Recreational Drugs

• Examples


  • Analgesics:
  • Reduce neurotransmitter activity
  • Prevent firing
  • Narcotics, control pain (e.g. heroin)
  • Depressants and sedatives:
  • Slow brain activity
  • Making message transmission
  • Between neurons less effective (e.g. alcohol)Hallucinogens:
  • Increase brain activity
  • Cause perceptual disturbance + hallucinations
  • Chemically like serotonin
  • Attach to post-synaptic receptor sites, are effective post-removal of neurons
• Drugs


  • Alcohol:
  • Inhibits sodium in sodium-potassium gateways
  • Raises GABA receptor responsiveness
  • PFC (social inhibition)
  • Hippocampus (memory)
  • Cerebellum (balance)
  • Limbic system (emotion)
  • Slows reflex, numb nerve ends at noradrenalin synapses
  • Heroin:
  • Mimics large endorphin release
  • Preventing pain messages
  • Facilitates dopamine floods + prevents GABA
  • Brain adjusts to increased activity (down/up-regulating), rapid tolerance
• Dopamine Reward System

  • Natural reward chemical
  • Link to reward-driven learning + positive reinforcement
  • For emotional regulation, cognitive functions, movement control + decision-making
  • High levels link to schizophrenia
  • Deficiency to behavior (ADHD) + movement disorders (Parkinson’s)
  • Dopamine receptor-rich areas, subcortical + ventral tegmental
  • At least 5 receptor types; combined for complex behavior
  • Psychoactive drugs (e.g. cocaine etc) manipulate reward system
  • Enhancing dopaminergic synapses activation or release
  • Prolonged high level exposure causes brain adaptation
• Up-regulation and down-regulation

  • Recreational or antipsychotic drugs change Dopamine activity
  • Cause downregulation or upregulation so brain functions 'normally'
  • Lower dopamine levels (causes dysphoria, anxiety, depression, discomfort + distress)
  • Downregulation
  • Reduce dopamine receptor sites
  • Desensitisatises
  • Causes heroin tolerance, more needed for same effect
  • Upregulation
  • Increases receptor sites sensitive to inhibitors, like GABA
  • Cause less reward
  • More drugs needed for same effect
  • Negative reinforcement replace positive; drug taken to feel normal and prevent withdrawal