Schizophrenia- Classification Flashcards
What is a positive symptom of SZ?
Symptoms that are not usually present in a normal person; an excess or distortion of normal functioning
Examples of positive symptoms
1) Delusions= cognitive experience, irrational beliefs
2) Hallucinations= unusual sensory experiences, auditory or visual
What is a negative symptom of SZ?
Symptoms which cause a decline in functioning; a loss of normal function
Examples of negative symptoms
1) Avolition= loosing interest or motivation
2) Alogia/ Speech Poverty= less likely to initiate conversation
2 ways of diagnosing SZ
1) DSM-V
2) ICD-11
What is the DSM-V?
Used in primarily the US
Patients must experience at least 2 of following symptoms:
- delusions - hallucinations - disorganised speech
- catatonic behaviour - negative symptoms
Continuous signs must be persistent for at least 6 months
What is the ICD-11?
Used worldwide- including the UK
Symptoms must be present most of the time lasting for at least one month; one of the following symptoms:
- thought insertion or withdrawal - delusions of control
- hallucinatory voices
Rosenhan: On Being Sane In Insane Places
12 hospitals, 5 states and 8 pseudopatients- once admitted to the hospital acted normally
11 were diagnosed with SZ, the mean hospital stay was 19 days and 7 were discharged with a diagnosis of SZ in remission
Rosenhan: Follow-up study
Pseudo patients would be seeking admission over the next 3 months; staff rate each new patient on confidence that the patient was really ill or a pseudo patient
No. of patients judged= 193
No. of patients confidently judged as pseudo patients by at least one member of staff= 41
No. of patients suspected by one psychiatrist= 23
No. of patients suspected by one psychiatrist AND one other staff member= 19
No. of patients actually sent to the hospital= 0
Rosenhan conclusion
He said his study demonstrated that psychiatrists cannot reliably tell the difference between someone with real or fake symptoms
1st study= Failure to detect sanity
2nd study= Failure to detect insanity
Reliability and Validity study
Cheniaux et al (2009)
Had 2 psychiatrists independently diagnose 100 patients using both DSM and ICD criteria
Psychiatrist 1: DSM= 26 ICD= 44
Psychiatrist 2: DSM= 13 ICD= 24
Suggested the ICD diagnoses more people and psychiatrist one also diagnoses more people
Therefore, suggests it has poor reliability as they do not agree= can’t consistently diagnose SZ
Reliability and Validity study
Osorio et al (2019)
Reported excellent reliability for diagnosis in 180 patients with SZ, using the DSM-V
Inter-rater reliability was +0.97
Test-retest reliability was +0.92
These findings suggest because we know more about schizophrenia nowadays we are able to diagnose it more consistently
Reasons reliability and validity of diagnoses may be limited
1) Symptom overlap
2) Co-morbitity
3) Cultural bias
4) Gender bias
What is symptom overlap?
The symptoms of schizophrenia also are consistently present in other mental disorders
How symptom overlap questions validity of the classification
It can cause misdiagnosis, if symptoms are present in other illnesses it makes it more difficult to diagnose patients
Implications of symptom overlap
Ketter (2005): points out that misdiagnosis due to symptom overlap can lead to years of delay in receiving relevant treatment; leads to longer suffering and further degeneration can occur, as well as high levels of suicide
Focusing on symptom overlap could save money and lives
What is co-morbitity?
Describes a person who suffers from two or more mental disorders at the same time
How co-morbitiy questions validity of the classification
It suggests the illneses are both individual and can ne treated as a joint condition
Evidence of co-morbitiy
Buckley et al: concluded that 50% of patients with SZ have:
- 50% had depression
- 47% had substance abuse
- 29% had post-traumatic stress disorder (PTSD)
- 23% had OCD
Shows SZ occurs alongside other illnesses; means treatment may be incorrect or less effective due to its co-existence with another condition
What is cultural bias?
Concerns the tendency to over/under diagnose members of other cultures as suffering from schizphorenia
Prevalance rate in the West Indies and UK is at around 1%
Evidence of cultural bias
Pinto and Jones (2008): Although there is a 1% prevalence rate in the uk, people of African-Caribbean origin are up to 9 times more liekly to be diagnosed with SZ, compared to White British people; high levels are more not present in African-Caribbean countries
Suggests higher diagnosis rates are not due to genetic vulnerability but instead a cultural bias
Social class impacts of classification
Keith et al (1991): lower classes are more likely to live in poverty and suffer from marital separation, suffer discrimination
1.9% of lower class are diagnosed with SZ
0.9% of middle class are diagnosed with SZ
0.4% of upper class are diagnosed with SZ
What is gender bias?
Tendency for the diagnostic criteria to be applied differently to make males and females and for their differences in the classification of the disorder
Evidence of gender bias
Loring and Powell (1988): Randomly selected 290 male and female psychiatrists to read 2 case articles of patients behaviour and asked to judge them using standard diagnostic criteria
When patients described as ‘male’ or had no info on gender, 56% received a SZ diagnosis
When patients were descried as ‘female’, only 20% received a SZ diagnosis- the gender bias did not appear evident amongst female psychiatrist
Conclusion= under-diagnosis is due to gender of patient and gender of the clinician
