SCHIZOPHRENIA Flashcards
(38 cards)
What did Gottesman find?
genetic basis of sz
- risk of sz increases with genetic similarity to a relative with sz
- he found a concordance rate of 48% for identical twins, 17% for siblings, 2% for 1st cousin/aunt
What did Ripke find?
genetic basis of sz
Sz is polygenic more than one gene causes it
- RIPKE studied 37K with Sz compared to 113K controls, 108 genetic variations associated with Sz increase risk as more genes that cause it
- mutation of genes can increase the risk of Sz (Brown et al)
AO3 of Genetic Basis
- TIENARI et al + GOTTESMAN found adopted children of biological Sz mothers are more likely to develop Sz than adopted children of mothers w/o Sz
- people who share genetics also share environments. Unclear if risk of Sz is due to genetic influences or environmental factors => biologically reductionist
- Marked et al = 67% of people w/Sz & psychotic disorders reported at least 1 childhood trauma. opposed to 38% of a matched group w/non-psychotic disorders. Therefore genetic factors alone cannot provide a complete explanation for Sz.
Neural correlates definition
relationship between levels of activity in certain structures of the brain & symptoms of Sz
Avolition
neural correlates
lack of motivation or ability to do tasks or activities that have an end goal, such as paying bills or attending a school function, poor hygiene, lack of energy
Negative Symptoms
neural correlates
Avolition is linked to the Ventral Striatum (VS). JUCKEL found lower levels of activity in the VS in Sz patients than controls = negative correlation
Positive Symptoms
neural Correlates
auditory hallucinations linked to lower activity in the Anterior Cingulate Gyrus & the superior temporal gyrus => negative correlation
Dopamine Hypothesis
neural correlates
Antipsychotics used to treat Sz lower dopamine activity caused symptoms similar to those with Parkinson’s which is associated with low dopamine activity. Therefore Sz can be a result of high dopamine activity HYPERDOPAMINERGIA. e.g. increased dopamine activity in pathways of Broca’s area explain speech poverty. HYPODOPAMINERGIA (LOW DA) - also causes negative Sz symptoms
AO3 Neural Correlates
- explanation solely focuses on correlation between activity of the brain & symptoms of Sz. Doesn’t establish cause & effect. So its uncertain whether the symptoms cause the lower activity or vice versa.
- Neural explanations criticised as reductionist, explaining Sz at a very basic level. Role of upbringing, learning & emotions not considered weakening this as a full explanation.
+ Amphetamines increase DA, worsening the symptoms in Sz patients & induce symptoms to those w/o Sz (Tauscher et al)
- Glutamate -> post-mortem & live scans of Sz patients show raised levels of neurotransmitters Glutamate in several regions. also several candidate genes for Sz are involved in glutamate production
Schizophrenogenic Mother (Family Dysfunction)
Reicheman noted many Sz patients described their mother as cold, uncaring, rejecting, unemotional, controlling, tense & seceretive = schizophrenogenic mother
what does a schizophrenogenic mother create
Family Dysfunction
leads to an atmosphere of distrust & development of paranoid thoughts become delusions
Double bind theory
Family Dysfunction
BATESON - if children received mixed messages from parents they learn not to trust others or their own feelings & perceptions. children are punished for doing what’s asked e.g. given a hug and pushed away (withdrawal of love = punishment). They lose grip on reality which leads to delusions & disorganised thinking.
Expressed Emotion (EE) (Family Dysfunction)
-/ve emotional climates = increased degree of EE> EE is a family communication style in the home which included levels of certain emotions - criticism & emotional over involvement. this has been linked to relapse in sufferers returning to the home after treatment
AO3 Family Dysfunction
+ BERGER found schizophrenics reported higher recall of double-bind statements by their mothers than non-Sz. more situations of reward & punishment leading to delusions and confusion. (insecure attachment)
- shown only small % of women who fit the ‘Sz mother’ actually produced sz children. it also blames the mother for something that might not be entirely her fault causing further trauma.
- many patients with sz found to not have a schizophrenogenic mother
Cognitive explanations for Sz
- Symptoms of Sz are due to abnormal information processing
- There is a link between cognition and biology – if activity is low in certain areas of the brain then information in that area will not be processed accurately
what are the two kinds of dysfunctional thought processing?
- Metarepresentation
- Central Control Dysfunction
what is Metarepresentation?
reflecting on thoughts and behaviour, understanding our own and other’s behaviours
what is central control dysfunction?
Ability to supress automatic impulses and act with intention
what happens when metarepresentation is faulty?
disrupt ability to recognise our own actions and think someone else is carrying them out.
explains hallucinations and hearing voices or having thoughts inserted by others
what happens when central control dysfunction is faulty?
if this is faulty Sz patients can’t suppress their actions when a word triggers them, its an automatic response
AO3 of Cognitive Explanations
+ Stirling found people with Sz have a lack of central control. Unable to suppress automatic responses when performing tasks. (stroop test) people with sz have difficulty taking twice as long in comparison. Supports firth that said sz have central control dysfunction
- issues identifying cause and effect, do the symptoms of sz cause cognitive dysfunction or vice versa
what are antipsychotics?
form of medication to reduce symptoms of Sz, can be prescribed long term or short term, depending on the severity of the Sz and the type of symptoms
- typical and atypical antipsychotics
What do Typical Antipsychotics do?
- Reduces activity of dopamine within the brain, antagonists (reduce activity of neurotransmitters). Blocking dopamine receptors this reduces action of dopamine.
- they reduce the severity of +/ve symptoms
Name a typical antipsychotic
Chlorpromazine
Developed in the 1950’s, can be taken as tablet, syrup or injection – max dosage of 1000mg daily
Also has sedative effects – calms an individual with high anxiety
blocks dopamine receptors to reduce DA
