Classification of Sz + Reliability and Validity in diagnosis and classification Flashcards
Key Words
Schizophrenia - A mental disorder which is characterised by a profound disruption of cognition and emotion, which affects language, thought, perception and sense of self. NOT split mind, this is where your mind is disassociated from reality.
Avolition - Extreme apathy, lack of energy, a loss of interest and passion. Finding it difficult to begin and keep up with goal directed activities.
Hallucinations - When you think that you perceive something, that does not exist in reality.
Delusions - A belief that is clearly false.
Co-morbidity - Two mental disorders at the same time.
Symptom overlap - When symptoms can be classified into different disorders.
Positive symptoms - Adding to people’s lives.
Negative symptoms - Taking away from people’s lives.
General Facts about Sz
The onset is typically in late adolescence and early adulthood. Men - 18-25 years Women - 15-35 years
1% chance of developing Sz.
The incidence of sz is 4 in 1000 people at some point in their life - Saha et al (2005)
Men are more likely to suffer than females.
The fully developed adult brain is 25!!!
Risk factors: Low socio-economic status, minority ethnicity, urban residence.
How Sz begins:
Chronic onset - Negative symptoms
A subtle change in a normal young person, who gradually loses drive and motivation. They start to drift away from friends. After months/years of this deterioration, more obvious signs of disturbance arrive eg. delusions or hallucinations.
Acute onset - Positive symptoms
Obvious signs such as hallucinations can appear quite suddenly, usually after a stressful event. The individual usually shows very disturbed behaviour within a few days.
Schizophrenia symptoms: Positive
Type 1: Positive symptoms - Two or more need to be present for a significant portion of time during a 1 month period.
Passivity experiences and thought disturbances -
Thought insertion - The belief that thoughts are being inserted into the mind from the outside, under the control of external forces eg. Government.
Thought withdrawal - The belief that thoughts are being removed from the mind under the control of external forces eg. Martians.
Primary delusions - Believing something that isn’t true.
Delusions of grandeur - The belief that you are/were important or powerful eg. Jesus Christ.
Delusions of persecutions - The belief that one is being plotted or conspired against, or being interfered with by certain organised groups.
Delusions of reference - The belief that inanimate objects, events (typically negative) have personal significance eg. the chair is talking to them.
Hallucinations - When you think that you perceive something, that doesn’t exist in reality.
Auditory - Hearing voices coming from outside the individuals head. They offer a running commentary on behaviour in the third person eg. “He is washing his hands”. Can be insulting or commanding, but may also be amusing or reassuring.
Somatosensory hallucinations - Involves weird sensations and changes in how the body feels eg. “burning” or “numb”.
Disorganised behaviour -
Disorganised speech - Frequent derailment/incoherence, which are called “word salads”, which are jumbled words said together. Ongoing disjointed or rambling monologues. The person could be talking to themselves or imagined people/voices.
Grossly disorganised/catatonic behaviour - An abnormal condition characterised by inactivity/mania and either extreme rigidity/flexibility of the limbs. Involves repetitive behaviour eg. “twirling hair”.
Schizophrenia symptoms: Negative
Alogia - Speech poverty - Disturbed speech in which the person says very little, or poverty of content in which the person talks to a normal extent, but conveys very little information, often using repetitive and vague phrases.
Echolalia - Pathological repetition of the words of others.
Anhedonia - The inability to experience pleasure; a lack of interest in pleasant experiences eg. sex.
Flat affect - The lack of emotional responses to all stimuli. Toneless speech and vacant/lifeless facial expressions.
Avolition - A lack of energy, a loss of interest and ability to carry out normal routines. Finding it difficult to begin or keep up with goal directed activities eg. lack of persistence in education.
DSM - 5 (Diagnostic statistical manual) 2013 - Diagnosis of Sz
Developed by the APA (American Psychological)
Criterion A)
Two or more of the following symptoms-
a) delusions
b) hallucinations
c) disorganised speech
d) grossly disorganised or catatonic behaviour
e) negative symptoms
ONLY ONE criterion A symptom is required if delusions are bizarre or hallucinations consist of a voice keeping up a running commentary on the person’s behaviour or thoughts. Additionally, if two or more voices are conversing with each other. Link to GAF score (global assessment of functioning).
Criterion B: Social/Occupational Dysfunction)
One or more major areas of functioning eg. work, interpersonal relations or self scare are marked below the level achieved prior to onset, for a significant portion of time.
Criterion C: Duration
Continuous signs of disturbance persist for at least 6 months. This 6 month period must include at least 1 month of symptoms that meet CA.
During non active periods, disturbance may be limited to negative symptoms or two or more symptoms in CA in attenuated form (reduced in force) eg. odd beliefs.
ICD - 10 (International classification system)
Developed in Europe by WHO
Two or more negative symptoms and positive symptoms present.
Key Words: Diagnosis of Schizophrenia
Reliability - Is it consistent eg. doctor’s diagnosis.
Validity - Is it measuring what it intends to measure eg. the symptoms.
Culture - Black males are more likely to be diagnosed.
Gender bias - Men are more likely to be diagnosed.
Symptom Overlap - When one symptom can be diagnosed as two different disorders eg. have they got dis associative identity or schizophrenia?
Comorbidity - Having two disorders together.
Being Sane in Insane places 1973 - Rosenhan’s study
Aims:
To illustrate the problems involved in determining the classification of normality and abnormality.
To illustrate the poor reliability of the diagnostic classification system.
To illustrate the negative consequences of being diagnosed as abnormal and the effects of institutionalisation.
Procedure:
- He carried out two studies in US psychiatric hospitals, to find out whether or not the medical staff could judge between mental normality and abnormality.
- 8 sane people (pseudo patients - pretending to be ill) using fake names sought admission to 12 hospitals.
- Voices were unclear, unfamiliar and of the same sex. They said single words like “empty”, “hollow” and “thud”.
- On admission to hospital, every pseudo patient stopped simulating any symptoms, said that they were fine and were experiencing no more symptoms.
- Their task was to: Seek release by convincing staff that they were sane and to observe and record their experience of being in the institution.
Results:
- Pseudo patients were admitted to hospital IN ALL CASES except ONE,with a diagnosis of sz.
- Their sanity WAS NEVER detected by staff - only by other patients.
- Length of stay ranged from 7-25 days. They were released with a diagnosis of “SZ IN REMISSION.”
Follow up study:
- To check the poor reliability of diagnosis, a later study was conducted, where a hospital had been informed to EXPECT PSEUDO PATIENTS over a 3 month period.
- During that time, 193 patients were admitted. 41 were suspected of being fakes, no pseudo patients who were actually medically mentally ill were sent, 35 patients tried to tell the doctors that they were fakes.
Being Sane in Insane places 1973 - Rosenhan’s study - A03 evaluation
Strengths:
- A valid field experiment, whilst still managing to control many variables eg. pseudo patients’ behaviour.
- Used a range of hospitals in DIFFERENT states. Allows the results to be generalised and has high ecological validity.
- RWA: Conducted over 30 years ago. Since then, manuals have IMPROVED and diagnostic practice is VERY DIFFERENT. For example, categories + definitions are OPERATIONALISED and MORE DETAILED. Psychiatrists now use standardised interview schedules when assessing patients.
Weakness:
- Lack of control groups, as there was only an experimental condition conducted.
- Ethical problems: Study involved DECEPTION, Contrast point : however it is clear that the studies ends outweighed its SLIGHTLY UNETHICAL means and data was kept CONFIDENTIALLY.
- Rosenhan potentially was being TOO HARD on psychiatric hospitals, as there is always AN OUTCRY when a patient is LET OUT OF CARE and gets into TROUBLE.
If the DSM and ICD were reliable:
Benefits of classification:
- Helps with a diagnosis for doctors to understand.
- Helps with the prescription of drugs, more clarity in treatment.
Disadvantages of classification:
- Cultural bias - Not used by everyone the same.
- Labelling people is unethical, might turn into self-fulfilling prophecy, which affects future prospects.
Reliability:
The extent to which psychiatrists can agree on the SAME DIAGNOSIS when INDEPENDENTLY assessing patients. For different diagnosticians using the same system, they should arrive at the same diagnosis.
Problem: KEY TERMS were not clearly defined. Clinicians used different techniques when interviewing and assessing patients, leading to different conclusions.
Issue 1: Inter Rater Reliability
Inter-rater reliability: A positive correlation of 0.8 is needed between two doctors.
Early versions of the DSM were not very reliable.
The key terms and categories were not clearly defined, so there was not good agreement between psychiatrists.
Use of different classification systems:
They both focus on different symptoms and duration eg. DSM = 6 months and more focus on social aspects, whereas ICD puts more focus on positive symptoms.
Subjectivity:
Diagnosis is heavily reliant on subjective judgements based on personal, cultural and social norms and the account given by the patient. The definitions in DSM/ICD are open to interpretation eg. What is a “bizarre” or “non-bizarre” delusion?
Issue 1: A03 - Evaluation
Weakness of RM-
P) Weakness of the diagnosis of sz is that it can lack inter-rater reliability, as both classification systems differ.
E) Beck (1962) –> Experienced clinicians who each relied on DSM only agreed on 54% of their diagnoses out of 153 PATIENTS. This was due to the vague criteria for diagnosis and inconsistencies in techniques to gather data.
E) Additionally –> Cheniaux et al (2009) had two psychiatrists independently diagnose 100 patients using both ICD and DSM criteria. It was found that inter-rater reliability was poor, as one psychiatrist diagnosed 26 with DSM and 44 with ICD criteria and the other one diagnosed 13 according to DSM and 24 to ICD.
L) This suggests that inter-rater reliability is low, as it relies heavily on subjective judgements and DIFFERENT classification systems, which lead to different diagnoses.
Issue 1: A03 - Evaluation
Support for the weakness -
Carney (2013) reports that inter-rater reliability for sz using DSM-V to diagnose is 0.46.
Despite the claims for increased reliability in DSM-III (and later revisions) over 30 years later, there is still little evidence that DSM is routinely used with high reliability by clinicians.
Whaley (2001) - found inter-rater reliability correlations in the diagnosis of sz as low as 0.11!
Issue 2: Test - Retest Reliability
Test Retest is when a test is performed twice on one person at two different times.
If they do the test again with the same person, they have to achieve the SAME DIAGNOSIS.
Lee et al (2011) - two tests examined –> measured switched and sustained attention –> results indicated STRONG reliability and were STABLE measures.
Issue 2: A03 - Evaluation
P) Strength of the DSM classification system is that an updated version has been created.
E) 1980 - DSM II - Designed to provide a more reliable system for classification. Additionally, the most recent version named the DSM V was released in 2013. It includes more detailed and operationalised categories and definitions for diagnosing Sz.
E) Furthermore, psychiatrists now use standardised interview schedules when assessing patients, which increases the consistency when diagnosing.
L) This increases the reliability of the classification system when diagnosing schizophrenia.
Issue 3: Cultural differences in diagnosis
The reliability of diagnosing Sz is challenged by the finding that there is massive variation between countries.
If we want to give reliable diagnoses, we need to find a CONSISTENT WORLDWIDE MEASURE to classify and diagnose sz.
Fernando (1981) found that Afro Carribbeans are more likely to be diagnosed with Sz compared to their white counterparts.
Barnes (2004) - Established cultural and racial differences in the diagnosis of Sz. CP: However, the prognosis for members of ethnic minority groups may 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) - Evidence to support this hypothesis. A study of 18 individuals with Sz. The sample was drawn from TWO non white minority groups (African-Americans and Latinos) and ONE majority group (white Americans).
Findings:
- White Americans were more symptomatic than members of the other 2 groups. Supports the ethnic culture hypothesis.
Issue 3: A03 - Evaluation
P) Weakness of diagnosis of sz - there are cultural differences evident, which reduces the reliability of diagnosis worldwide.
E) Copeland (1971) - challenges the reliability of the diagnosis of sz patients, as he gave 134 US and 194 British psychiatrists a description of a patient and found worrying results. Findings: 69% of the US psychiatrists diagnosed them, ONLY 2% of Brits did. Suggests that there appears to be a WORLDWIDE PROBLEM in reliability when diagnosing schizophrenia.
E) Additionally, Escobar (2012) found that white doctors tend to OVER-INTERPRET symptoms and DISTRUST black people’s honesty during diagnosis. L) SHOWS CLEAR CULTURAL BIAS, LOWERS THE RELIABILITY.
Issue 4: Stigmas + A03 - Evaluation
P) A weakness of the diagnosis of sz is that it lacks accuracy, as many cases go UNDIAGNOSED, due to SOCIAL STIGMAS AND REPERCUSSIONS. This leads to clinicians being reluctant to diagnose people.
E) Example - In Japan, schizophrenia literally translates to “disease of the disorganised mind”.
Kim and Berrios (2001) researched this and found that a “disorganised mind” is so STIGMATISED in Japan, that psychiatrists are RELUCTANT to tell patients of their conditions.
E) Therefore, only 20% of those with sz are ACTUALLY AWARE of it, while the other 80% are LEFT UNDIAGNOSED, which can lead to further problems.
L) Thus, it is evident that sz diagnosis is impacted by cultural differences.
Validity: Predictive Validity
Predictive validity - the extent to which the diagnosis can accurately predict the development and prognosis of sz.
High predictive validity - Desirable, would be clear how the disorder would develop.
In the same way, that people diagnosed as sz RARELY SHARE THE SAME SYMPTOMS or the SAME OUTCOMES.
Low predictive validity - A03 - Evaluation
Low predictive validity - Bleuer (1978) - 2000 schizophrenic patients in the study.
Found that 20% would have a full recovery, 40% would recover from positive symptoms and 40% would continue to have psychotic episodes.
Proves that how sz develops cannot really be predicted, as figures are not that accurate. It becomes more like a lottery, which is difficult to predict. If each person has such different outcomes after treatment, how can we be sure sz is ACTUALLY what they have.
Issue 1: Validity - Gender bias
The effect of gender can impact diagnosis.
The reasons for this can be gender-biased diagnostic criteria or clinicians basing their judgements on stereotypes held about gender.
Longenecker et al (2010) - Reviewed studies of the prevalence of schizophrenia. They found that since the 1980’s, men have been diagnosed with sz MORE OFTEN THAN WOMEN. Before this, there was no difference. It could be that men are more genetically vulnerable to developing it than women. Another explanation for this gender bias could be that female patients TYPICALLY FUNCTION BETTER than men and WILL BE MORE LIKELY TO WORK and HAVE GOOD FAMILY RELATIONSHIPS (Cotton et al 2009) which protects them.
Additionally, it is more acceptable for females to talk about their feelings and share their emotions.
Issue 1: Validity - Gender bias - A03 - Evaluation
P) Weakness - Validity of schizophrenia is that the effect of gender can impact diagnosis.
E) Loring + Powell (1998) selected 290 male and female psychiatrists and gave them case studies of schizophrenics and asked to judge the individuals using a diagnostic criteria.
Findings - When given the gender as male then 56% gave a diagnosis of sz. When described as female only 20% were diagnosed as schizophrenic. This difference was only seen when the psychiatrist was MALE.
C) Counter criticism - Collectivist cultures - equal rates in men and women with schizophrenia.
C) Clear gender bias when diagnosing patients.
