diagnosis and classification

• classification

  • by ICD-10 and DSM-5
• positive symptoms

  • additional experiences beyond ordinary living
  • hallucinations = unusual sensory experiences e.g voices criticising the individual
  • delusions = irrational beliefs e.g being an important historical figure such as jesus
• negative symptoms

  • avolition = finding it difficult to keep up with or begin a goal-directed activity e.g poor hygiene and grooming
  • speech poverty = reduction in amount and quality of speech sometimes even delays in verbal responses when having a conversation
• weakness

  • reliability
  • two psychiatrists independently diagnosed 100 people using ICD and DSM
  • diagnosed 26 using ICD and 44 using DSM
  • inter-rater reliability was low
• weakness

  • validity
  • more likely to be diagnosed with sz under ICD than DSM
  • suggests its ever under or over diagnosed
  • poor validity
• weakness

  • symptom overlap
  • sz and bipolar both involve positive symptoms e.g delusions and negative symptoms e.g avolition
  • questions validity of the diagnosis of both conditions
  • may be wrongly diagnosed