paper 3 - Schizophrenia Flashcards
(40 cards)
Clinical characteristics of sz
Two main types of symptoms:
Positive = excess of normal functioning
Negative = loss of normal functioning
Positive symptoms - delusions
Bizarre beliefs that seem real to the person with sz
Delusions of persecution = the belief they are being watched/ followed
Delusions of grandeur = the belief they are in a prominent position of power over others of have special powers
Positive symptoms - hallucinations
Bizarre, unreal perceptions of the environment
Auditory = hearing voices
Visual = seeing lights / objects
Olfactory= smelling things
Tactile = feeling bugs on your skin
Positive symptoms - disorganised thinking and speech
Neologisms = made up words with no meaning e.g. glump
Word salad = speech is jumbled up and incoherent
Clang = putting words that rhyme or sound similar together even though they mean different things
Negative symptoms - alogia
Poverty of speech
Reduction in the amount and quality of speech
Negative symptoms - avolition
A reduction of interests and desires as well as the inability to initiate and persist in goal directed behaviour e.g. sitting in the house all day doing nothing
Issues with validity of classification and diagnosis of sz
Gender bias = diagnostic criteria may be biased towards one gender, clinicians may base their diagnosis on stereotypical beliefs
Symptom overlap = some symptoms of sz can be found in other disorders such as depression this makes it difficult to accurately distinguish sz from other disorders in diagnosis
Comorbidity = two or more conditions can occur at the same time this creates difficulties in diagnosis and deciding on a treatment pathway
evaluation of issues of validity
- evidence for gender bias comes from loring and powell. When psychiatrists were given cases to diagnose for sz, males had a 56% diagnosis and females only 20%. This shows evidence of gender bias.
- evidence for symptom overlap comes from ellason and Ross. Found that people with dissociative identity disorder have a larger amount of sz symptoms than sz patients have
This is an issue as it questions whether these disorder are separate - evidence for co morbidity comes from buckeley. Comorbid depression occurs in 50% of patients and 47% have a diagnosis of cormoibid substance abuse. There is a significant overlap between disorders
Issues with reliability of classification and diagnosis of sz
Culture bias = psychiatrists are influenced by their own cultures values and expectations when diagnosing patients. What is seen as bizarre in one culture might be normal in another, this leads to inconsistent diagnosis.
Evaluation of issues of validity
- inter observer reliability. When British and American psychiatrists were given a description of a patient for diagnosis 69% American diagnosed sz but only 2% British. Diagnosis has low inter observer reliability
- patients from certain cultural groups are more likely to be diagnosed than others. African Caribbean groups are 8 times for likely to be diagnosed than white groups in the uk. Psychiatrists may be misinterpreting cultural differences, ethnocentric bias
Biological explanation of sz - genetic
Sz is passed on from one generation to the next through genetic inheritance
The more closely related the family member is to the person with sz the more likely they will develop the disorder
Sz is polygenic - no one gene causes it, it is caused by multiple genes
Evidence for the genetic explanation
Family studies, twin studies and adoption studies
Used to establish a concordance rate or the degree to which the relatives share the same disorder
E.g. mz twins and dz twins where one of each twin pair has sz can be compared to see how often the other twin shows the illness
If sz is genetic it is argued that mz twins have a higher concordance rate for the disorder than dz twins
Evaluation of the genetic explanation
+ family studies. 16% of first degree relatives of sz patients contracted sz compared to 7% controls. The more genetically related you are the more likely you will develop the disorder.
However the increeased rate of sz could be due to environmental factors
+ twin studies. Concordance rate of 40% for mz twins compared to 7% dz twins. Likely to be genetic. However concordance rate not 100% in mz so must be other explanations
+ adoption studies. Compared adopted children with biological mother with sz compared to control group. Higher rate of sz with those with sz mother. When the environmental risk of sz mother was removed they still developed the disorder. However, healthy adoptive families can protect against high genetic risk.
Biological explanation of sz - neural correlates
The experience of mental illness is associated with abnormalities to the structure of function of the brain.
Enlarged ventricles are associated with damage to the central brain and pre frontal cortex which has been linked to sz
The dopamine hypothesis suggests that positive symptoms of sz are a result of overactive transmission of dopamine. Sz thought to have high numbers of d2 receptors on receiving neurons resulting in more dopamine binding and more neurons firing, leading to issues with attention perception and thought processes
The revised dopamine hypothesis
Davis and Kahn
Positive symptoms are caused by an excess of dopamine in the sub cortical areas of the brain ( mesolimbic pathway ). Negative symptoms are thought to arise from a deficit of dopamine in areas of the pre-frontal cortex ( mesocortical pathway).
Positive evaluation of dopamine hypothesis
+ drug research. Amphetamine drugs are agonists which stimulate neurons containing dopamine causing the synapse to be flooded. Large doses of these drugs have been found to cause hallucinations and delusions.
+ the drug L dopa which is used to treat Parkinson’s disease which also works by raising dopamine levels. Could explain the link to positive symptoms of sz
+ practical applications. Antipsychotic drugs used to treat sz are dopamine agonists. They reduce stimulation of neurons containing dopamine by blocking D2 receptors reducing positive symptoms of sz. Shows dopamine hypothesis is useful.
Negative evaluation of dopamine hypothesis
- newer antipsychotic drugs ( atypical antipsychotics ) only temporarily block dopamine receptors whilst also blocking serotonin receptors and these drugs have been shown to be more effective than typical antipsychotics. The dopamine hypothesis is too simplistic as other neurotransmitters may also be implicated in development of sz
- a problem with neural correlates is that cause and effect is unclear. Brain abnormalities could be the effect rather than the cause of sz. It could be symptoms that cause changes in brain function. We do not fully understand the role of neural correlates for sz
- determinist. Sz caused by factors outside of our control. If they feel they have no control over developing the disorder they may engage in risky behaviour e.g. substance abuse
- reductionist. Focus wholly on internal factors and ignore environmental factors
Psychological explanations of sz- family dysfunction
Family dysfunction explanations claim that the risk of sz is increased when there are abnormal patterns of communication within the family
Double blind theory
Schizophrenic mother
Expressed emotion
Double blind theory
Bateson et al suggested that children who receive contradictory messages from their parents are more likely to develop sz e.g. if a mother tells her son she loves him yet at the same time turns her head away in disgust. These contradictions means the child regularly feels trapped in situations where they fear doing the wrong thing but receive mixed messages about how to think or behave. This leaves the child with an understanding of the world as confusing and dangerous and this is later reflected in symptoms such as paranoid delusions.
Schizophrenic mother
Freida Fromm-reichmann found that many patients who were asked about their childhood described a mother who was cold, rejecting, controlling and an atmosphere in the home characterised by tension and secrecy. This leads to distrust which can cause paranoid delusions
Expressed emotion
EE refers to the level of emotion expressed towards a sz sufferer by their family. It can be shown in different ways including: verbal criticism of the patient and hostility towards them, including anger and rejection
Emotional over involvement in the life of the patient including needless self sacrifice
EE has been primarily linked to the course of the disorder rather than seen as the cause. High levels of EE in caters have been found to lead to poorer outcomes and an increased likelihood of relapse and a return of psychotic experiences for the patient
Evaluation of family dysfunction
+ Berger found that szs reported higher recall of double blind statements form their mothers than non szs. This suggests contradictory messages during upbringing may increase the risk of sz in later life
+ furthermore support for the role of EE comes from tienari et al who assessed a group of adopted children whose biological other had sz compared to a control group with no genetic risk. He found that when the parenting style of the adoptive family was characterised as highly critical with low levels of empathy this increased the risk of sz but those in a healthy adoptive family had a protective effect of those with high genetic risk. Suggesting EE in families can increase the risk of sz but also low EE can help
+ practical applications, led researchers to develop family therapy to increase the patients chances of recovery and decrease chances of relapse. Relapse rate in family therapy condition was 26% compared to 50% relapse in control group receiving standard care. Family dysfunction theories have led to psychological therapies that benefit people’s lives
+ dysfunctional events within family may be a risk factor of sz. 69% of female szs had a history of physical or sexual abuse and 59% of male szs. Family dysfunction in the form of abuse may be a risk factor for the development of schizophrenic symptoms in future.
Cognitive explanations for sz- dysfunctional thought processing
Cognitive explanations argue that the symptoms are a result of dysfunctional thought processing. Sufferers process information differently to those without the disorder. Specific symptoms can be linked to disruption of specific cognitive processes.
- egocentric bias
- central control
Egocentric bias
Cognitive bias that causes people to rely to heavily on their own point of view when they examine events in their life or when they try to see things from other peoples perspective. It causes people to either underestimate how different other peoples viewpoint is from their own or to ignore other people viewpoint entirely. Sufferers interpret external events as having personal significance to them or it being their fault and arrive at false conclusions
E.g. if you do something embarrassing the egocentric bias can cause you to overstimulate the degree to which other people are likely to notice it because it can cause you to assume that others are as focused on your actions as you are. This can lead to paranoia, delusions and hallucinations
