Diagnosis and Classification of Schizophrenia

• Schizophrenia definition


  • A type of psychosis marked by severe disruptions in psychological functioning
  • Ex. cognition, emotions and behaviours
  • And a loss of contact with external reality
• What classification system is used in the USA for schizophrenia?

  DSM V
• Who publishes the DSM V?

  American Psychiatric Association
• What classification system is used in Europe for schizophrenia?

  ICD-10
• How does the ICD-10 classify schizophrenia?

  Two or more negative symptoms are sufficient for diagnosis
• What are positive symptoms of schizophrenia?

  Behaviors that add to normal behavior, like delusions and hallucinations
• What is an example of a hallucination in schizophrenia?

  Hearing voices that others do not hear
• What are delusions in the context of schizophrenia?

  Beliefs that seem strange and can be easily proven wrong
• What do negative symptoms of schizophrenia reflect?

  A reduction or loss of normal functions
• What is speech poverty (alogia) in schizophrenia?

  A reduction in speech fluency and productivity
• What does avolition (apathy) refer to in schizophrenia?

  A reduction of interest and motivation
• What does diagnostic reliability mean in schizophrenia diagnosis?

  That a diagnosis must be repeatable
• What is inter-rater reliability?

  When different clinicians arrive at the same diagnosis for the same patients
• What statistic measures inter-rater reliability?

  Kappa score
• What kappa score indicates good inter-rater reliability?

  A score of 0.7 or above
• What was the kappa score for schizophrenia diagnosis in DSM-V trials according to Regier et al?

  0.46
• What does the subjective nature of diagnosis imply?

  That individual behavior is open to interpretation
• What did Cheniaux et al's study reveal about schizophrenia diagnosis?

  It suggested poor reliability in diagnosing schizophrenia
• What did Luhrman et al's research suggest about cultural influences on schizophrenia?

  That cultural environment affects experiences of hearing voices
• How many patients did Cheniaux et al diagnose using DSM and ICD criteria?

  100 patients
• How did participants from Ghana and India report their experiences with voices?

  They reported positive experiences with their voices
• How did US participants report their experiences with voices?

  They were more likely to report hateful and violent voices
• What does the ethnic culture hypothesis predict?

  That ethnic minority groups experience less distress from mental disorders
• What did Brekke and Barrio's study support?

  The ethnic culture hypothesis regarding schizophrenia
• What is validity in relation to diagnosis and classification?

  Whether the diagnosis accurately reflects the disorder
• What can gender bias in diagnosis lead to?

  Variations in diagnostic judgments based on gender
• What did Loring and Powell's study reveal about gender bias in schizophrenia diagnosis?

  Male patients were diagnosed more frequently than female patients
• What was the percentage of psychiatrists who diagnosed male patients with schizophrenia when gender was specified?

  56%
• What was the percentage of psychiatrists who diagnosed female patients with schizophrenia?

  20%
• What is symptom overlap in schizophrenia?

  Many symptoms of schizophrenia are found in other disorders
• What did Ellason and Ross find regarding dissociative identity disorder (DID)?

  People with DID have more schizophrenic symptoms than those diagnosed with schizophrenia
• What can misdiagnosis due to symptom overlap lead to?

  Years of delay in receiving relevant treatment
• What are the main components of the classification of schizophrenia?

  • DSM V: Used in the USA, focuses on positive symptoms
  • ICD-10: Used in Europe, requires two or more negative symptoms
  • Positive symptoms: Add-on behaviors like hallucinations and delusions
  • Negative symptoms: Reduction or loss of normal functions
• What are the strengths and weaknesses of inter-rater reliability in schizophrenia diagnosis?

  Strengths:

  • Ensures repeatability of diagnosis
  • Allows for consistency across clinicians

  
  

  Weaknesses:

  • Subjective interpretation of behavior
  • Low kappa scores indicate poor reliability
• How do cultural differences affect the diagnosis of schizophrenia?

  • Cultural influences can lead to variations in diagnosis
  • Experiences of symptoms like hearing voices differ across cultures
  • Ethnic culture hypothesis suggests minority groups may experience less distress
• What are the implications of gender bias in schizophrenia diagnosis?

  • Gender-based diagnostic criteria can affect accuracy
  • Male patients are diagnosed more frequently than female patients
  • Diagnosis influenced by the gender of both patient and clinician
• What is symptom overlap and its implications in schizophrenia diagnosis?

  • Symptoms of schizophrenia overlap with other disorders
  • Misdiagnosis can lead to delays in treatment
  • Important to differentiate between disorders for accurate diagnosis