The dopamine hypothesis

What is dopamine?

• a neurotransmitter involved in initiating movement and has a major role in reward motivated behaviour

• Believed to work differently in the brain of a patient with schizophrenia resulting in symptoms

• Genetic factors are liked to faulty dopaminergic systems

What is the original hypothesis?

High levels → hyperdopaminergic → mesolimbic pathway → positive symptoms → increased no. D2 receptors

What is the revised hypothesis?

Low levels → hypodopaminergic → mesocortical pathway → negative symptoms

Evaluation of the dopamine hypothesis

• Supporting evidence - Curren et al - Kessler et al

• Issues with causation - Lloyd et al

• Biological reductionism - Thorney et al