Y2 Chapter 8 Schizophrenia Flashcards
Outline what schizophrenia is and who it affects
- Schizophrenia is a serious mental illness and affects about 1% of the population
- It distorts contact with reality and impairs the persons insight
- It is more common in men than women and is more commonly seen in working class than middle class
Define what’s meant by a negative symptom of schizophrenia
- A negative symptom of schizophrenia is where there is a loss in ability or control
- For example, avolition or apathy where the sufferers struggle to keep up with goal oriented behaviour
- Andreason (1982) identified three signs of avolition; poor hygiene, lack of persistence in work or education and lack of energy
- Another negative symptom is speech poverty which is the reduction in the quantity and quality of speech
Define what’s meant by a positive symptom of schizophrenia
- A positive symptom refers to the addition of an experience
- For example, hallucination or delusions
- Hallucinations refer to unusual sensory experiences that can be pick up by any senses
- Sometimes they relate to the environment sometimes they don’t
- Delusions refer to irrational beliefs and come in a variety of forms
- Paranoia, grandeur, external control
What is meant by the DSM-V and the IDC-10 and how do they differ in their classification of schizophrenia
- The DSM-V in the American psychiatric association’s diagnostic and statistical manual edition 5 which uses positive symptoms
- One or more positive symptoms must be present to give a diagnosis- The IDC-10 is the World Health Organization’s international classification of disease edition 10
- This requires two or more negative symptoms to be diagnosed
- Also recognises different types of schizophrenia
Outline the weakness and limitations of diagnosis of schizophrenia
-Issues of reliability in the diagnosis
-Cheniaux et al. Had two psychiatrists independently diagnose 100 patients using both the DSM and ICD criteria
- inter-rater reliability was poor
-One diagnosed 26 using the DSM and 44 with the ICD; the other 13 and 24
- inconsistency is a limitation
-Issues with the validity of diagnosis
-Cheniaux et al showed that schizophrenia is more likely to be diagnosed with the ICD. This means the either the ICD over-diagnoses or the DSM under-diagnoses
-Comorbility
-Two or more conditions can occur together. Calls into question whether they are a single condition
-Bickley et al. 50% of people with schizophrenia had depression and 47% suffer from substance abuse
-If severe depression looks like schizophrenia they could be confused and maybe they should be seen as one condition
-Symptom overlap
-There is considerable overlap of symptoms of schizophrenia and other conditions such as bi-polar
-Calls into question the validity of diagnosis
-Patients would be classed as bi-polar under DSM
and schizophrenic under ICD
Is diagnosis of schizophrenia culture bias, if so explain why
- African-american and british people of African origin are more likely to be diagnosed with schizophrenia in the uk
- Rates in the west indies and west africa are not so high. Some symptoms are classed as normal behaviour in west africa
- This is culture bias as people from certain backgrounds are more likely to be diagnosed with schizophrenia
Outline one biological explanation for schizophrenia
- Dopamine appears to be involved in many of the systems implicated in the symptoms of schizophrenia
- The original theory focuses on excess dopamine in the sub cortex e.g. Broca’s area
- More recent theory focus on abnormal dopamine levels as it has been found that low levels of dopamine as the cause for many of the negative symptoms
- Possibly both hyper and hypodopaminergia are involved in schizophrenia
Describe what is meant by neural correlates - use examples to illustrate your answer
- Patterns of structure or activity found in the brain that occur in conjunction with symptoms
- Juckel et al - found that reduced activity in the ventral striatum was associated with avolition
- This area is responsible for the anticipation of reward, which create motivation
- Without motivation people won’t engage in goal directed behaviour
Outline a piece of supporting evidence for biological explanations of schizophrenia
- Gottesmean family study showed the close relationship between genetic similarity and shared risk of schizophrenia
- Adoption, family and genetic linkage studies all point towards a role of genetics in vulnerability to schizophrenia
- Tienari et al - schizophrenia may not be entirely genetic but there is lots of evidence to suggest that genetic factors contribute to vulnerability
Outline some weaknesses of biological explanations for schizophrenia
- Mixed support for the dopamine hypothesis
- Support - Dopamine antagonists can make symptoms of schizophrenia worse, antipsychotics are dopamine antagonists
- Some of the genes associated with schizophrenia code for entirely different chemical e.g. glutamate
- This means the dopamine cannot provide a complete explanation for schizophrenia- Correlation vs causation
- Neural correlates are just correlates
- e.g. negative symptoms may be cause by reduced activity in the ventral striatum or the low activity is the result of low information processing due to an unknown third factor
- Correlates tell us little about the cause of schizophrenia
- Environment is clearly involved
- The probability of developing schizophrenia is only about 50% even for identical twins
- Evidence shows that family factors could also play a role in the development of schizophrenia
- Schizophrenia may be a result of a combination of biological and environmental factors
- Correlation vs causation
Explain how family dysfunction might be involved in schizophrenia. Refer to two or more types of family dysfunction in your answer
- Schizophrenogenic mother
- Cold, rejecting and controlling
- Environment of secrecy and tension
- Can lead to distrust and paranoid delusions- Double blinds
- Role of communication
- Child receives mixed messages about what to do and trapped in situations where they fear doing the wrong thing
- Can’t ask for clarification
- Punished through withdrawal of love
- Leads to a view of the world as a confusing and dangerous place
- Expressed emotion
- Communication and negative towards the patient from their carers
- verbal criticism, hostility, anger, rejection and over-involvement in life of patients
- Serious source of stress - primary source of relapse
- Double blinds
Outline at least two ways in which a cognitive psychologist might explain schizophrenia
- Poor metarepresentation
- Metarepresentation is the ability to reflect on thought and behaviour
- insight into interactions and goals allows us to interpret actions of others
- People with schizophrenia have an inability to recognise their actions as being their own- Poor central control
- People with schizophrenia have an inability to suppress automatic reactions while they perform deliberate ones
- Disorganised speach
- They also have an inability to suppress automatic thoughts associated with other thoughts
- Poor central control
Outline a supporting study for dysfunctional thought processing
- Stirling et al
- Compared 30 patients with schizophrenia to a control group on cognitive tasks
- Patients with schizophrenia took longer to complete the stoop test
- Shows cognitive impairment
- Supports the theory of central control dysfunction
- However, a downside of cognitive explanations is that they tell us nothing about the origin of symptoms
Evaluate psychological explanations for schizophrenia
- Research into the role of the family
- A large proportion of patients report childhood sexual abuse (Read et al) or insecure attachment (Berry et al)
- Supports the link between upbringing and schizophrenia
- However, the evidence is retrospective
- Symptoms could distort recall
- therefor the research lack validity- Evidence for family based explanations is weak
- Little to no evidence for schizophrenogenic mother or double-bind hypothesis
- In addition, family based explanations may encourage the blaming of the parents whose children develop schizophrenia
- Undermines the appropriateness and credibility of the explanation
- Direction of causality
- It remains unclear whether cognitive aspects are a cause or a result of neural correlates and abnormal neurotransmitter levels
- Evidence for family based explanations is weak
What is meant by typical antipsychotics?
- E.g. chlorpromazine
- Work by acting as antagonists in the dopamine system –>aims to reduce the action of dopamine
- Works by blocking the dopamine receptors in the synapses
- Initially the dopamine levels build up to make up for the deficit, but then production is reduced
- This normalises neurotransmission in the brain, which reduces positive symptoms
- Also has a sedation effect , useful in anxious patients
