Schizophrenia Flashcards
Define schizophrenia
Schizophrenia is a serious mental disorder suffered by about 1% of the world population. It is more commonly diagnosed in men than women, in cities than the countryside and in working-class rather than middle-class people. The symptoms interfere severely with everyday tasks and so many sufferers end up homeless or hospitalised.
What are the two classification systems for schizophrenia?
The two major systems for the classification of mental disorder are the World Health Organisation’s International Classification of Disease edition 10 (ICD-10) and the American Psychiatric Association’s Diagnostic and Statistical Manual edition 5 (DSM-5).
What are the differences between the two diagnostic manuals?
They differ in their classification of schizophrenia.
The DSM-5 system requires 1 positive symptom (delusions, hallucinations, speech disorganisation).
The ICD requires 2 or more negative symptoms.
What are the subtypes of schizophrenia that the ICD-10 recognises?
ICD-10 recognises a range of subtypes of schizophrenia;
Paranoid schizophrenia - characterised by powerful delusions and hallucinations but relatively few other symptoms.
Hebephrenic schizophrenia - primarily negative symptoms.
Catatonic schizophrenia - has the defining characteristic of disturbance to movement, leaving the sufferer immobile or alternatively overactive.
Define positive symptoms.
What are the positive symptoms?
Positive symptoms of schizophrenia are additional experiences beyond those of ordinary existence.
They include:
Hallucinations - unusual sensory experiences, some are related to events in the environment whereas others bear no relationship to what the senses are picking up from the environment.
Delusions - (paranoia) irrational beliefs, can take a range of forms. Common delusions involve being an important figure or being persecuted. Other delusions concern the body. Delusions can make a sufferer of schizophrenia behave in ways that make sense to them but seem bizarre to others. The vast majority of sufferers are not aggressive and are more likely to be victims of violence, but some delusions can lead to aggression.
Disorganised speech - The DSM system emphasises speech disorganisation, where speech becomes incoherent or the speaker changes topic mid-sentence.
Define negative symptoms.
What are the negative symptoms?
Negative symptoms of schizophrenia involve the loss of usual abilities and experiences.
They include:
Avolition - finding it difficult to begin or keep up with goal-directed activity. Sufferers of schizophrenia often have sharply reduced motivation to carry out a range of activities. Andreason identified three signs of avolition; poor hygiene and grooming, lack of persistence in work or education and lack of energy.
Speech poverty (alogia) - schizophrenia reduces the amount and quality of speech, sometimes this is accompanied by a delay in the sufferer’s verbal responses during conversation. (ICD-10).
Affective flattening - a reduction in the range and intensity of emotional expression, including facial expression, voice tone, eye contact and body language.
Anhedonia - a loss of interest or pleasure in all or almost all activities, or a lack of reactivity to normally pleasurable stimuli.
Evaluate schizophrenia.
- Reliability, (consistency) to measure reliability we can assess the extent to which different assessors agree on their assessments (the extent to which two or more mental health professionals arrive at the same diagnosis for the same patients). Elie Cheniaux et al had two psychiatrists independently diagnose 100 patients using the DSM and ICD criteria. Inter-rater reliability was poor, with one diagnosing 26 with schizophrenia according to the DSM and 44 according to the ICD, and the other diagnosing 13 according to the DSM and 24 according to ICD. This poor reliability is a weakness of diagnosis of schizophrenia.
- Validity, (extent to which we are measuring what we intend to measure). To assess validity of a diagnosis we can use criterion validity, do different assessment systems arrive at the same diagnosis for the same patient? With Cheniaux’s study we can see that schizophrenia is much more likely to be diagnosed using ICD than DSM. This suggests schizophrenia is either over-diagnosed in ICD or under-diagnosed in DSM. This means there is poor validity.
- Co-morbidity, (two or more conditions occurring together), Schizophrenia is commonly diagnosed with other conditions, Buckley concluded that around half of patients also have a diagnosis of depression (50%) or substance abuse (47%). PTSD also occurred in 29% of cases and OCD in 23%. This poses a challenge for both classification and diagnosis of schizophrenia.
- Symptom overlap, there is overlap between symptoms of schizophrenia and other conditions, e.g. schizophrenia and bipolar disorder involve positive symptoms like delusions and negative symptoms like avolition. This calls in question the validity of classification and diagnosis, under ICD a patient might be diagnosed as schizophrenic however many of the same patients would be bipolar according to the DSM.
- Gender bias in diagnosis, Longenecker concluded that since the 1980s men have been diagnosed with schizophrenia more often than women. This may be because men are more genetically vulnerable to developing schizophrenia than women but there may also be gender bias in the diagnosis. Female patients typically function better than men, this may explain why some women have not been diagnosed where as men with similar symptoms might have been.
- Cultural bias in diagnosis, African Americans and English people of Afro-Caribbean origin are several times more likely than white people to be diagnosed. Rates in Africa and West Indies are not high so this is not due to genetic vulnerability, instead culture bias. An issue could be that positive symptoms such as hearing voices may be more acceptable in African cultures because of cultural beliefs in communication with ancestors. When reported these may seem bizarre and irrational. Escobar also pointed out that white psychiatrists may tend to over-interpret symptoms and distrust the honesty of black people during diagnosis.