introduction to schizophrenia

• Schizophrenia is a serious mental disorder affecting 1% of population and it is more common in males, city dwellers and lower social economic groups
• diagnosis- identifly symptoms and we use classification system to identify the disorder

  classification- identify symptoms that go together
• the 2 classification systems are :

  • DSM-5- one postive symptom must be present
  • ICD-10- 2 or more negative symptoms are sufficient for diagnosis
• positive symptoms are additional experiences beyond those of ordinary experience
• the positive symptoms of schizophrenia are:

  • hallucinations- unusual sensory experiences that have no basis in reality or distorted perceptions of real things. For example, hearing voices or seeing people
  • delusions- beliefs that no basis in reality. For example, beliefs about being a very important person or the victim of a conspiracy
• negative symptoms of schizophrenia are loss of usual abilities and experiences
• the 2 negative symptoms of schizophrenia are:

  • speech poverty- a reduction in the amount and quality of speech. This may include a delay in verbal responses during conversation
  • avolition- severe loss of motivation to carry out everyday tasks like work or personal care. It results in lowered activity levels and unwillingness to carry out goal-directed behaviours
• One strength of diagnosis of schizophrenia is good reliability. A reliable diagnosis is consistent between clinicians and between occasions. Osorio et al. report excellent reliability for schizophrenia diagnosis as it has an inter-rater agreement of +.97 and test-retest reliability of +.92. This means that the diagnosis of schizophrenia is consistently applied
• One limitation of diagnosis of schizophrenia is low validity. Criterion validity involves seeing whether different procedures used to assess the same individuals arrive at the same diagnosis. Cheniaux et al. had 2 psychiatrists independently assess the same 100 clients. 68 were diagnosee with schizophrenia with ICD-10 and 39 with DSM-5. This means that schizophrenia is either over or under diagnosed, suggesting that criterion validity is low.
• One limitation of schizophrenia is co-morbidity with other conditions. If conditions often co-occur then they might be a single condition. Schizophrenia is commonly diagnosed with other conditions. For example, Buckley et al. concluded that schizophrenia is co-morbid with depression (50% of cases), substance abuse (47%) or OCD (23%). This suggests that schizophrenia may not exist as a distinct condition
• One limitation of schizophrenia is gender bias. Men are diagnosed with schizophrenia more often than women, in a ratio of 1:4. This could be because men are more genetically vulnerable, or women have better social support, masking symptoms. This means that some women with schizophrenia aren’t diagnosed so miss out on helpful treatment