Please enable JavaScript.
Coggle requires JavaScript to display documents.
biological explanations for sz - Coggle Diagram
biological explanations for sz
genetics
evaluation
strength- research support from large scale family study.findings- as percentage of genes shared increased so did risk for developing sz. Mz twins (share 100% of genes) had 48% concordance rate whereas DZ twins (share 50% genes) had 17% concordance rate, showing must be genetic risk factor for developing sz
limitation- evidence for the role of genes is flawed because MZ twins are genetically identical but concordance rate is not 100%. most twins share genes and environment which means it is difficult to conclude whether its biological or genetic factors providing risk for sz. suggests other factors such as hostile family relationships in environment may need to be considered as risk and genetic explanation is not complete
Sz is heritable/inherited through the generations through transmission of genes/DNA
inheritance of SZ is complex
candidate genes associated with the risk of schizophrenia include those associated with coding for a number of neurotransmitters
hundreds of genes have been identified as potential risk factors (polygenic)
evaluation
other explanations such as psychological explanations (family dysfunction) means biological explanations not fully comprehensive alone
biological explanation reductionist
practical application- biological explanation has allowed researchers to develop treatments to reduce symptoms such as drug therapies, so explanation has positive impact in the real world
neural correlates- dopamine hypothesis
hyperdopaminergia
high levels of dopamine in the sub cortex
eg. excess dopamine in brocas area may result in speech poverty
subcortex= central areas of the brain
hypodopaminergia
low levels of dopamine in the pre frontal cortex
prefrontal cortex= responsible for thinking and design making
evaluation
dopamine hypothesis supported by evidence for effectiveness of antipsychotic drugs. assuming high dopamine levels result in symptoms of schizophrenia means should be improvement if dopamine levels are lowered. Dopamine antagonists, which block the activity of dopamine in the brain, have reduced positive symptoms of schizophrenia (e.g. Hallucinations).
contradictory evidence for dopamine hypothesis as not all patients benefit from antipsychotic drugs which only work on dopamine system.Clozapine is an atypical antipsychotic drug, which works on both dopamine and serotonin systems. It is effective in reducing the symptoms of schizophrenia. suggests that a dopamine imbalance is not the only cause of schizophrenia and therefore the dopamine hypothesis is not complete
dopamine is a neurotransmitter associated with attention and motivation
dopamine helps to guide attention, so disturbances may lead to problems with perception, attention and thought
imbalance could be inherited or due to environmental factors