Schizophrenia

• Schizophrenia


  A mental disorder characterized by positive symptoms (pathological excesses - additional experiences like hallucinations & delusions) and negative symptoms (pathological deficits - loss of abilities like alogia & avolition)
• Positive symptoms


  • Hallucinations
  • Delusions
• Negative symptoms


  • Alogia (speech poverty)
  • Avolition (lack of motivation)
  • Social withdrawal
• Symptoms


  • Delusions - false beliefs
  • Hallucinations - disruption of perception
  • Disorganised speech - illogical speech that is hard to follow, jumping topics without coherence
  • Grossly disorganized or catatonic behaviour - unpredictable behaviour
  • Negative symptoms - avolition, social withdrawal, alogia
• Types of reliability


  • Inter-rater reliability - 2 clinicians
  • Test-retest validity - over time
• Validity


  Accuracy of diagnosis
• Types of validity


  • Criterion validity - use of two manuals could produce different results
• Rosenhan study


  • 8 mentally healthy individuals were diagnosed with schizophrenia after hearing voices saying "empty", "hollow", and "thud". They were admitted to 11 out of 12 hospitals, with a stay ranging from 7 to 52 days, with an average of 19 days.
• Rosenhan study showed low validity of schizophrenia diagnosis
• Cheniaux study


  • 100 participants, psychiatrist 1 diagnosed 44 ICD & 26 DSM, psychiatrist 2 diagnosed 24 ICD & 13 DSM
• Cheniaux study also showed low validity of schizophrenia diagnosis
• Comorbidity - with schizophrenia

  • Depression 50%
  • OCD 23%
• Gender Bias:

  Males are diagnosed with schizophrenia 1.4 times more than females
• Culture Bias:

  Afro-Caribbean men in Britain are 7 times more likely to be diagnosed with schizophrenia
• Symptom Overlap:

  It is hard to distinguish schizophrenia from bipolar disorder due to symptom overlap (delusions)
• Genetic explanation


  The higher the percentage of DNA shared with someone with schizophrenia, the higher the chance of developing schizophrenia
• Tienari adoption study


  • 6.7% of adoptees whose biological mothers had schizophrenia also had it, compared to 2% who were born to non-schizophrenic mothers
• Not 100% concordance rates, so genetics is not the only factor
• Tienari adoption study


  • Schizophrenia was more likely to develop in adoptive families rated as 'severely disturbed' compared to 'healthy' or 'mildly disturbed'
• Diathesis-stress model


  Vulnerability (diathesis) + trigger (stress) can lead to schizophrenia
• Neural explanation


  Schizophrenia is due to an overactivity in dopamine neurons, leading to increased neural activity
• Excessive dopamine activity contributes to positive symptoms of schizophrenia
• Drugs like clozapine have an instant effect on dopamine, suggesting dopamine may not be the sole cause of schizophrenia
• Postmortem studies have found excessive dopamine in the limbic system of schizophrenia sufferers, but it is difficult to establish cause and effect
• Cognitive explanations


  Schizophrenia is caused by dysfunctional thought processes
• Frith's theories


  • Dysfunctional meta-representation - can't recognise own thoughts = hallucinations
  • Central control dysfunction - cannot suppress automatic thoughts = speech poverty
• Cognitive explanations are descriptive, not explanatory, and it is difficult to establish cause and effect
• Cognitive Behavioural Therapy for Psychosis (CBTp) is a useful application that targets specific cognitive dysfunctions
• Concordance rates


  • MZ 48%
  • DZ 17%
  • Siblings 9%
• Schizophrenogenic mothers- Family dysfunction


  Psychodynamic, cold, rejecting and controlling (refrigerator mother). Leads to delusions.
• Bateson - Double bind theory

  Conflicting family communication, when 'wrong' love is withdrawn. Leads to disorganised thinking.
• Expressed emotion


  Level of expressed emotion. Negative EE - Criticism & hostility.
• High expressed emotion families show negative communication patterns, and patients with high EE are 4 times more likely to relapse than those with low EE families
• It is difficult to establish cause and effect with family dysfunction theories
• Typical antipsychotics


  Dopamine antagonists - block dopamine D2 receptors in the mesolimbic pathway, decreasing its activity, reduces positive symptoms
• Atypical antipsychotics


  Temporarily block D2 receptors, also have a strong affinity for serotonin receptors reducing its activity, reduces positive and negative symptoms as well as cognitive impairment
• Benefits of drug therapies

  • Widely accessible
  • Work quickly
  • Require little patient effort
• Drawbacks of drug therapies

  • Side effects - tardive dyskinesia, weight gain
  • Does not offer a cure
  • Can lead to relapse if not taken
• Cognitive Behavioural Therapy for Psychosis (CBTp)


  Helps to identify irrational thoughts and change them, focuses on hallucinations and delusions
• Family therapy


  Reduces expressed emotions (anger, guilt), family becomes a therapeutic alliance to improve beliefs of schizophrenia and manage balance of support and living own life