Lecture 4: Psychoactive Drugs 2024 PDF

CONSCIOUSNESS PSY1005S Lecture 4: Psychoactive Drugs 2024 Dependence Mechanisms & Categories of Drugs Alexa Soule [email protected] om...

CONSCIOUSNESS PSY1005S Lecture 4: Psychoactive Drugs 2024 Dependence Mechanisms & Categories of Drugs Alexa Soule [email protected] om Room 2.18, Psychology Department University of Cape Town  Outline of Lectures 1. Consciousness & Sleep 2. Sleep Disorders 3. Psychoactive Drugs: Definitions & Aetiology 4. Psychoactive Drugs: Dependence Mechanisms 5. Psychoactive Drugs: Specific Drugs  Family influences Factors that Social and environment Biological predispositio affect/ increase al factors ns risk of Aetiology substance use of SUDs initiation and maintenance Socioecono mic factors Psychologica l factors Cultural factors Not one factor causes SUD, but rather a combination of factors Personality traits: E.g., Novelty/sensation-seeking; impulsivity Poor psychosocial skills Psychologic al Factors Low self-esteem Mental disorders and psychiatric problems E.g., depression; PTSD; conduct disorder E.g., emotion regulation difficulties  Cultural Factors o Historical context E.g., dop system from Apartheid o Cross-cultural variations Different attitudes and practices E.g., use of ayahuasca in some indigenous South American tribes o Symbolism & meaning May be used symbolically or in rituals Socioeconomic Factors Unemployment Criminal behaviour Low educational attainment High rates of trauma and violence Socioeconomic disparities, societal inequalities & discrimination  Social & Environmental Factors Accessibility & Peer influence Media Social Availability exposure pressure Peer pressure to use Media Easy access and Social norms, substances, representations availability of traditions or rituals especially during glamorizing or substances in one's encouraging adolescence. normalizing environment. substance use. substance use.  Understand Differentiate the roles of Identify key between withdrawal, mechanisms physical and classical that psychological conditioning, contribute dependence tolerance, to on Learning psychoactive psychoactiv and dopaminergi e drug Outcome drugs. dependence c pathways in addiction. sLecture 4 Describe the long- Describe the effects term consequences of different types of of psychoactive psychoactive drugs drug use for on the CNS. different classes of substances. Dependence Dependence refers to the condition where users of psychoactive substances develop a strong reliance and craving for the drug despite the often serious negative consequences of continued use. This dependence can be physical, with the body adapting and needing the drug to function normally, or psychological, with a cognitive/emotional attachment and perceived 'need' for the substance's effects. o Physiological adaptations that occur in response to the repeated use of a substance o The body becomes accustomed to using the drug and adjusts its functioning accordingly o Body craves the drug  Physical Dependence Mechanisms 1. Neurotransmitter 3. Withdrawal symptoms activation When the drug is stopped/removed/reduced Drug use  release of dopamine in  body tries to adjust to the absence of the drug the mesolimbic pathway in the E.g., headache, nausea, irritability, severe brain Triggers the reward pathway  pain, shaking, increased BP, seizures (Can be life-threatening) feelings of pleasure The severity and duration of withdrawal The brain then decreases the symptoms can be influenced by factors such number of synaptic dopamine as the substance's half-life, dosage, duration receptors  drug tolerance of use, and individual differences 2. Drug tolerance 4. Negative reinforcement Higher doses of the drug are To stop the feelings and symptoms of needed to achieve the same effect withdrawal  users take more of the drug due to decreased dopamine receptors. o Emotional and cognitive reliance on a substance to achieve a desired psychological state o Feeling/belief of needing the drug o Only certain drugs cause physical dependency, but ALL drugs can cause psychological dependency o As there is no withdrawal  can last forever  Psychological Dependence Mechanisms 1. Psychological Cravings 3. Cognitive & Emotional Aspects Cognitive processes related to the Desire to use the drug in anticipation of the perceived benefits of the drug. pleasurable effects. Emotional attachment to its effects. Can be triggered by various cues, Belief that the drug is necessary for normal emotional factors, social factors. functioning  positive reinforcement 2. Classical Conditioning 4. Positive Reinforcement Conditioned cues (triggers) become Increased use to feel the same rewarding associated with substance use due to repeated pairing. properties as before. When these cues are present, it is harder to resist. Categories of Psychoactive Drugs Category Brief description Stimulants Increase functioning of CNS Depressants Decrease functioning of CNS Alter perceptions, interpretation of Hallucinogens sensations Interact with opioid receptors in brain to Opioids* decrease pain  Stimulants Increase functioning of NS CNS Sympathetic NS Known as an ‘upper’ Examples: cocaine; amphetamines; Decreased caffeine appetite Long-term Increased heart rate Consequences Trigger underlying mental health Increased blood issues Sleep difficulties pressure Cognitive impairment Increased arousal and alertness Cardiovascular effects (e.g., blood pressure) Activation of dopamine and norepinephrine pathways NB neurotransmitters in mood regulation, attention, reward, pleasure, motivation  Decrease functioning of NS Depressants Enhancement of GABAergic Neurotransmission Known as an ‘downer’ Examples: alcohol; benzos; Long-term barbituates Consequences Depressive symptoms Sleep difficulties Impaired motor skills & Cognitive impairment (? coordination dementia) Increased Physical effects (e.g., withdrawal sedation/relaxation can be life-threatening; sexual Reduced reaction times, speed of dysfunction) thinking slowed Synergistic effects with other depressants (e.g., alcohol + benzos)  overdose GABA = primary inhibitory neurotransmitter Depressants enhance the effects of GABA  reduction in neuronal firing  Hallucinogens Altered perception Profound Changes in how the world is insights or perceived through the senses distress Deep realizations or Hallucinations anxiety from the Seeing, hearing, feeling things experience that are not really there Physical Sensory changes effects Long-term Distortions in how the senses Increased body interpret input from the world temperature, appetite Consequences Trigger underlying mental health loss, numbness issues They disrupt serotonin signaling in the Sleep difficulties brain, increasing serotonin levels in certain regions which can lead to Cognitive impairment hallucinations. Hallucinogen Persisting Common hallucinogens include LSD, Perception Disorder (HPPD)  Interact with Opioids Physical effects Pain relief (analgesia) opioid Euphoria & relaxation receptors in Increased drowsiness brain to reduce and sedation pain sensations Can cause respiratory depression (rate and depth of breathing Similar effects to reduced) depressants  but differentof mechanism Long-term Activation opioid receptors inhibits HighConsequences risk dependence and the transmission of pain signals. overdose Common opioids include morphine. Sleep difficulties Codeine, tramadol, heroin Changes in mood Increased pain sensitivity Cognitive impairment Any questions? Alexa Soule [email protected] om Room 2.18, Psychology Department University of Cape Town