Schizophrenia Flashcards
(114 cards)
Outline schizophrenia
- severe mental disorder characterised by profound disruption of cognition and emotion
- This affects a person’s language, thought, perception, emotions and even their sense of self
- The schizophrenic believes things that cannot possibly be true (delusions) or hears voices or sees visions when there are no sensory stimuli to create them (hallucinations)
Describe the occurrence of schizophrenia
- experienced by around 1% of the population
- moat commonly diagnosed in men, people who love in cities, and people in lower socio-economic groups
- symptoms often interfere so severely with every day life that many end up homeless or hospitalised
Briefly outline the mechanisms of diagnosis and classification
- interlinked
- in order to diagnose specific medical disorder, we need to distinguish one from another
- we do this by identifying clusters of symptoms that occur together, and classifying this as one disorder
- diagnosis is then possible by identifying symptoms and deciding what disorder a person has
Name the two locations of criteria used for the diagnosis of schizophrenia
1) The WHO’s International Classification of Disease (ICD 10/11)
2) The American Psychiatric Associations Diagnostic and statistical manual edition 5 (DSM V)
Describe the differences between the DSM and the ICD in the diagnosis of schizophrenia
- In the DSM it is essential that the patient is experiencing at least one positive symptom to be diagnosed with schizophrenia- this is not the case in the ICD (where two or more negative symptoms would be enough)
- The ICD also has subtypes of schizophrenia such as catatonic and paranoid- These were removed from the DSM V
Outline positive symptoms of schizophrenia, name 2
Positive symptoms are those that appear to reflect an excess or distortion of normal functions- additional experiences beyond ordinary existence
- hallucinations and delusions
Outline negative symptoms of schizophrenia, name 2
- those that appear to reflect a reduction or loss of normal functions, which often persist even during periods of low (or absent) positive symptoms
- About 1 in 3 schizophrenia patients suffer from significant negative symptoms
- speed poverty and avolition
Describe hallucinations
- unusual sensory experiences
- some related to events in the environment whereas others are not connected sensory stimuli
- e.g. voices heard talking to or commenting on person, often criticising them
- can be experienced in relation to any sense
- e.g. may see distorted facial expressions or people/animals that aren’t really there
Describe delusions
- also known as paranoia
- irrational beliefs
-e.g. being important historical/religious figure - also commonly involve being persecuted, perhaps by government
- also may involve body e.g. perceiving they are under external control
- can make one behave in way that makes sense to them but seems bizarre to others
Describe speech poverty
- changes in patterns of speech- emphasis on reduction in amount and quality of speech in schizophrenia
- sometimes accompanied by delay in persons verbal responses during conversation
- modernly, more emphasis placed on speech disorganisation- speech becomes incoherent or speaker changes topic mid-sentence- this is classified in DSM as positive symptom but speech poverty is negative symptom
Describe avolition
- AKA apathy- finding it hard to begin or keep with goal-directed activity
- often have sharply reduced motivation to carry out range of activities
- Andreasen (1982)- 3 signs of avolition- poor hygiene/grooming, each of persistence in work/education, lack of energy
Describe specific elements of the DSM V diagnosis of schizophrenia
Outline what is meant by reliability in diagnosis of schizophrenia
- Diagnostic reliability means that a diagnosis of schizophrenia must be repeatable i.e. clinicians must be able to reach the same conclusions at 2 different points in time (test-retest reliability) or different clinicians must reach the same conclusions (inter-rater reliability)
Describe how schizophrenia diagnostic reliability can be assessed
- Inter-rater reliability is measured by a statistic called a kappa score
- A score of 1 indicates perfect inter-rater agreement; a score of 0 indicates zero agreement
- A kappa score of 0.7 or above is generally considered good
Describe the kappa score of schizophrenia that suggests poor reliability
Regier et al (2013)- In the DSM-V field trials
the diagnosis of schizophrenia had a kappa score of only 0.46- suggests low reliability
Describe a study of the diagnostic reliability of schizophrenia that suggests good reliability
Osorio et al (2019):
- 180 individuals using DSM V
- Pairs of interviewers achieved inter-rater reliability of +0.97 and test-retest reliability of +0.92
Name a challenge to the reliability of schizophrenia diagnosis
Cultural differences in diagnosis
Describe cultural differences in the diagnosis of schizophrenia
- Research suggests there is a significant variation between countries when it comes to diagnosing schizophrenia i.e. culture has an influence on the diagnostic process
- One of the main characteristics of schizophrenia, ‘hearing voices,’ also appears to be influenced by cultural environment- e.g. in Haiti some believe that voices are communications from ancestors
name studies surrounding cultural differences in the diagnosis of schizophrenia
- Different cultures of psychiatrist- Copeland (1971)
- Differences in symptoms- Luhrman et al (2015)
- Misrepresentation of symptoms in people with different heritages- Pinto and Jones (2008), Escobar (2012)
Describe Copeland’s study into cultural differences in the diagnosis of schizophrenia
- gave 134 US and 194 British psychiatrists a description of a patient
- 69% of the US psychiatrists diagnosed schizophrenia, but only 2% of the British ones gave the same diagnosis
Describe Luhrman’s study into cultural differences in the diagnosis of schizophrenia
- interviewed 60 adults diagnosed with schizophrenia, 20 each in Ghana, India and the US
- Each was asked about the voices they heard
- while many of the African and Indian subjects reported positive experiences with their voices, describing them as playful or offering advice, not one American did
- Rather the US subjects were more likely to report the voices they heard as violent and hateful – and indicative of being ‘sick
- Luhrman suggests that the ‘harsh, violent voices so common in the West may not be an inevitable feature of schizophrenia’
- This suggests that schizophrenia has a lack of consistent characteristics.
Describe Pinto and Jones’ /Escobar’s study into cultural differences in the diagnosis of schizophrenia
- British people of African-caribean origin are up to 9 times more likely to receive diagnosis as white British people, but people living in African-Caribean countries are not (ruling out genetic vulnerability
- suggests cultural bias in psychiatrists from different cultural background that leads to an overinterpreatation of symptoms in black Brostish people (Escobar, 2012)
Describe expectations vs reality of schizophrenia diagnosis
It was originally hoped that the use of diagnostic tools (DMS and ICD) could provide a standardised method of recognising mental disorders. However, the behaviour of an individual is always open to some interpretation. The process is actually more subjective than we hoped. The most famous study testing the subjectivity, reliability and validity of diagnostic tools was Rosenhan et al (1972).
Weaknesses of reliability in schizophrenia diagnosis
Lack of inter-rater reliability:
- Whaley (2001)- found inter-rater reliability correlations in the diagnosis of schizophrenia as low as 0.11
- Further problems with the inter-rater reliability of the diagnosis of schizophrenia are illustrated in the Rosenhan study
Unreliable symptoms:
- For a diagnosis of schizophrenia only one of the characteristic symptoms is required ‘if delusions are bizarre.
- However, this creates problems for reliability of diagnosis
- Mojtabi and Nicholson- When 50 senior psychiatrists in the US were asked to differentiate ‘bizarre’ and ‘non bizarre’ delusions, they produced inter-rater reliability correlations of only around .40
- even this central diagnostic requirement lacks sufficient reliability for it to be a reliable method of distinguishing between schizophrenia and non-schizophrenic patients
Cultural differences in prognoses:
- The prognosis for members of ethnic minority groups may actually be more positive than the majority group members
- The ethnic culture hypothesis predicts that ethnic minority groups experience less distress associated with mental disorders because of the protective characteristics and social structures that exist in most ethnic minority cultures
- Brekke and Barrio (1997)- found evidence to support this hypothesis in a study of 184 individuals with schizophrenia or a schizophrenia-spectrum disorder
- The sample was drawn from two non-white minority groups (African-Americans and Latinos) and a majority group (white Americans)
- They found that the white Americans were more symptomatic than members of the other 2 groups, findings which support the ethnic culture hypothesis