Schizophrenia Flashcards
1
Q
What is schizophrenia?
A
- This is a serious mental disorder which affects about 1% of the population.
- Symptoms of SZ can interfere severely with daily activities and sometimes results in sufferers being hospitalised or becoming homeless.
2
Q
How is schizophrenia classified and diagnosed?
A
- It is a cluster of symptoms which all appear unrelated.
- Two major systems for the classification of mental health disorders are ICD-10 and DSM-5.
- These both differ slightly in their classification of SZ.
3
Q
How does the ICD-10 classify SZ?
A
- Two or more negative symptoms being present are sufficient for the diagnosis of SZ using the ICD-10.
- Recognises subtypes of SZ: hebephrenic SZ, paranoid SZ and catatonic SZ.
4
Q
What is hebephrenic SZ?
A
- This primarily involves the negative symptoms of SZ.
- Behaviour is generally disorganised and not goal-directed.
- Symptoms include absence of expressed emotion, large mood swings and social withdrawal.
5
Q
What is paranoid SZ?
A
- This is where symptoms such as powerful delusions and hallucinations are present, however patient remains emotionally unresponsive.
- These patients are more alert than patients with other types of SZ.
6
Q
What is catatonic SZ?
A
- Characterised by disturbances of movement or severe motor disabilities.
- This could leave sufferer immobile (total immobility for hours with blank staring) or alternatively overactive.
- e.g. gesture repeatedly, using complex sequences of finger, hand and arm movements.
- Types include echolalia (repeat words) and echopraxia (repeat/imitate body movements).
7
Q
What are positive symptoms? Give some examples.
A
- Positive symptoms are additional experiences beyond those of ordinary existence.
- Such as hallucinations: unusual sensory experiences e.g. hearing voices, Can affect any sense.
- Delusions: irrational beliefs, such as delusions of grandeur (being important historical figure), delusions of persecution and delusions of the body (part of them being under external control).
8
Q
What are negative symptoms? Give some examples.
A
- Loss of usual abilities and experiences.
- Such as avolition (apathy), which is finding it difficult to keep up with goal-directed activities. Sufferers of SZ often have sharply reduced motivation to carry out a range of activities.
- Speech poverty, changes in patterns of speech.
9
Q
What are the differences in which ICD-10 and DSM-5 acknowledge speech poverty?
A
- ICD-10: Classified as a negative symptom, focuses on reduction in the amount and quality of speech.
- DSM-5: Classified as a positive symptom, places emphasis on speech disorganisation - speech becomes incoherent or speaker changes topic mid-sentence.
10
Q
Evaluate the validity and reliability of diagnosis and classification of SZ.
A
- Cheniaux et al. told two psychiatrists to independently diagnose 100 patients using both ICD-10 and DSM-5.
- One diagnosed 44 patients with SZ using ICD-10 and 26 using DSM-5. Other diagnosed 24 patients with ICD-10 and 13 with DSM-5.
Reliability: inter-rater reliability, whether two different assessors arrive at same diagnosis for same patient. Poor inter-rater reliability. - Validity, in particular criterion validity, is whether two different assessment systems arrive at same diagnosis for same patient. Poor validity, SZ more likely to be diagnosed with ICD than DSM. ICD may be over-diagnosing or DSM may be under-diagnosing.
11
Q
Why is co-morbidity an issue with the diagnosis and classification of SZ?
A
- This is where two or more conditions occur together which raises the question of whether they are actually one condition.
- E.g. nearly 50% of all patients diagnosed with SZ are also diagnosed with depression and 23% diagnosed with OCD.
- Problem with diagnosis as it may mean we are quite bad at distinguishing between the two conditions.
- Problem with classification as if severe depression looks a lot like SZ then it may be better to diagnose them as one.
12
Q
What are other issues with the diagnosis and classification of SZ?
A
- Cultural bias: AA’s and English people with Afro Carib descent more likely to be diagnosed with SZ than white counterparts.
- May be because hearing voices is acceptable in African cultures or Javier Escobar pointed out many white psychiatrists over-interpret symptoms or distrust honesty of black patients during diagnosis.
13
Q
Outline the aspect of heredity in the biological explanation of SZ.
A
- Inherited via genes
- Family studies done show SZ likely in individual who has biological relative suffering from SZ.
- Closer degree of genetic relatedness leads to higher risk e.g. MZ twins share 100% of genes compared with 50% in DZ twins, Gottesman et al. found concordance rate of 48% in MZ twins and 17% in DZ twins - shows genes play important role in SZ.
14
Q
Outline the aspect of candidate genes in the biological explanation of SZ.
A
- Appears SZ is associated with multiple genes - polygenic.
- Ripke combined all previous data from genome-wide studies and compared genetic makeup of 37,000 SZ patients with 113,000 controls.
- Found 108 separate genetic variations associated with increased risk of SZ.
- Genes associated with increased risk included those coding for functioning of a number of neurotransmitters including dopamine.
15
Q
Outline the dopamine hypothesis of SZ.
A
- Dopamine is a neurotransmitter involved in functioning of several systems of the brain.
- Hyperdopaminergia in subcortex: high levels of dopamine in subcortex (central areas) of brain. e.g. excess of dopamine in Broca’s area which is responsible for speech production associated with speech poverty and auditory hallucination.
- Hypodopaminergia in cortex: low levels of dopamine in pre frontal cortex (responsible for thinking and decision making) associated with the negative symptoms of SZ.
