Bio Psy - Recreational Drugs

• Addiction

  Dependency on substances, causing quitting to be a difficult process
• Recreational drugs

  • Cannabis
  • Alcohol
  • Amphetamine (MDMA)
  • Cocaine
  • Nicotine
  • Caffeine
• Cannabis

  Blocks receptor sites on the post synaptic neuron, so there is less activity in the neurons in the hippocampus, so reducing the efficiency of making new memories. It activates the dopamine neurons and release more dopamine. This can affect blood flow and reduces oxygen to the brain making the user feel relaxed, but also reducing attention and increasing memory loss
• Alcohol

  Increases serotonin, so makes the user feel happy. GABA is an amino acid and is responsible for generation of nerve impulses, and Alcohol also increases GABA. GABA inhibits the firing of neurons causing a sedative effect on brain function, making memory less efficient
• Amphetamine (MDMA)

  Increases dopamine and noradrenaline in the synapse. Uptake is prevented by blocking uptake pumps and inhibit the breakdown by enzymes, so there is increased levels of the neurotransmitters in the synapse, making the user feel alert. This may reduce memory performance when no longer producing necessary dopamine
• Cocaine

  Blocks the reuptake receptor dopamine into the presynaptic neuron, leading to over stimulation of dopamine on the post synaptic receptors. As dopamine is the reward pathway euphoria is reached, so the user feels happy. This may reduce memory performance when no longer producing necessary dopamine
• Nicotine

  Increases activity in the dopamine pathway by blocking the reuptake of dopamine on the presynaptic neuron, increasing pleasure. It also blocks the receptor sites of acetylcholine on the post synaptic neuron. Acetylcholine messages includes memory, alertness and muscle movement, so blocking these messages can lead to memory problems, loss of concentration and mobility problems
• Caffeine

  Binds to adenosine receptors, blocking the effects of adenosine, allowing dopamine to flow more freely. This brings on feelings of well-being, energy and alertness
• General AO1 Recreational Drugs on CNS

  Drugs are chemicals that can influence the role of neurotransmitters and hormones on behaviours by targeting the transmission process in the CNS at the synapse, blocking or mimicking NTMs to fit the receptor sites​
• Recreational Drugs on CNS 1 + 2 (example)

  • Drugs can block the reuptake pumps on the presynaptic neuron so that reuptake of the neurotransmitter won't occur. This causes a build-up of the NTM in the synapse, causing the post synaptic neuron to fire more frequently, passing on the message more frequently​
  • E.g. Prozac used to treat depression, which is cause by low levels of serotonin in the brain. Prozac is a selective serotonin reuptake inhibitor (SSIR), as it selectively stops the reuptake of serotonin into the presynaptic neuron
• Recreational drugs on CNS AO1 3

  • Drugs can mimic neurotransmitters, fitting into the post synaptic neuron receptors. These drugs wont be active NTMs but will be filling the receptor sites, leaving less receptors free for the actual NTMs to excite. As the receptor sites get stimulated, the presynaptic neuron reduces the amount of NTMs produces as it thinks there are enough. This leads to less firing of the neurons, and the message will not be passed on​
• Recreational Drugs on CNS AO1 4 (e.g.)

  • E.g. Chlorpromazine is used to treat schizophrenia. Schiz caused by high dopamine activity in the synapses. Chlorpromazine mimics dopamine + blocks receptor sites on the post synaptic neuron, decreasing the amount of dopamine produced and released from the presynaptic neuron, leading to less dopamine in the synapses​
• RDs and Addiction AO1 1

  • Recreational drugs (RDs) are brain altering chemical substances that are used for leisure purposes. Taking them changes mood, perception and conscious experience, and can lead to addiction. Addiction to drugs is a dependency on the substances, causing quitting to be a difficult process​
• RDs and addiction 2

  • RDs hack into the dopamine system. They increase the amount of dopamine in the body causing euphoria. This makes the brain decrease the natural production of dopamine (down regualation), so when the drug wears off, the person has less dopamine than needed for normal brain function, causing dysphoria, and motivating the person to take more drugs to stop feeling bad and to reproduce the euphoria. Reproduction causes further down regulation of dopamine, making the person dependent on the drugs​
• RDs and Addiction 3

  • Addiction occurs when a drug is no longer active in the nervous system. This can result in dangerous and unpleasant withdrawal symptoms due to the brain adapting to the changes imposed by the drugs so that it no longer operates normally. This can also lead to tolerance, where the user has to take higher doses to get the same effect.​
• RDs and Addiction 4

  • However, each person is different, so the drugs can influence them in different ways. In some cases the effect is determined by where the drug is taken, e.g. in situations where the user has never experienced taking drugs, and taking the regular dose can lead to overdose. This is bc the brain is conditioned to expect an increase of chemicals in some situations, which causes a down regulation of the NTM release, making way for the sudden rush of chemicals caused by the drugs. Explains cravings + relapse when return to places used to take drugs​
• Cannabis

  Mimic serotonin, blocks the receptors on post synaptic neurone, feeling relaxed and memory loss
• Cocaine

  Blocks reuptake of dopamine, increasing feelings of happiness and joy and causing animated behaviour
• Reward Pathway

  Hack into the reward pathway, increasing dopamine reach euphoria - feeling intense happiness and joy