schizophrenia

• What are the two major systems for the classification of mental disorder?

  • ICD-10
  • DSM-5
• How do the DSM-5 and the ICD-10 differ in terms of classifying schizophrenia?

  • for the DSM-5 one or more positive symptoms must be present
  • for the ICD-10 two or more negative symptoms are sufficient
• What are the positive symptoms of schizophrenia?

  • hallucinations - distorted perceptions of reality 
  • Delusions - beliefs that are not based in reality 
• What are the negative symptoms of schizophrenia?

  • speech poverty - a reduction in the quality and amount of speech 
  • Avolition - a lack of desire and motivation for anything 
  • negative symptoms involve the loss of usual abilities and experiences
• Schizophrenia is a form of psychosis
• What is psychosis?

  • when some people loose in touch with reality
  • they may hear or see things that aren't there (hallucinations)
  • they may believe things that aren't true (delusions)
• What is type 1 schizophrenia?

  • an acute type characterised by positive symptoms and better prospects of recovery
• What is type 2 schizophrenia?

  • A chronic type characterised by negative symptoms and poorer prospects of recovery
• Negative symptoms are defined as and include:

  • Type 2 schizophrenia
  • Occur in chronic, longer lasting episodes and resistant to medication 
  • Contribute to sufferers not being able to function effectively in society such as in relationships or work
• How can reliability of diagnosis be tested?

  • test-retest reliability: occurs when clinician makes the same diagnosis on separate occasions from the same information
  • inter-rater reliability: occurs when different clinicians make identical, independent diagnosis of the same patient
• Research that supports reliability of classification system over time

  • Beck et al 54 % concordance rate between experienced practitioners diagnosis when assessing patients
  • while Soderberg et al reported a concordance rate of 81 % using DSM-5
• Research evidence against the reliability of diagnosis of schizophrenia

  • Read et al reported test-retest reliability of schizophrenia to only have 37 % concordance rate
  • noted that in a study when British and US psychiatrists provided a diagnosis on the base of a description