Diagnosis and classifications of schizophrenia

• Schizophrenia what is it?  

  A severe mental illness where contact with 

  reality and insight are impaired.

   It is a psychotic disorder. 

  It affects thought processes and one's 

  ability to determine reality

  Schizophrenia actually means split mind – which relates to split from reality rather than an actual split in the mind
• Schizophrenia

  The term schizophrenia was coined by Swiss psychiatrist Professor Bleuler on April 24th 1908 – he took the Greek word Schism which meant splitting and the Greek word Phren meaning soul, spirit or mind.  He saw schizophrenia as the splitting of psychic functioning.  

  ‘The splitting of the different psychic functions is one of the most important features.  In each case there is a more or less clear splitting of the psychological functions: as the disease becomes distinct, the personality loses its unity’
• Schizophrenia - Stats and prevalence

  • 1% suffer worldwide
  • Worldwide there are between 24-55 million sufferers – the vast difference in totals is due to the inadequately agreed diagnosis for the disorder
  • Britain spends approximately 2 billion a year on treatments and therapies for those suffering
  • It can present as one episode or as a lifelong condition
  • It is diagnosed more in men than women
• Positive symptoms focus on displaying of behaviours that show a concerning loss of touch with reality such as hallucinations and delusions. 

  These generally occur in acute, short episodes with more normal periods in between and sufferers generally respond well to medication.

  They ADD to the sufferers living experience
• Negative symptoms focus on displaying of behaviours that show a concerning disruption of normal emotions and actions. 

  These generally occur in longer-lasting episodes, and are resistant to medication.  They contribute most to sufferers not being able to function effectively in society, such as in relationships or at work.

  They SUBTRACT from the sufferers living experience!
• Diagnosis

  So, we have defined schizophrenia as a mental health condition (classification), but we haven’t explored issues of diagnosis – deciding who has schizophrenia. 

  There are two issues that we need to consider whilst diagnosing: 

  • Reliability of diagnosis (consistency) 
  • Validity of diagnosis (accuracy)
• Diagnosis

  Reliability – level of agreement on the diagnosis by different psychiatrists across time and cultures; stability of diagnosis over time given no change in symptoms. I.e. how far can the same diagnosis be repeated?

  Validity – the extent to which schizophrenia is a unique syndrome with characteristic, signs and symptoms
• Diagnosis

  There are two main diagnostic systems

  1. International Classification of Disease 11 (ICD 11)

  • Produced by the WHO - used in EU

  1. Diagnostic and Statistical Manual 5-TR (DSM 5-TR)

  • Produced by the APA  - used in USA
• Diagnostic manuals (in brief)

  For a schizophrenia diagnosis:

  DSM V-TR requires 

  One positive symptom – delusions, hallucinations or 

  speech disorganisation must be present for diagnosis

  ICD-10/11 requires

  Two or more negative symptoms present
• AO3 - Inter-rater reliability

  In the case of diagnosis, inter-rater reliability refers to the extent to which two or more mental health professionals arrive at the same diagnosis for the same person. 

  Cheniaux et al. (2009) had two psychiatrists independently diagnose 100 people using both DSM and ICD criteria. Their inter-rater reliability was very poor. One psychiatrist diagnosed 26 people with SZ according to the DSM and 44 according to the ICD, another only diagnosed 13 by DSM and 24 by ICD
• AO3 - Criterion validity

  A standard way to assess the validity of statistical manuals is to refer to their criterion validity. Criterion validity refers to whether different assessments will arrive at the same diagnosis for the same person. 

  Cheniaux et al. (2009) shows us that a person is much more likely to be diagnosed with SZ using the ICD compared to the DSM. Whether this is under or over diagnosis on either part we cannot be sure, but still the validity is low and ergo a weakness
• AO3 - Culture bias

  African americans and english people of Afro-Caribbean descent are several times more likely to be diagnosed with schizophrenia than white people BUT rates of schizophrenia are not significantly higher in Africa or the Caribbean 

  Why might this be happening then?
• One reason may be that positive symptoms such as hearing voices may be more acceptable in some African cultures therefore these individuals would never be diagnosed by their own communities. 

  However when these symptoms are reported to a medical practitioner from another culture, these symptoms are interpreted as bizarre and irrational 

  Further to this Escobar (2012) noted that most psychiatrists are white and therefore may over-interpret symptoms and distrust Afro-caribbeans during diagnosis