Classification and symptoms Flashcards
What percentage of the world population has schizophrenia?
1%
Which gender is schizophrenia more common in?
Men
Which two systems for classification are used?
ICD-10
DSM-5
How is schizophrenia diagnosed by DSM?
One positive symptom, eg. delusions, hallucinations or speech disorganisations
How is schizophrenia diagnosed by ICD?
2 or more negative symptoms
What are characteristics of catatonic schizophrenia?
Disturbance of movement leaving the sufferer immobile or alternatively overactive
What is a positive symptom?
Symptoms additional to ordinary existence
What are some examples of positive symptoms?
Delusions
Hallucinations
What is a hallucination?
Unusual sensory experiences
Some related to events in the environment and others are not and are voices heard in the head, either talking or criticising
What is a delusion?
Irrational belief
Common involve believing they are Jesus or Napoleon
What is a negative symptom?
Loss of usual abilities
What are some examples of negative symptoms?
Avolution
Speech poverty
What is avolition?
Finding it difficult to begin or keep up with a goal directed activity
also known as apathy
What are the three identifying signs of avolution, as identified by Andreason (1982)?
Poor hygiene and grooming
Lack of interest in work and education
Lack of energy
What is speech poverty?
Changes in speech patterns
How does ICD describe speech poverty?
Negative symptom
Reduction in amount and quality of speech
How is speech poverty seen?
Speech disorganisation in which speech becomes incoherent or the speaker changes topic mid sentence
How does DSM describe speech poverty?
as a positive symptom
What did Ellie Cheniaux find (2009)?
She had 2 independent psychiatrists independently diagnose 100 patients using DSM and ICD.
Inter rater reliability was poor with one psychiatrist diagnosing 26 with Sz according to DSM and 44 according to ICD.
The other diagnosed 13 according to DSM and 24 according to ICD
What is reliability?
The extent of consistency
What is validity?
The extent to which we are measuring what we set out to measure
How is the validity of diagnosis a weakness?
Criterion validity is used to see if using separate systems to diagnose come to the same outcome.
Sz is more likely to be diagnosed using ICD
What is co-morbidity?
The phenomenon that 2 or more conditions occur together.
What is the issue with co-morbidity?
If conditions occur together a lot of the time, it calls into question the validity of their diagnosis and classification because they may be one condition