Introduction to Schizophrenia Flashcards
a few facts about Schizophrenia?
- serious mental disorder experienced by around 1% of the world population
- more common diagnosed in men , city-dwellers and lower socio-economic groups
-symptoms can interfere with everyday tasks - so lots of people with it are hospitalised or homeless
Diagnosing and classification
according to medical approach, clusters of symptoms that occur together need to be identified to distinguish one disorder from another.
Then it is identifying the symptoms and deciding what disorder a person has.
2 major systems for the classification of mental disorders is : World Health Organisation’s International Classification of Disease and the American Psychiatric Association’s Diagnostic and Statistical Manual edition 5 - DSM-5.
they differ slightly in their classification of schizophrenia. e.g. DSM-5 system one of the ‘positive symptoms’ must be present for diagnosis whereas two or more ‘negative symptoms’ are sufficient under ICD
previous editions of ICD and DSM recognised subtypes of schizophrenia but both have dropped the subtypes as they tend to be inconsistent
what are positive symptoms
symptoms of schizophrenia that are additional experiences beyond ordinary existence - include hallucinations and delusions.
what are hallucinations?
unusual sensory experiences
- some are related to events in the environment, some have no relationship to what the senses pick up from the environment
- Hallucinations can be experiences in relation to any sense - voices heard talking to or commenting on a person, often criticising them.
what are delusions?
AKA paranoia - delusions are irrational beliefs - take a range of forms - common delusions involve being an important historical, political or religious figure.
Also include delusions of being persecuted by government or aliens or having superpowers.
another class of delusion concerns the body - a person may believe that they are under external control.
Delusions can make a person behave in ways that make sense to them but seem bizarre to others
what are negative symptoms?
involves the loss of usual abilities and experiences including speech poverty and avolition.
what is speech poverty?
Schizophrenia is characterised in changes in patterns of speech.
speech poverty - negative symptom as it emphasises reduction in the amount and quality of speech in schizophrenia.
Sometime accompanied by a delay in the person’s verbal responses during conversation
but nowadays there is more emphasis on speech disorganisation - speech is more incoherent/ speaker changes topic mid sentence . this is classified in DSM-5 as positive symptom of schizophrenia - but speech poverty remains a negative symptom.
what is avolition?
‘apathy’.
described as finding it difficult to begin or keep up with goal-directed activity e.g. actions performed in order to achieve a result.
people with schizophrenic often have sharply reduced motivation to carry out a range of activities.
Andreasen identified 3 signs of avolition - poor hygiene/ grooming, lack of persistence in work or education/ lack of energy.
Strength - Good reliability:
reliability is a measure of consistency. Psychiatric diagnosing is reliable when different diagnosing clinicians reach the same diagnosis (inter-rater reliability).
Prior to DSM-5, reliability for schizophrenia diagnosis was low but has now improved
Osorio report excellent reliability for the diagnosis of schizophrenia in 180 individuals, using the DSM-5. Pairs of interviews achieved inter-rater reliability of +97 and test re-test of +92
means we can be quite sure that the diagnosis of schizophrenia is consistently applied.
Low validity - Limitation
Limitation of the diagnosis is validity
validity- whether we assess what we are trying to assess. Criterion validity is a way to assess validity of psychiatric diagnosis.
Cheniaux had 2 psychiatrists independently assess same 100 clients using ICD-10 and DSM-IV - found that 68 were diagnosed with schizophrenia under ICD and 39 under DSM.
Suggests schizophrenia is either over-or underdiagnosed according to the diagnostic system so criterion validity is low.
counterpoint
In the Osorio study there was excellent agreement between clinicians when they used two measures to diagnose schizophrenia both derived from the DSM system.
means that the criterion validity for diagnosing schizophrenia is actually good provided it takes place within a single diagnostic system.
Co-morbidity: Limitation
L of schizophrenia diagnosis is its co-morbidity with other conditions. If conditions occur together a lot of the time, this questions the validity of their diagnosis and classification because they might actually be a single condition.
Schizophrenia is commonly diagnosed with other conditions e.g. one review found half of those diagnosed with schizophrenia also had a diagnosis of depression or substance abuse.
this is a problem for classification because it means schizophrenia may not exist as a distinct condition, and if a problem for diagnosis as at least some people diagnosed with schizophrenia may have unusual cases of conditions like depression.
reliability
the CONSISTENCY of the methods - when referring to a diagnosis using a classification system - about the consistency of the measure
inter-rater reliability - when 2 mental health professional’s agree on a diagnosis for the same patient using the same system
test re-test: when the same clinician reaches the same diagnosis for the same patient on two occasions
Validity
symptom overlap feeds into validity issues. co-morbidity is different from this - different issues which happen within the person. e.g. Schizophrenia and depression.
validity - when referring to a study it talks about whether we are measuring what we intend to
diagnostic validity - whether the classification system gives a real concept - can you really diagnose from symptoms.
criterion validity- can you predict the same illness from two different diagnostic sources - whether it is a true measure.
Limitation gender bias?
Limitation of schizophrenia is the existence of gender bias. Since 1980s, men have been diagnosed more commonly than women.
Possible explanation is that women are less vulnerable than men, perhaps because of genetic factors. But it seems more likely that women are underdiagnosed because they have closer relationships and hence get support (Cotton)
this leads to women with schizophrenia often functioning better than men
the underdiagnosis is a gender bias and means women may not be receiving treatment and services might benefit them
Limitation of schizophrenia diagnosis is the existence of culture bias.
Some symptoms of SZ - e.g. hearing voices, have different meanings in different cultures. e.g. some people in Haiti believe that voices actually are communications from ancestors
British people of Afro-Caribbean origin are up to 9 times as likely to receive a diagnosis as white British people
but living in Afro-Caribbean countries are not, ruling out genetic vulnerability
this is most likely due to culture bias in diagnosis of clients by psychiatrists from a different cultural background
this appears to lead to an overinterpretation of symptoms in black British people
this means that British African -Caribbean people may be discriminated against by a culturally biased diagnostic system
