Schizophrenia Flashcards
Genetic Explanations of Schizophrenia - 5 (AO1)
- Grottesman found MZ twins have 48% of shared Schz + as genetic similarity increases so does risk of developing Schz
- However, concordance rate not 100% must be some environmental factors
- candidate genes are individual genes that increase risk of Schz
- Schz is polygenic + aetiologically heterogeneous ( different combinations of factors + genes implicated)
why is schz describes as aetiologically heterogeneous ?
different combination of factors + genes implicated in condition
what is hypodopaminergia ?
- low levels of dopamine in prefrontal cortex (thinking) linked to negative symptoms such as avolition
what is hyperdopaminergia ?
- excess dopamine in subcortex is linked to positive symptoms such as hallucinations and delusions
What symptoms does DSM focus on ?
positive symptoms for more than 6 months
What symptoms does ICD focus on ?
negative symptoms for more than 1 month
Explain what is meant by positive symptoms of schizophrenia and give two examples ?
- additional experiences
- hallucinations = unusual sensory experiences
- delusions = irrational beliefs
Explain what is meant by negative symptoms of schizophrenia and give two examples ?
- loss of usual abilities
- avolition = lack of motivation / energy
- speech poverty
What are the 5 main issues with the methods of C+D for Schz ?
- culture bias
- low inter-rater reliability
- gender bias
- symptom overlap
- co - morbidity
what is co-morbidity ?
2 conditions co-exist in the same individual at the same time
what is symptom overlap ?
symptoms from one disorder are present in another eg. BPD + Schz
Strengths of Biological exp
(adoption + amphetamine )
- RS from adoption studies:
-Tienari = found there was a higher percentage of adoptees whose mother has schz were diagnosed compared to the control group - therefore isolates environmental influences
- supports genetic (nature)
- amphetamine is a drug that increases dopamine levels
- can induce symptoms in non sufferers
- therefore supports dopamine hypothesis
2 weaknesses of biological explanations
- biological reductionism = ignores psychological factors therefore diathesis stress is better alternative
- problems with determining cause + effect = unusual dopamine disorder may be consequence of disorder rather than cause
what is the psychological explanation for Schz ?
- family dysfunction ( Schz mother, expressed emotion , double bind theory )
- cognitive ( metrarepresentation + central control )
what is research support for central control dysfunction ?
- study compared performance on Stroop test of a group of Schizhophrenics compared to control group
- found schizophrenic’s took twice as long to name colours compared to control group
- due to inability to supress automatic thoughts ie. reading out word
