Schizophrenia Flashcards
what are the two positive symptoms of Sz?
delusions = persistent irrational or false beliefs i.e. panoia hallucinations = any sensory experience that is not grounded in reality
what are two negative symptoms of Sz?
avolition = lack of motivation to complete everyday tasks
speech poverty = reduction in the quality and or quantity of speech.
what are the two classification manuals and how do they differ?
ICD and DSM. DSM requires 6 months of negative impact on functioning whereas ICD does not
what is inter-rater reliability?
whether two psychologists give the same diagnosis for the same patient
what is diagnostic congruence?
wether the same individual will be diagnosed the same way with two diagnosis manuals.
what is symptom overlap?
when two conditions have very similar symptoms i.e. Sz and bipolar
what is co-morbidity?
when two conditions frequently occur together. i.e. Sz and PTSD.
evaluate the diagnosis and classification of Sz.
1) Chenieaux: psychologist 1: ICD = 44 DSM = 24. psychologist 2: ICD = 26 DSM = 13
2) Women less likely to be diagnosed as they are able to function better with the same symptoms
3) minorities more likely to be diagnosed because they are more open about hearing voices in their culture.
what is the dopamine hypothesis?
hyperdopaminergia = high levels of dopamine in the sub cortex hypodopaminergia = low levels of dopamine in the cortex
what are some genetic/biological causes of Sz?
- candidate genes
- neural correlates
- dopamine hypothesis
what does polygenic mean?
there are multiple genes involves in Sz, each one increases vulnerability to getting the disorder.
what are the neural correlates of positive symptoms?
Allen et al: found that there is lowered activity in the superior temporal gyrus and the anterior cingulate gyrus in patients who experience auditory hallucinations.
what are the neural correlates of negative symptoms?
Juckel et al. found that there is lowered activity in the ventral striatum of patients who experienced avolition.
evaluate biological causes of Sz.
1) L-Dopa and amphetamines increase levels of dopamine in the brain and can induce Sz symptoms
2) Ripke found 108 possible candidate genes, many involved in the dopamine system
3) Gottesman twin study found concordance of 48% for MZ and 17% for DZ twins.
4) role of glutamate now thought to be as, if not more, important
what are the two types of psychological explanation for Sz?
central control and family dysfunction
what is EE?
unlike double bind - which explains Sz as only a result of family dysfunction, EE acts as the stressor in the diathesis stress model. it involves: hostility, criticism and emotional over-involvement.
what is central control?
ability to suppress automatic thoughts
evaluate psychological explanations of Sz.
1) sterling et al. found Sz patients took twice as long to complete the stroop test than normal people
2) King et al. longitudinal study that seems to suggest that relapse causes EE rather than EE causing relapse
3) success of family therapy designed to reduce EE implies EE causes relapse
4) Kavanagh meta analysis found relapse rates in high EE families was 48% in comparison to 21% in low EE families.
what are the two types of anti-psychotics and give an example?
typical = chlorpromazine atypical = clozapine
how to anti-psychotics work?
block dopamine receptors in the synapse - specifically d2. this reduces dopamine activity and therefor lowers positive symptoms
what is the difference between typical and atypical antipsychotics?
atypical also works on the serotonin system and so reduces negative symptoms as well. they are also more effective and have fewer side effects.
what is the typical daily dose of each anti-psychotic?
typical = 400-800mg daily atypical = 300-450mg daily
what are the side effects of each anti-psychotic?
typical = Tardive dyskinesia in 32% and neuroleptic malignant syndrome which can cause death atypical = Tardive dyskinesia in 13% of cases, no NMS but some cases of agranulocytosis. weight gain also less severe.
evaluate biological treatments for Sz.
1) Thornley meta analysis found that chlorpromazine was consistently better than a placebo
2) atypical anti-psychotics are effective in 30-50% of cases where typical were not effective
3) Leucht et al. effect size of 0.5 for acute cases and 0.9 for relapse cases with typical anti-psychotics
4) NICE estimates that neither will work for around 24% of patients
5) side effects may cause some people not to comply with medication
what are the three psychological therapies?
family therapy, CBT and token economy
how is CBT used?
to challenge the irrational beliefs of patients and to provide them with alternative explanations for their delusions
how is token economy used?
only in institutional settings such as psychiatric hospitals. tokens act as secondary reinforcers to encourage behaviour such as maintaining hygiene that can be lost in an institutionalised setting.
how is family therapy used?
patient attends with their family. designed to reduce anger, guilt, EE and conflict and increase understanding and balance. It also increases compliance with medication.
evaluate the use of psychological therapies.
1) token economy only suitable for use inside an institution and may lead to discrimination against more serious cases who find it much harder to function.
2) Jones et al. performed a meta analysis and found no significant difference in the functioning of patients after CBT.
3) pharaoh found rates of relapse and compliance with medication were significantly improved by family therapy.
4) most samples for these studies are small due to difficulty with random allocation so generalisation is less possible.
describe Meehls diathesis stress model.
diathesis = 1 particular genes, the schizogene stress = any event in childhood that triggers onset - usually schizophregenic mother
describe the modern diathesis stress model
diathesis = any event in early childhood + the influence of candidate genes stress = any event in later childhood that causes onset
evaluate the diathesis stress model.
1) Tienari: 19000 Finnish adoptees. high risk + high EE = 27%. high risk + low EE = 5%.
2) Houston et al: early sexual trauma as a diathesis and cannabis use as a stressor. no trauma + no cannabis = 0.5%. trauma and cannabis = 12.5%. intermediate = 0.6 and 2.2%.
3) Tarrier et al. found more improvement in patients placed in two treatment group than one treatment group.
