schizophrenia - topic 1 - clinical characteristics

Question 1

definition of schizophrenia

Answer 1

a long-term mental disorder of a type involving a breakdown in the relation between thought, emotion, and behaviour, leading to faulty perception, inappropriate actions and feelings, withdrawal from reality and personal relationships into fantasy and delusion, and a sense of mental fragmentation.

Question 2

main symptoms (according to DSM 5)

Answer 2

delusions 
hallucinations 
disorganised thinking (speech) 
grossly disorganised catatonic behaviour 
negative symptoms

Question 3

clinical characteristics

Answer 3

type 1: acute onset, symptoms appear quite suddenly, could be result of stress. within a few days individual may show quite distressed behaviour
type 2: takes place over time, more obvious symptoms, may be evident for months/years
positive symptoms
negative symptoms
-likely to develop in early adulthood late adolescence

Question 4

issues of classification: reliability

Answer 4

reliable classification system will make the same diagnosis time and time again

• predictive validity: if a diagnosis can predict the individuals behaviour
• cultural differences: presenting different symptoms in different cultures
• There is no universally agreed definition of schizophrenia. DSM IV is different from ICD-10. They are more similar than they were 40 years ago, however. Introduction of diagnosis systems has improved reliability.

Question 5

differences between dsm and icd

Answer 5

• dsm states symptoms must be evident for a period of 6 months, icd states only a month
• icd focuses on first rank symptoms but dsm focuses on the course of the disorder and functional impairment
• they classify different subtypes of schizophrenia

Question 6

validity study

Answer 6

ROSENHAN demonstrated lack of validity and reliability in the USA. Asked 8 individuals to act normally other than report hearing voices saying words like ‘thud’ ‘dull’. All 8 were diagnosed. 7 with schizophrenia and 1 with manic depression
This shows medical professionals couldnt tell the difference between genuinely ill people and people faking. Thus casting doubt on the reliability of schizophrenia as a diagnostic catagory.
Follow up: asked professionals to identify patients faking symptoms. 41 of 193 admissions were identified as fake when infact no fakes had been semt in.
BENTAL: it may be more effective if treatment was produced for each of the symptoms of schizophrenia and they were seen as a separate disorder.

Question 7

factors affecting reliability of diagnosis

Answer 7

• differences in procedures, clinicians using different systems.
• COOPER: american clinicians diagnosed schizophrenia twice as often as British clinicians who diagnosed manic depression twice as often
• CHENIAUX: ICD - 68/200 diagnosed with schizophrenia. DSM 39/200 diagnosed with schizophrenia
• subjective interpretation
• differences in patients

Question 8

reliability of diagnosis (consistency)

Answer 8

• reliability is necessary but not sufficient for validity of diagnosis as consistent diagnoses may still all be incorrect
• inter-rater reliability: clinicians all reaching the same diagnosis

Question 9

validity of diagnosis

Answer 9

• descriptive validity: are the symptoms right? defining medical illness through symptoms. patients with very different symptoms call all be diagnosed with schizophrenia
• aetiological validity: can mechanisms/causes be identified?
• predicitve validity: what is prognosis/reaction to treatment? How the illness has progressed over time and predict how they react to treatments