Recreational Drugs

• What are SSRIs?

  > Selective Seretonin Reuptake Inhibitions

  > Low levels of serotonin link to depression

  > Type of antidepressant drug that blocks the reabsorption of serotonin by neurons

  > Leaves more seretonin at the synapse to be taken up again by receptors of other neurons
• How do drugs affect synaptic transmission?

  > Changes are dependant upon the mode of action

  > Mode of action - how the drug acts upon different neurotransmitters in the brain

  > Different drugs have different modes of action
• What is the reward pathway and how do drugs affect it?

  > Causes pleasure and reward

  > If it feels good, we will repeat the behaviour

  > Drugs hijack the reward system, producing pleasurable feelings

  > Pathway includes the nucleus accumbens and vental tegmental areas of the brain
• How does dopamine lead to addiction?

  > Most drugs increase dopamine in the brain

  > Leads to intense pleasure and euphoria

  > Brain quickly adapts to the excess dopamine and down regulate its own production

  > Once the drug wears off, the person is left with less dopamine then before

  > Motivates someone to take more

  > Over time, the body becomes dependant on the drug so the person takes more to avoid withdrawal
• What is a depressant?

  A drug that reduces the ability of the synapses to work effectively, slowing down brain activities (alcohol, Xanax)
• What is a stimulant?

  A drug that speeds up the CNS. Make people feel 'supercharged with energy and focus' (caffeine, cocaine)
• What are the effects of alcohol?

  > Coordination is impaired

  > Heart and blood pressure increase

  > Vision is blurred + speech is slurred

  > Mode of action (GIN) - Gaba - slows speed that messages are transferred at.

  • Alcohol reduces effect of inhibitors mechanism (don't behave in a socially acceptable manner)
  • Anaesthetises the never endings of noradrenaline
• What are the effects of heroin? (Depressant)

  > Causes euphoria and analgesia

  > Depresses respiration

  > Slows the movement of food through the intestines

  > Mode of action (GOD) - Gaba- morphine binds to opioid receptors and inhibits the action of GABA

  • Oipioid receptors - concentrated in the reward pathway of the brain
  • Dopamine - can flood the synaptic gap activating the reward system and the activating the pain pathway
• What are the effects of nicotine? (Depressant & Stimulant)

  > Arouses the brain to a state of increased alertness

  > Increases heart rate and blood pressure

  > At high levels, relaxes muscles and triggers the release of neurotransmitters that may reduce stress

  > Reduces circulation to extremities

  > Mode of action (SAD) - Sympathetic nervous system activated, adrenaline is produced

  • Acetylcholine synapses are stimulated
  • increases Dopamine