schizophrenia Flashcards
define schizophrenia
group of psychotic disorders that are characterised by a loss of contact with reality
features of schizophrenia
- prevalence rate of 1%
- typically begins in late teens or early 20s
- episodic illness- period of psychotic disorders as well as normal functioning
- starts with low mood or anxiety, and active phase follows with specific symptoms
- psychotic episodes can last from 1-6 months to a year
- 2/3 make substantial progress
- can be acute (sudden) or chronic (gradual)
define positive symptoms
reflects an excess of distortion of normal functions
positive symptoms of schizophrenia
- hallucinations- perceptual disturbances, including auditory and visual
- delusions- believing things aren’t true
-disorganised speech- echolalia, nonsense of gibberish
define negative symptoms
reduction or loss of normal functions
negative symptoms of schizophrenia
- speech poverty/alogia- reduction in quality and amount of speech
- avolition- lack of desire or motivation for anything
- affective flattening- loss of expression and emotional response, unexpected emotions
- anhedonia- lack of pleasure seeking behaviours
- catatonic behaviour- affect a persons ability to speak, move or respond to their environment, motionless, frantic movements
diagnosis of schizophrenia
- DSM states they must show at least two of delusions, hallucinations, disorganised speech, catatonic behaviour or any negative symptoms- one from the first 3
- must be present for at least 6 months
- subtypes are not recognised in DSM-V- paranoid, disorganised or catatonic
how are mental disorders diagnosed
- DSM 5 is the american manual used to classify and describe over 200 disorders
- ICD 100 is used in Europe
define reliability
consistency in how the classification system produces the same diagnosis for a particular set of symptoms
define inter rated reliability with schizophrenia
different clinicians give identical diagnosis to the same patient
define test retest reliability in terms of schizophrenia
diagnosis is consistent over time using the same information
evaluation of reliability of diagnosis strengths
+ help provide clinicians with common language, permitting communication
evaluation of reliability of diagnosis weaknesses
- experienced psychiatrists only agree 54% as seen by Beck et al and inter rater reliability correlation found as low as 0.11
- misinterpretation and subjective as “bizarre delusions” can be interpreted differently- found with psychiatrists in US who only had inter rated reliability of 0.4 when differentiating
- variation between countries- new york psychiatrist twice as likely to diagnose schizophrenia than london, who were 2x more likely to diagnose depression
- test retest reliability is low- 37% concordance rate
=> however improv,events with cognitive screening like RBANS found test retest reliability to be as high as 0.84
define validity and the different types
how accurately is schizophrenia diagnosed and that the classification system measures what it intends to measure
aetiological- extent to which cause of schizophrenia is the same
descriptive- extent to which individuals diagnosed with the same disorder are similar
predictive- extent to which diagnostic categories predict the outcome of treatment
define symptom overlap
extent to which a symptom appears in more than one disorder
- bipolar disorder and schizophrenia both share delusions and avolition as a symptom
define comorbidity
presence of one or more additional disorders co-occurring with primary disorder, like anxiety and depression commonly occurring with schizophrenia
evaluation of validity of schizophrenia diagnosis strengths
+ more modern system show greater validity
+ diagnostic categories are justifiable and give clinicians an agreed framework to work so effective therapies can be developed
evaluation of validity of schizophrenia diagnosis weaknesses
- too many variations of outcome as 20% recover and may never have an episode whereas 10% may commit suicide
- rosenhan used pseudo patients in a psychotic unit and once admitted, they behaved normally but staff at the unit still noted their behaviour as symptoms
- symptom overload and comorbidity makes it hard- 50% of patients also had depression
- gender bias- castle et al argues criteria is too strict as rate of schizophrenia in men was 2x more than women, also found that administer of oestrogen reduces schizo symptoms
- culture bias- afro-caribbean are diagnosed more with schizophrenia than white people, despite same rate of diagnosis within the caribbean (8x higher), or perhaps stressors in britain like racism increases rate of schizo
evaluation of symptoms overlap
+ ellason and ross found those with DID have more symptoms of schizophrenia than people actually with it
- makes it difficult for clinicians to diagnose
- misdiagnosis can lead to delay in receiving treatment
evaluation of comorbidity
+ buckley estimates comorbid depression occurs in 50% of sufferers
- difficulty in validity of diagnosis
- leads to less effective treatments and lower levels of functioning
- sufferers with comorbid disorders are generally excluded from research but for, majority of patients
- high levels of co-morbidity could be evidence for separate sub types of schizophrenia
how can genetics explain schizophrenia
- research uses twin and family studies to look at concordance rates
- gene mapping studies have been used to find genetic material among sufferers
- adoption studies help to entangle genes and environment
evaluation of genetics to explain schizophrenia strengths
+ concordance rate in MZ twins was 40% compared to 7% for DZ
+ Gurling found chromosomes 8p21-22 and PCM1 gene in schizophrenia sufferers
+ study with adopted children found those with biological mothers with schizo we’re more likely to develop it
evaluation of genetics to explain schizo weaknesses
- study into 164 women who had children adopted away found 14 adoptees developed schizophrenia showing being reared into a healthy adoptive family had a protective effect
- diathesis stress model and other factors
- socially Mz twins can be treated the same and thus more likely to be concordant
- concordance rate not 100% for MZ twins
how can dopamine hypothesis explain schizophrenia
- too much dopamine can lead to onset of schizophrenia as it causes hallucinations and delusions (hyperdopaminergia)
- thought to have abnormally high number of D2 receptors, resulting in more dopamine binding
- recently, also found high levels of dopamine in NAC ads associated with positive symptoms, and deficit in VTA associated with negative (hypodopaminergia)
evaluation of dopamine hypothesis strengths
+ drug therapies like antipsychotic drugs work by inhibiting dopamine activity
+ post mortem studies show excess dopamine in limbic systems of sufferers
+ hypodopaminergia in prefrontal cortex found to lead to speech poverty and avolition, linking to new link with negative symptoms
evaluation of dopamine hypothesis weaknesses
- high levels only associated with positive symptoms, and cannot explain negative
- description rather than causation
- Noil (2009) found antipsychotics only alleviate hallucination and delusions for 1/3 of patients
- not the only neurotransmitter involved- glutamate and serotonin
- bias as pharmaceutical companies may push for drug therapies so they can profit
how can neural correlates explain schizophrenia
- those with schizophrenia tend to have symmetrical brains
- reduced volume of grey matter
- enlarged ventricles, particularly those with negative symptoms
- hippocampus dysfunction influences dopamine release in basal ganglia
- deficits in nerve connections between hippocampus and prefrontal cortex
evaluation of neural correlates strengths
+ johnstone et al compared size of ventricles and found those with schizo had enlarged ventricles
evaluation of neural correlates weaknesses
- unclear whether schizo is caused by structural abnormalities or it is as a result of the disease
- enlarged ventricles are not, associated with negative symptoms and cannot explain all
- not all those with enlarged ventricles, symmetrical brain etc have schizo
double bind theory as an explanation for schizophrenia
- conflicting messages from their parents
- interactions prevent the development of an internally coherent construction of reality
- leads to disorganised thinking as they cannot meet the unrealistic demands of the parent
expressed emotion as an explanation for schizophrenia
- family communicating style that involved criticism and emotional over involvement
- leading to individual withdrawing themselves and wanting to escape
- primarily associated with relapse in patients
evaluation of family dysfunction as an explanation of schizophrenia strengths
+ 51% relapse rates in those in high EE homes and only 13% in low EE homes
+ high prevalence of EE in Indian and Iranian cultures, and also found they have higher prevalence of schizophrenia
+ success of treatment to that aim to reduce family EE
evaluation of family dysfunction as an explanation of schizophrenia weaknesses
- unsure whether it is cause or effect of disorder
- high EE also found in other disorders like depression
- socially sensitive- seem to “blame the family”
- based on case studies and interviews- subjective and social desirability bias
cognitive explanations of schizophrenia
- dysfunctional thought processing - suffer from metacognitive dysfunction which is when they struggle to reflect on their own thoughts
- inadequate information processing leads to misinterpretation of experiences and delusions
- cognitive biases- egocentric bias which is when they perceive themselves as the central component in events
- attention deficit theory- faulty filter for thoughts in schizophrenia patients that cannot regulate dopamine in the brain and leads to positive symptoms
- helmsley model- break down in relationship between memory and perception, which leads to sensory overload as brain cannot decipher between memory (schemas) and external source
evaluation of cognitive explanations of schizophrenia strengths
+ CBT has been successful
+ stirling et al found patients with schizophrenia took twice as long to complete stroll test than neurotypical, showing faulty central control skills
evaluation of cognitive explanations of schizophrenia weaknesses
- reductionist- people can have cognitive biases and not develop schizophrenia, does not consider biology
- does not explain cause
- little empirical evidence
socio cultural factors of schizophrenia
social causation hypothesis- people with low social status more likely to suffer
evaluation social cultural factors of schizophrenia
+ research shows people born in deprived areas were more likely to develop schizo
- results are corelstional
- social drift hypothesis- people with schizophrenia in deprived areas as having it gives them lower status
how do typical antipsychotic drugs work (chlorpromazine)
- help treat positive symptoms like hallucinations
- work by reducing effect of dopamine
- dopamine antagonists- bind to but do not stimulate dopamine receptors
evaluation of typical antipsychotic drugs strengths
+ found 19% relapse with treatment and 55% relapse with placebo
=> however, 45% in placebo still recovered
evaluation of typical antipsychotic drugs weaknesses
- only make a difference in those living in high EE environments- consider other factors
- 30% taking meds also develop TD- dysfunction of movement of lips and face
how do atypical antipsychotic drugs work (clozapine)
- can treat positive and negative symptoms
- work by temporarily occupying the domaine receptors and then dissociating to allow for normal dopamine transmission
- can also act on serotonin system
evaluation of atypical antipsychotic drugs strengths
+ more effective in general than typical antipsychotic
+ less side effects, only 5% get TD
+ also improvements in mood and functioning, which is good considering comorbidity with depression
evaluation of atypical antipsychotic drugs weaknesses
- still other side effects like weight gain
evaluation of drug therapy (weaknesses)
- treat symptoms jot cause
- side effects
- discourage patient responsibility- determinist, lack of control
- psychology and the economy
- best combined with other treatments like CBT
- problems with compliance- only 40-50% with schizo stick to their meds
features of family therapy and how does it work
- provide support for carers to make family life less stressful
- commonly used with drug treatments
- psychoeducation- understand schizo and how to deal with it
- create alliance with relatives
- reduce emotional climate and expressions of anger and guilt
- develop problem solving skills
- maintain separation when neesed
evaluation of family therapy strengths
+ pharaoh et al found family therapy increased patients compliance with medication and reduced relapse
=> however, critique of methodology, especially from studies in china, that did not use random allocation nor double blind procedures
+ works best in conjunction with antipsychotics- relapse half as likely
+ economic benefit- NICE review found cost savings due to reduction in relapse and cut of hospitalisation in long term
+ additional benefit to family by improving family and relationship quality
evaluation of family therapy weaknesses
- doesn’t always work- those with no carer and no family therapy still had low relapse rates
- family needs to be willing to change
features and overview of CBT
- helps to identify and challenge irrational beliefs and thoughts
- evaluate the validity of their beliefs and delusions
- distorted thinking is identified and therapist points out ways to cope with it
different steps of CBT
- assessment- patient expresses thoughts and goals
- engagement- therapist empathises with the patient’s feelings and sets up a strong relationship
- ABC model- beliefs are rationalised and disputed
- normalisation- therapist provides information in prevalence of unusual experiences to rescue anxiety and sense of isolation
- critical collaborative analysis- helps patient to understand illogical deductions, emphasis with them
- developing alternative explanations- help construct new ides for irrational beliefs
evaluation of CBT strengths
+ effective in reducing hospitalisation rates and symptom severity
evaluation of CBT weaknesses
- effectiveness depends on stage of the disorder, like group based CBT is more effective after stabilisation of symptoms using medication
- not available to everyone- only offered 1 in 10, scotland more likely to use antipsychotic medication
- it is not independent of antipsychotic medication so we are unsure which is the cause
- benefits may be overstated where there was only a small effect on symptoms
- only treats symptoms and not the cause
- style does not work for everyone, some may be too paranoid to trust the therapist
how does token economy work
- based on operant conditioning, where desirable behaviours are encouraged using reinforcement
- normally used to treat negative symptoms
- rewards are given as secondary reinforcers after patient engages in desirable behaviours, including eating, washing etc
- they can be exchanged for primary reinforcers- which is any prize that gives pleasure and do not depend in learning
- secondary reinforcers initially have no value but when paired with primary reinforcers, it is is associated with the same response
how can token economies be made more effective
- must be related alongside behaviour and immediately after to be associated (classical conditioning)
- more variety leads to higher response as individuals can choose prizes they prefer
evaluation of token economy strengths
+ Dickenson et al found 11/13 patients found beneficial effects that were attributed to token economies
+ significant improvements in behaviour, and thus useful to the economy
evaluation of token economy weaknesses
- less effective outside of hospital as they are constantly monitored and can be rewarded instantly
- difficulty assessing effectiveness as all patients went through token economy, and was compared to their previous behaviour rather than a control
- ethical concerns as clinicians exercise control over things that are argued to be basic rights, like eating
- behaviour may be superficial as they into engage in the behaviour to receive a token
