Schizophrenia: Biochemical Factors
- Created by: Olivia
- Created on: 06-03-13 21:46
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- Schizophrenia: Biochemical Factors
- Genetic factors operate through brain mechanisms.
- Brain is composed of millions of neurons - main anatomical structure of brain
- Neurotransmitter- chemical messages transmit impulses across synapses between neurons
- Neurotransmitters implicated in schiz.
- Dopamine Hypothesis - Schiz. results from excess dopamine activity at certain synaptic sites
- Could be caused by excess dopamine by presynaptic neurons, excess of dopamine receptors
- Phenothiazines are effective in alleviating some of the major symptoms of schiz.
- Clozapine (most clinically effective treatments) once thought to be weak at blocking dopamine receptors
- FARDE ET AL (1992): Positron tomography scans have shown it occupies dopamin sites to same extent as other neuroleptic drugs
- Amphetamines can induce symptoms of acute paranoid schiz. in unaffected people + increase severity of symptoms in previously diagnosed people
- WONG ET AL (1986): Found a two fold increase in the desity of dopamine receptor sites in patients who had never been treated with drugs compared to ones who had + control group
- L-Dopa (Parkinson disease) acts by increasing dopamine levels. Can produce schiz. symptoms in previously unaffected individuals
- Phenothiazines do not work for everyone diagnosed - only alleviate postive symptoms
- However, different types of schiz. which might have underlying causes
- It is likely that dopamine is implicated in causing schizophrenia, but this an over simplified explanation
- Could be caused by excess dopamine by presynaptic neurons, excess of dopamine receptors
- Phenothiazines do not work for everyone diagnosed - only alleviate postive symptoms
- However, different types of schiz. which might have underlying causes
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