schizophrenia Flashcards
who suggested characterising the symptoms of schizophrenia?
Kurt Schneider
what are the positive symptoms?
halluciantions
delusions
disordered thinking
define hallucinations
perceptions that are not real and are often auditory or visual and so involve seeing or hearing things that aren’t really there
define delusions
beliefs that are unreal and are usually experienced with no evidence in support of the belief
define disordered thinking
how is it often evident?
evident through examining the persons speech
the persons train of thoughts jump from one topic to the other for no apparent reason and show no logical flow of discussion (word salad)
what are the negative symptoms?
alogia
catatonic behaviour
flatness of affect
avolition
define alogia
the poverty of speech. apart from reduction in total amount of speech, it also lacks meaning and even simple, short answers can be a problem
define catatonic behaviour
issues can range widely from fast, repetitive, useless movements to little or no movement at all
define flatness of affect
where an individual would appear to have no emotion like no facial expressions
define avolition
people seem indifferent to or unconerned with their surroundings and show little desire to take part in activities that they once enjoyed
what are the requirements for a diagnosis?
2 positive and 1 negative symptom
must persist for at least 6 months with at least 1 month of active symptoms
what are the 2 biological explanations of schiz?
dopamine hypothesis
structural abnormalities
what did Griffith et al do to support the dopamine hypothesis?
- induced psychosis in non-schiz volunteers with the administration of dextro-amphetamine
- volunteers showed a generally abrupt onset of paranoid delusions and demonstrated a cold and detached emotional response
which dopamine receptor seems particularly responsive to anti-psychotic medication and where is it mainly found?
D2 found mainly in the limbic system
what does the limbic system contain?
subcortical structures like:
pituitary gland
amygdala
hypothalamus
what is the limbic system responsible for?
emotion
memory formation
arousal
what are the 2 pathways linked to schiz and where do they go to and from?
mesolimbic - from VTA to nucleus accumbens
mesocortical - from VTA to frontal lobe/pre frontal cortex
what happens in the mesolimbic pathway?
what symptoms does it lead to?
hyperactivity of D2 receptor leads to positive symptoms
what happens in the mesocortical pathway?
what symptoms does it lead to?
hypofunctionality of D1 receptor leads to negative symptoms
what is the strength of the dopamine hypothesis?
- belief that dopamine imbalances may come as a result of genetic predisposition
- Gottesman et al looked at rates of schiz in family members
- found that as genetic similarity increased, so did the risk of both individuals having schiz (1% for general pop, 50% if you have an identical twin with schiz)
what is the alternative evidence to this strength?
what does this suggest?
- the schiz working group of the psychiatric genomics consortium reported that there were 108 genetic loci associated with schiz
- this suggests that although there may be genetic basis for schiz, it appears that this complex matter involves more than a few abnormal dopamine genes
what is a weakness of the dopamine hypothesis?
(hint: contrary)
what does this suggest?
- contradictory evidence - serotonin has been identified as a potential influence
- newer atypical antipsychotics like clozapine block the D2 dopamine receptor as well as the serotonin receptor 5 - HT2A
- suggests that the action of dopamine is not sufficient to provide an exaplanation on its own - doesn’t determine the link between neurotransmission and the onzet of schiz
what is another weakness of the dopamine hypothesis?
what does this reduce?
- can’t establish cause and effect
- it could be argued that dopamine imbalances are an effect created after the onset of schiz
- Copolov and Crook researched using PET scans and they haven’t yet been able to detect differences in the dopamine activity of those who have schiz and those who don’t
- this reduces the validity of this hypothesis which has huge implications for this explanation
what is another weakness of the dopamine hypothesis?
(hint: method)
what does this suggest?
- concerns over methodological processes
- it’s very difficult to make direct measurements of dopamine so most of the research exploring dopamine action is based upon metabolites
- metabolites can be assessed in cerebrospinal fluid
- dopamine is broken down into HVA which is also measured in the cerebrospinal fluid as opposed to measuring levels of dopamine itself
- therefore we should adopt an element of caution as the research may be based on metabolite levels instead of dopamine
briefly explain how biological explanations could be applied to MOM schiz? (5)
- schizos produce excessive amounts of dopamine
- to reduce suffering and symptoms like hallucinations and delusions - lower dopamine levels
- antipsychotics work by binding to but not stimulating the receptors preventing dopamine from gaining access
- dopamine levels reduce - can cause side effects
- new atypical antipsychotics bind to receptors but rapidly dissociate - allows for some transmission and side effects are lessened
what are the 3 sections to structural abnormalities?
- englarged ventricles
- cortical atrophy
- reversed cerebral asymmetry
what are ventricles?
cavities that produce and transport cerebrospinal fluid
enlarged ventricles
- research
- lead to schiz?
- Andreasen studied MRI scans of individuals with or wothout schiz and found that those with schiz had ventricles that were 20-50% larger than the others
- connections between neurons gets disrupted as ventricles enlarge whcih can lead to a lack of chemical stability in the brain - leads to abnormal functioning
what is cortical atrophy?
the loss of neurons in the cerebral cortex. it affects the cognitive functions of that area
cortical atrophy
- research
- how can it lead to increased ventricle size?
- Vita et al ised CAT scans to assess 143 indivudals with schiz and 45 without - found that 33% of those with schiz showed moderate to severe atrophy
- as the volume of the brain decreases, cerebrospinal fluid replaces brain matter and puts pressure on the ventricles whcih enlarges them
reversed cerebral asymmetry
in many schizos the right hemisphere is larger than the left which is reversed in non schizo brains. as language function is located on the left hemisphere, the reversed asymmetry may account for some of the symptoms such as alogia
what is the strength of structural abnormalities?
what does this suggest?
- findings from the studies are highly reliable
- McCarley et al suggested that the presence of enlarged ventricles is the most reliable finding in research using brain scans
- Flashman and Green have confirmed the link between schiz and cortical atrophy
- McCarley et al also suggested that factors like age, sex and severity of symptoms can all have an influence on the observed brain abnormalities
- suggests that either structural abnormalities are only evident in some schizos or that we need to acknowledge more subtle differences when assessing these abnormalities
what is the weakness of structural abnormailites?
what does this do and suggest as a result?
- the structural abnormalities can be found in individuals suffering from other conditions than schiz
- Roy et al noted that people diagnosed with bipolar disorder and schizoaffective disorder also have enlarged ventricles
- similarly, these abnormalities are not found in all schizos
- this weaknes the validity and suggests that we need to consider other factors that may account for the illness
what are the 2 individual difference explanations of schiz?
cognitive explanation
schizophrenogenic mother
what does the cognitive approach view behaviour and thoughts as being a product of?
what is it about this that is said to cause schiz?
internal mental processes
if one or all of these are faulty
what are the 5 internal mental processes?
cognition
memory
language
perception
attention
what is the Theory of Mind?
developing a sense of what other are thinking to help to form our response
what is the positive symptom linked to the cognitive explanation?
hallucinations
what did Morrison propose about hallucinations?
that they can be onset by a variety of triggers including stress, lack of sleep and certain drugs. the people that have migraine and vision problems but no other symptoms of schiz do not recieve a diagnosis. those experiencing hallucinations may appraise these voices inappropriately whcih elicits behaviours like social withdrawal
what was Frith’s theory (1992) about schizos hearing voices?
we have an ‘inner voice’ and we use it to think. he argues that schizos can’t monitor their own thoughts, misattributing them to the outside world, so when a person hears voices it’s just their inner speech being misinterpreted
what is McGuire’s theory that supports Frith?
what did other research show linking to this?
he found that schizos have reduced activity in those parts of the brain involved in monitoring speech
other research used PET scans and found an under-activity in the frontal lobe of schizos which is linked to self-monitoring
who applied their theory to the negative symptoms? what was this theory? what are the 3 parts to it?
Beck’s cognitive triad
the future
the self
the world
how did he explain these symptoms:
alogia
avolition
flatness of affect
catatonic behaviour
believe they have nothing valuable to say
loss of self confidence - nobody likes them
negative thoughts = unemotional
negative view of self leads to tics (nervous). depression = lack of movement
what are schizos said to have a lack of?
cognitive explanation
preconscious filters
what are preconscious filters?
all the informatio from our environment enters our preconscious where thought occurs without awareness. the information that our brain interprets as the most pertinenet enters the conscious mind and the rest is filtered out
what did Frith (1979) propose about schizophrenics in relation to preconscious filters?
that the attentional filters that inhibit most of the sensory information from making it into our conscious are defective. so things that are usually filtered out as irrevelant are now more significant than they really are
what did Frith say the cognitive deficits are caused by?
what did research show?
abnormalities in those areas of the brain that uses dopamine, especially the prefrontal cortex.
research shows schizos have reduced blood flow to these areas during certain cogntive tasks
what symptoms can the lack of preconscious filters account for and why?
hallucinations, delusions and disorganized speech
the inability to properly focus causes schizophrenics to give the impression of disordered thought
what did Bentall argue?
what could this explain?
that schizos have attentional bias towards stimuli of a threatening and emotional nature, particularly stimuli associated with violence and pain. they are also more leikly to percieve stimuli as threatening when it isn’t
paranoid delusions
what is the strength of the cognitive explanation?
that does this suggest?
- research evidence
- Barch et al compared performance on a stroop test between schizos and non schizos
- those with schiz were slower and made more mistakes
- this is evidence that they can’t filter the information as effectively
- suggests that evidence has been produced to support Frith’s idea that the attentional filters of schizos are defective
what is the peanut butter to the strength of the cognitive explanation?
question validity of the use of stroop test to measure cognitive abilities as it’s difficult for everyone
what is one weakness of the cognitive explanation?
(hint: simplified)
- reductionist
- Frith proposed there the faulty operation of cognitive mechanisms is due to impairment within the frontal cortex and posterior areas of the brain
- despite this, it’s almost impossible to imagine that schiz will come down to mere functioning of a few brain circuits
what is another weakness of the cognitive explanation?
(hint: not accountable)
what does this suggest?
- only accounts for the cognitive based symptoms
- fails to account for origins of cognitive deficits that result in schiz
- this explantion can only explain proximal causes not distal causes
- suggests that we should be cautious about claims made by this approach as a single explanation for schiz
what is another weakness of the cognitive explanation?
(hint: holistic)
what does this demonstrate?
- needs to be considered in a more holistic way
- Howes and Murray proposed that genes or other factors in early life combined with difficult life events or social stressors provokes the realease of dopamine
- this causes problems with cognitive processing especially hallucinations and delusions
- the individula gets caught in a cycle due to stress and it prompts the release of more dopamine
- demonstrates that this explanantion if insufficient alone but can be used in conjunction with other theories
briefly explain how the cognitive explanation could be applied to the MOM schiz
- a major symptom of schiz is seen in the disordered thinking of an individual, possibly cause by faulty information processing recieved from the environment
- the purpose of CBT is to help an idividual help and organise their disordered thoughts in a more rational way
- CBT helps them to realise that their disordered thinking is likely the cause of their illness
- CBT sessions are collabrative between the client and the therapist over a number of sessions using disputing techniques to challenge their perception
- they also work on relapse preventing strategies where early warning signs of relapse are identified and plans can be developed
what can cause regression to an earlier stage?
explain in terms of the oral stage
stress or trauma
id is overly dominant = creation of alternate realities/delusions
what is the Lidz and Lidz research in terms of the schizophrenogenic mother?
a number of studies suggested that the mother-child relationship was disordered in cases where the child was schizophrenic
what did Fromm-Reichmann suggest?
- that the trigger for schiz came from mothers who were overly dominant in the home and dominant in their interactions with the schizo child
- however while being controlling and overprotective, they were also cold and distant
- the overprotection stifles the child’s development and leaves the child feeling emotionally insecure
what is the strength of the schizophrenogenic mother?
what does this suggest?
- explanatory power that Freud’s theories have
- provides explanation as to why schizos lose touch with reality and he argues that schizo is a regression to an infant like state - links with many of the symptoms
- due to a wide range of symptoms it’s unable to account for all cases
- suggests that Freud may have some insight into the reason as to why schiz develops but may at best only be able to offer a partial explanation
what is the weakness of the schizophrenogenic mother?
- concepts are out of date and widely discredited by today’s psychologists
- in not being able to verify the existence of concepts like the id, ego and the superego or defence mechanisms, it becomes almost impossible to trust in and accept a psychodynamic approach
- so if the concepts of Freud’s theory of schiz is founded on no basis, it reduces the validity of the whole explanation
what are the 2 social psychological explanations of schizophrenia?
dysfunctional families
sociocultural factors
what are the 2 explanations within dysfunctional families?
double bind theory
expressed emotion
who proposed the double bind theory?
what is it?
Bateson
conflicting messages - if a child is repeatedly exposed to social interactions with 2 conflicting messages and the child doesn’t get an opportunity to ignore them or respond to them they may develop schizophrenia
e.g. parent asks how your day was whilst on their phone
what is paralanguage and how is it related to double bind statements?
non verbal cues - body language, tone of voice, facial expression
words may not match paralanguage shown by parent so the child is getting 2 contradicting messages and whatever their actions, they can’t win
how might exposure to double bind statements lead to behaviours seen in schizophrenia?
delusions
avolition
flatness of affect
delusions - false beliefs through hidden meanings
avolition - avoid social interactions for emotional safety
flatness of affect - learned not to demonstrate emotion
what was the research involved with discovering expressed emotion?
Brown - investigated 156 men with schiz after being discharged from hospital; found that those who stay with their partner or wives were more likely to relapse than those in lodgings or with siblings - fund a relationship between the amount of expressed emotion within a household and the likelihood of relapse
what are the 3 main complements of expressed emotion?
critical comments
hostility
emotional over involvement
what are critical comments and give an example
making comments which are critical of a persons behaviour, appearance or anything about them
e.g. ‘you’re always so negative’ ; ‘why can’t you be more like ____’
what is emotional over involvement and give an example
being too invested or involved in another persons life to the point where emotions become enmeshed
e.g always asking how they are; excessive blame/praise; asking too personal questions
what is hostility and give an example
being openly rude and unkind - showing distaste or dislike
e.g ‘you’re stupid’ ; ‘I hate you’
what is the strength of dysfunctional families?
- supportive evidence
- Vaughn and Leff offered support for the role of EE in relapse rates
- found 53% of those with schiz who had high EE relapsed within 9 months; 12% of those with low EE relapsed
- however, McCreadie and Philips failed to find higher 6 and 12 month relapse rates among those with schiz living in a high EE home
- suggests that although EE may be a significant factor in relapse rates it is not the only and doesn’t appear to cause the onset of schiz
what is a weakness of dysfunctional families?
(double bind theory)
- findings have been inconclusive in regards to the double bind theory
- Liam suggested that the difference found in the parental communications may just be parents adjusting their communication styles to deal with a schiz child
- suggests that the communication difficulties that the theory is based on may really be an effect not a cause of schiz
what is another weakness of dysfunctional families?
(definition of double bind)
- determining what classes as a double bind statement if very subjective
- Ringuette and Kennedy discovered that the so called experts in the theory were no better at identifying double bind statements than the non experts
- suggest that due to the fact that we can’t define double bind, it also can’t be measured of its effect on schiz
what is another weakness of dysfunctional families?
(genes)
- schiz could equally be due to the product of family shared genes as much as communication difficulties
- Gottesman et al found that as genetic similarity increased so did the probability of both individuals having schiz
- looking at the Diathesis Stress Model - genetics may predispose someone to schiz and family relationships may act as a psychological trigger and cause the onset
- suggests that an interactionist biopsychological explanation may be required
briefly explain how social psychological explanations could be applied to MOM schizophrenia [5]
- the dysfunctional families explanation suggest the disorder is cause by communication difficulties within the family home
- it is suggested that a significant reduction in relapse rates can be achieve through family based interventions rather than working in isolation with the individual with schiz
- Pharaoh et al revised 53 randomised controlled trials that concluded that family interventions decreased both frequency of relapse and reduced hospital admissions
- family based interventions could include; increase ability of family members to solve and anticipate problems; reduce expressions of anger and guilt; maintain reasonable expectations for how the ill family member should perform
what are the 3 sociocultural factors?
urbanicity
social isolation
ethnicity and discrimination
Faris and Dunham - urbanicity
findings from their investigation of schizophrenia in Chicago demonstrated there was a higher incidence of schiz in densely population centre of the city rather than the less densely populated suburbs
Krabbendam and van Os - urbanicity
features of urban environment that might be inclined towards the development of schizophrenia characteristics
- poverty
- environmental pollution
- overcrowding
- drug abuse
