Classification of Schizophrenia

• DSM-5


  Classification tool globalised for mental health, two of the following symptoms need to be present for at least a month, one being positive
• Positive Symptoms


  Experiences that are in addition to normal experiences

  • Hallucination - additional sensory experiences e.g. seeing distortions
  • Delusions - irrational beliefs about themselves or world e.g. persecution, grandeur
• Negative Symptoms


  Loss of normal experience and abilities

  • Avolition - lack of purpose, no energy, lack of hygeine
  • Speech Poverty - brief verbal communication, loss of quality and quantity of response; can be seen as positive if excessive disorganised speech e.g. wandering off topic
• Reliability in Diagnosis


  Inter-rater reliability measures if 2 observes agree e.g. if doctors gave the same diagnosis; Test-retest is if the doctor gave the same diagnosis over time with the same symptoms
• Validity in Diagnosis


  Validity questions if a person has the disorder when diagnosed, or if schizophrenia is a real disorder with clear and unique symptoms
• (-) A03: Beck (1963)


  Found 153 patients diagnosed by multiple doctors had only a 54% concordance rate between assessment; suggesting there is low inter-rater reliability in diagnosis, also suggesting there may be incorrect diagnosis
• Co-Morbidity


  Schizophrenia is often diagnosed with other disorders, this could lead to inaccurate diagnosis of schizophrenia when it could be severe depression
• Symptom Overlap


  Bipolar disorder also has hallucinations and delusions (positive symptoms), if 2 disorders are so similar they may not be distinct and should be redefined
• (+) A03: Buckley (2009)


  Found co-morbidity rates with schizophrenia, showing common overlap with diagnosis

  • 50% with depression
  • 47% with drug abuse
  • 29% with PTSD
  • 23% with OCD
• Gender Bias - Cotton


  Argues women's experience of schizophrenia is taken less serious and underdiagnosed compared to men due to womens better social coping strategies
• Culture Bias - Fernando

  People of Afro-Carribean heritage in the UK are up to 9x more likely to be diagnosed with schizophrenia; argued this is due to "category failure" when Western definitions of mental illness are applied to people from Non-Western cultures
• (+) A03: Loring + Powell (1988)


  290 Psychiatrists two identical case studies altering ethnicity and gender

  • Found overdiagnosis in black client, and underdiagnosis if client was female
  • Most accurate diagnosis was when individual was the same gender and race as the psychiatrist