The biological theory of schizophrenia

Effect of dopamine on scz

* People with scz have too much of the %%neurotransmitter%% %%dopamine%% in their brains.
* This could cause people to become erratic, experiencing hallucinations and delusions.
* Messages from %%dopaminergic neurons%% that transmit %%dopamine%% fire too easily, leading to symptoms of scz.
* High humber of %%dopamine receptors%% on certain neurons.
* This leads to too much dopamine binding and therefore more neurone firing across synapses.
* This explains why people with scz may believe, see or hear something that doesn’t exist.

What is dopamine linked to?

Movement, perception, attention and mood

Effect of brain structure on scz

* Lower blood flow in the %%frontal cortex%% region of the brain, this are is less frequently activated during certain tasks, this area of the brain is also smaller.
* The %%prefrontal cortex%%, the control centre of the brain, is defective. This explains why people with scz lose control over psychological functioning such as being organised.
* The %%temporal lobes%% are lower in volume due to the lack of grey matter.
* The %%hippocampus%%, which has a role in forming memories and the emotions that go with them, is smaller in volume and the more severe the disorder the more deflated the part of the brain is.

Criticisms

* **Focuses on** %%**nature**%%**.** The brain working differently is not enough to cause the disorder itself since the brain still need to interact with the environment to produce symptoms like hallucinations.
* %%**Brain dysfunction**%% **could be an effect of scz, not a cause**. Evidence comes from post mortals or scans after diagnosis and researchers can’t tell what happens first. Brain dysfunction could be a symptom.
* **Too** %%**deterministic**%%**.** Too simplistic to explain such complex disorder by just looking at one neurochemical. A number of different factors may be working together to cause scz.