sz Flashcards
brief summary of sz
Schizophrenia is the most common psychotic disorder, affecting around 1% of the population. It is often diagnosed between 15 and 35, with men and women equally affected. The symptoms are typically divided into positive and negative. To be diagnosed, 2 or more symptoms must be apparent for 1 month, as well as reduced social functioning. Type 1 schizophrenia is characterized by positive symptoms which are symptoms that reflect excess or distortion of reality.
what type of symptoms is type 1 associated with?
positive
explain some positive symptoms?
Hallucinations – unreal perceptions of the environment which are usually auditory ( hearing voices that other people cant hear but may also be visual seeing lights, objects or faces that other people cant see olfactory smelling thins that other people cant smell or tactile feeling bugs that are crawling under the skin Many SZs also report hearing voices telling them to do something.
Delusions - Firmly held erroneous beliefs that are caused by distortions of reasoning or misinterpretations of perceptions
what type of symptoms is type 2 associated with?
Type 2 schizophrenia is characterized by negative symptoms and generally has poorer prospects for recovery.
They weaken the person’s ability to cope with everyday functioning due to loss of usual abilities and experiences.
explain some negative symptoms?
Speech poverty - Distortions or exaggerations of perception in any of the senses, most notably auditory. The character signs are producing fewer words in a given time on verbal fluency tasks, and also using less complex syntax e.g shorter utterances
Avolition - Firmly held erroneous beliefs that are caused by distortions of reasoning or misinterpretations of perceptions e.g sitting in the house for hours a day doing nothing. It is a reduction in self-initiated activities that are available to them, rather than disinterest which may be due to having no social contact with family and friends because they have none.
Anhedonia – loss of interest or pleasure in all/almost all activities. E.g physical anhedonia (no pleasure from food, bodily contact), or social anhedonia (inability to experience pleasure from interacting with others.
Affective Flattering – reduced range of emotional expression, e.g facial expression, voice tone, eye contact
explain the two types of reliability for SZ
Reliability – concerns the consistency of symptom measurement and can affect diagnosis in 2 ways
Test – retest reliability – Be able to produce the same results from multiple consecutive tests for schizophrenia
Inter-rater reliability - Two or more different clinicians are making the same diagnosis of the same patient
evaluate reliability of SZ? and studies to evaluate with?
Becker et al (1961)
Looked at the inter-rater reliability between two psychiatrists when considering diagnoses for 154 patients.
Reliability was only 54% - they agreed on diagnoses for 54% of the 154 patients.
Therefore inter-rate reliability using the DSM is low as the clinicians are only agreeing on around 50%
HOWEVER inter rater reliability has gone up
Soderberg et al (2005) reported concordance of 81% with DSM
probably to do with the fact the classification systems have been updated - we are on DSM 5
inter-rater reliability has gone up
BUT Nilsson et al. (2000) only 60% concordance with ICD classification, implying
ICD appears to have worse inter-rater reliability and there seems to be differences within the classification systems
what are the classification systems of mental disorders?
Mental disorders are diagnosed by reference to a classification system, where a group of symptoms can be classed together as a syndrome.
The 2 commonly used ones are the DSM-5 (USA) and ICD-10 (WHO)
study that suggests SZ is as a result of environmental causes?
Keith et al (1991)
Looked at social class bias The percentages of those diagnosed with schizophrenia in: Lower class: 1.9% Middle class: 0.9% Upper class: 0.4%
Johnstone claimed the lower class tend to be diagnosed more with severe disorders than middle class people with very similar symptoms.
Schizophrenia could be as a result of environmental causes
This could be because psychiatrists tend to be white and middle to upper class. They may not understand the behaviour of the lower social class patients, which leads to a problem of reliability.
what are the different types of validity for sz?
Predictive Validity – if diagnosis leads to successful treatment, then diagnosis is valid
Descriptive validity – to be valid, patients with SZ should differ in symptoms from patients with other disorders
Aetiological validity – to be valid, all SZs should have the same cause of the disorder
study into descriptive validity of SZ?
Rosenhan (1973) He arranged for ‘pseudopatients’ to present themselves to psychiatric hospitals claiming to be hearing voices (a symptom of schizophrenia). All were diagnosed with schizophrenia and admitted, despite the fact they displayed no further symptoms during their hospitalisation. Throughout their stay, none of the staff recognised that they were actually normal. They remained in hospital for an average of 19 days (ranging from 7-52 days!)
Behaviour was interpreted to meet expectations. Sanity was not recognized.
This shows that the diagnosis for SZ has problems with descriptive validity because professionals cannot recognize the difference between a genuine symptom of schizophrenia and someone who is claiming to have one.
Implications:
Legal – not guilty or guilty
Economic implications – allocation of resources
describe the problem of co-morbidity and SZ? what study supports this?
Differentiating schizophrenia from other disorders is not always easy. This is particularly the case as patients may have more than one disorder which co-occur (co-morbidity). For example, schizophrenia and depression are often found together. This affects the descriptive validity of classifying and diagnosing schizophrenia because it is hard to tell how ‘real’ and distinct an individual mental illness is.
Sim et al. (2006) reported 32% of 142 hosptialised SZs had an additional mental disorder
These findings suggest that there will be a problem with diagnosing schizophrenia- due to poor descriptive validity
Depression/schizophrenia - hard to differentiate between symptoms
Implications – need to figure out what disorder the person has before you can treat it
explain cultural bias of SZ? study to support this?
Culture bias refers to the tendancy to over diagnose members of other cultures as suffering from SZ. In Britain, people from Afro-Carribean descent are much more likely than white people to be diagnosed, and in addition psychiatrists are more likely to perceive them as being dangerous. One issue is that positive symptoms such as auditory hallucinations may be more acceptable in African cultures, and thus people are more ready to acknowledge such experiences
McGovern and Cope (1977) reported that 2 thirds of patients in Birmingham hospitals were first and second generation Afro-Carribeans, the other 3rd being white and Asian
Problem with reliability because there is no reason as to why afro Caribbean’s are more likely to have schizophrenia
This could be as a result of ethnocentrism or imposed etic
However this could be as a result of how in 1997 there may have been racism, this could be an explanation for the racial bias
explain gender bias in terms of SZ? study to support this?
Gender bias occurs in diagnosis, as men are more likely to be diagnosed than women, despite the belief that males and females are equally vulnerable. It appears that female patients typically function better than men, being more likely to work and have good family relationships (Cotton et al. 2009), this may explain why may not be diagnosed even where they have similar symptoms to men.
Loring and Powell (1988) randomly selected male and female psychiatrists to review patient cases. When patients were described as male, 56% of psychiatrists gave a diagnosis of SZ, whereas when described as female, 20% were given a diagnosis
Because we are being inconsistent with diagnosing men and women this is a problem with reliability.
BUT gender bias was not as evident amongst female psychiatrists , suggesting that the diagnosis is influenced not only by the gender of the patient but also the gender of the clinician.
This suggests that there I bias within psychiatrists
explain the overlap of symptoms and SZ and study to evaluate? use examples
There is an overlap between the symptoms of SZ and other conditions. Where conditions share many symptoms, this questions the validity of classifying to 2 disorders separately. E.g SZ and bipolar involve similar symptoms such as delusions and descriptive symptoms such as avolition. Symptom overlap can also occur with autism and cocaine intoxification.
Serper et al. (1999) assessed patients with co-morbid SZ and cocaine abuse, cocaine intoxification on its own and SZ on its own. They found that although there is in symptoms, it was possible to make accurate diagnoses.
Social anhedonia symptom overlap between schizophrenia and autism
symptom delusions overlap between schizophrenia and cocaine use.
