partly by increasing activity of the inhibitory neurotransmitter GABA. (GABA Agonist) • Examples • Alcohol • Barbiturates – very addictive • Gamma Hydroxybutryrate (GHB) Continue

  29. Alcohol (ethyl alcohol) • Found in beer, wine, and liquor • The second most used psychoactive drug (caffeine first) • Slows thinking, and impairs physical activity

  30. Blood Alcohol Content (BAC) • A measure of how much alcohol is in a person’s bloodstream • BAC of .08 considered legal intoxication in most states

  31. What do we mean by “one drink?” One 12-ounce can of beer has about the same amount of alcohol as 4 ounces of wine or 1 ounce of whiskey

  32. Euphoric Affects of Alcohol • Alcohol impairs the parts of the brain responsible for controlling inhibitions and making judgments • Results in less self-control and sometimes more aggressive behavior. • Also depends on environment and expectations.

  33. Effects of Alcohol • Affects Several Neurotransmitters • Dopamine • Seratonin • GABA • Enhances the Effect of Endorphins – (natural pain killers) • Interacts with Dopamine Systems (Permanent damage to ability to feel pleasure with prolonged abuse) • Affects Specific Brain Regions • Depresses activity in the locus coeruleus (activation center for cerebral cortex – judgment, inhibitions.) • Impairs the hippocampus (memory) • Suppresses the cerebellum (coordination) Return

  34. Alcohol, Memory, and Sleep • Studies have shown that alcohol impairs memory by suppressing the processing of events into long term memory. • Alcohol impairs REM sleep, further disrupting memory storage. • Also impairs speech and physical functioning. • Death can occur if the brain’s respiratory center can no longer function.

  35. Alcohol’s Affect on the Brain Alcoholism shrinks the brain

  36. Sedatives • Drugs that reduce anxiety or induce sleep • Also called tranquilizers • Include barbiturates and benzodiazepines

  37. Barbiturates • Drugs that depress the activity of the central nervous system and thereby reduce anxiety • Can be lethal in overdose and interact with other drugs, especially alcohol • Impair both memory and judgment • Can create tolerance and physical & mental dependence • Withdrawal can cause REM rebound nightmares, hallucinations, disorientation and even life-threatening convulsions.

  38. Benzodiazepines/Tranquilizers • Drugs that depress that activity of the central nervous system without most of the side effects associated with barbiturates • Help to reduce anxiety • Include Valium and Xanax • Can create dependency

  39. Inhalants • Chemicals that are inhaled to alter consciousness. • Paint, glue, gasoline, nitrous oxide & aerosol sprays. • Low doses may relax and reduce inhibition • High doses can cause hallucinations and loss of consciousness. • Toxic to the liver and other organs.

  40. Drug Classifications: Opiates

  41. Opiates/Narcotics • Drugs that depress neural activity, temporarily lessen pain and anxiety and produce feelings of euphoria • Include: opium, morphine, and heroin

  42. Opiates • Can induce sleep and relieve pain. • Depress activity in cerebral cortex • Agonist for endorphins • Have complex effects on consciousness. • Highly addictive class of drugs. • Severe physical withdrawal • High overdose incidence • Examples • Opium • Morphine • Heroin • OxyContin

  43. Endorphins • Natural, opiate-like neurotransmitters linked to pain control and to pleasure • Body’s natural pain killers

  44. Morphine • Strong sedative and pain-relieving drug derived from opium • Works by preventing pain neurons from firing or releasing pain-signaling neurotransmitters (Substance P) into the synapse

  45. Other Opiates Chemically similar to morphine and have strong pain-relieving properties • Mimic the brain’s endorphins • Heroin, methadone • Percodan, Demerol

  46. Drug Classifications: Stimulants

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