Explain Methods of Modifying Behaviour - Antipsychotic Drugs

Question 1

Explain conventional antipsychotics…

Answer 1

Affect neurotransmission through blocking the action of dopamine on D2 receptor sites and in the mesolimbic pathway, leading to a decline in positive symptoms

Question 2

Explain how conventional antipsychotics work…

Answer 2

After dopamine is released into the synapse, receptors are blockaded by chlorpromazine, reducing activity

Presynaptic neuron releases more dopamine

Production of dopamine drops due to depletion, and the amount of dopamine in the synapse decreases

Neural activity decreases

Question 3

Explain atypical antipsychotics…

Answer 3

Act as dopamine antagonists, but the precise mechanisms is not yet clear

Question 4

Explain differences between the two drugs…

Answer 4

Atypical drugs are received by fewer D2 receptors, more D1 and D4 receptors, and antagonise receptor 5-HT2A

Phillip Seeman’s (2002) ‘fast-off’ theory states that atypical drugs bind more loosely and don’t bind long enough to cause positive symptoms

‘Half-life’ of atypical drugs are shorter as occupancy of D2 receptors falls off within 24 hours, while conventional drugs fall off after 24 hours