biological explan of sz

• genetic factors - increase chances if genetically related
• grottesman - twin studies - 48% for mz - 17% for dz
• weakness grottsman - environmental factors mean theres never been a 100% concordance
• adoption studies - genetic support - higher chance if bio parents have than adoptive parents
• biochemical factors - come from post mortems and pet scans - abnormally high levels or neurotransmitters
• biochem evidence - antipsychotic drugs reduce symptoms by blocking dopamine receptors suggests cause is too much dopamine -drugs like amphetamines which increase sz symptoms increase dopamine
• biochem against - antipsychotics only work on positive symptoms doesn't explain all - dopamine link is correlational only
• neurological factors - neural correlates and abnormal brain structure
• Johnstone et al - comapred size of ventricles - 12/15 sz patients had larger ventricles
• against neurological - findings are correlational
• evolutionary explanations - advantage to sz - paranoia for survival - shamans religious leaders
• against evolutionary - little evidence and difficult to prove
• meehl - schizogene
• ripke - over 108 genes associated with the development of sz
• joseph - mz concordance rate 40.4%
• pro joseph - newer study than grottsman and sheilds
• issue with twin studies - mz twins are same gender and treated more similarly
• tienari - adoption study - those who have a bio aspect but no environmental 5.8% develop it - those who have bio and environmental 36% develop it
• effect of serotonin - clozapine which reduced sz symptoms blocks serotonin
• torrey - people with sz have 15% larger ventricles
• issue with ventricle size - might be effect of medication
• ventricle issue - correlational research only
• eval of bio - deterministic - assumes sz is inevitable
• eval of bio - reductionist - tried to reduce casue of sz to one thing