Schizophrenia

• Schizophrenia

  A severe mental health disorder characterised by profound disruption of cognition and emotion, affecting language, thoughts, perception, emotions and their sense of self
• Schizophrenia

  • The schizophrenic believes things that can't be true (delusions) or hears voices and sees visions when there's no stimuli to create them (hallucinations)
  • 1% of the population are diagnosed between 15-35 yrs, with men and women affected equally
• Classification of schizophrenia


  Schizophrenia doesn't have a single defining characteristic but a collection of unrelated symptoms
• Major classification systems for mental disorders

  • International classification of disease (ICD-11)
  • Diagnostic and statistical manual (DSM 5 – USA)
• ICD-11 criteria for schizophrenia diagnosis


  Two or more symptoms including at least 1 positive symptom, with major systems present for a month or longer
• DSM 5 criteria for schizophrenia diagnosis

  Only 1 positive symptom lasting for at least a month
• Positive symptoms of schizophrenia

  • Delusions
  • Hallucinations
  • Catatonic behaviour
  • Disorganised speech
• Delusions

  Bizarre beliefs that seem real to someone with schizophrenia but aren't, including paranoid, grandiose, and referential delusions
• Hallucinations


  Bizarre, unrealistic perceptions of the environment, including auditory, visual, and tactile hallucinations
• Catatonic behaviour


  Characterised by a reduced reaction to the immediate environment, rigid postures, or aimless motor activities
• Disorganised speech


  Result of abnormal thought processes where the person has problems organising their own thoughts, leading to jumping from one topic to another mid-sentence or incoherent speech
• Negative symptoms of schizophrenia

  • Speech poverty (alogia)
  • Avolition
  • Affective flattening
  • Anhedonia
• Speech poverty (alogia)


  Reduction in the amount and quality of speech accompanied by a delay in the sufferer's response in conversations
• Avolition

  Severe loss of motivation to carry out everyday tasks and difficulty in beginning or keeping up with goal-directed activities
• Affective flattening


  Reduction in range of expressions, tone, eye contact and body language compared to those without this symptom
• Anhedonia


  Loss of interest in pleasure in almost all activities or lack of reactivity to pleasurable stimuli, including physical and social anhedonia
• Reliability

  Consistency in whether we can gain consistent results when classifying/diagnosing schizophrenia, measured by inter-rater reliability
• Inter-rater reliability

  The extent to which different health professionals would agree on the same diagnosis regardless of time or culture, measured by a Kappa score
• Regier et al found the DSM-5 trials in the diagnosis of schizophrenia have a Kappa score of 0.46, suggesting inconsistent diagnosis between health professionals
• Osorio et al found great agreement between clinicians provided they use the same diagnostic system, with excellent reliability of the DSM 5
• Validity

  The accuracy and extent to which the classification systems accurately outline the signs and symptoms of schizophrenia and health professionals accurately diagnose it
• Cheniaux (2009) found poor inter-rater reliability and validity in the classification of schizophrenia, as two psychiatrists diagnosed double the number of patients using the ICD compared to the DSM
• Factors affecting reliability and validity of schizophrenia diagnosis


  • Symptom overlap
  • Co-morbidity
  • Gender bias
  • Culture bias
• Symptom overlap, where two or more conditions share similar symptoms, can question the validity and reliability of schizophrenia diagnosis
• Co-morbidity, where two illnesses/conditions occur simultaneously, can also question the validity and reliability of schizophrenia diagnosis
• Gender bias, where psychological research/theories don't represent the experiences of both men and women, can affect the reliability and validity of schizophrenia diagnosis
• Culture bias, the tendency to interpret behaviour from the perspective of one's own culture, can affect the reliability and validity of schizophrenia diagnosis
• Biological explanations for schizophrenia

  • Genetic theory
  • Neural correlates
• Genetic theory


  Schizophrenia is hereditary and passed between generations through genes, so some are born with a predisposition to it
• Research supports the genetic theory, with higher concordance rates for schizophrenia in monozygotic twins compared to dizygotic twins and adopted children of schizophrenic mothers
• Neural correlates


  Abnormalities in specific brain areas, such as enlarged ventricles and imbalances in neurotransmitters like dopamine, are associated with the development of schizophrenia
• The dopamine hypothesis suggests that those with schizophrenia have too much dopamine activity in subcortical areas but too little in the prefrontal cortex, contributing to positive and negative symptoms respectively
• Strengths of the biological explanation

  • Practical applications in drug therapy
  • Practical applications in genetic counselling
• Antipsychotic drugs based on the biological explanation can reduce around 20% of schizophrenia symptoms, showing the explanation is too reductionist and doesn't consider other factors
• Genetic counselling based on the biological explanation only gives a crude estimate of the risk of an unborn child developing schizophrenia, without considering environmental factors
• The dopamine hypothesis is too simplistic, as evidence shows multiple neurotransmitters are involved in the development of schizophrenia
• Psychological explanations for schizophrenia

  • Family dysfunction
• Family dysfunction explanation

  The individual develops schizophrenia due to being raised in a dysfunctional family environment with high levels of interpersonal conflict and faulty communication patterns
• Schizophrenogenic mother

  A cold, controlling, rejecting, and emotionally unresponsive mother who builds a family climate characterised by tension and secrecy, leading to distrust and paranoid delusions in the child
• Double-bind communication


  Faulty communication patterns where the parent communicates a verbal message that is not matched by their non-verbal messages, leaving the child confused about how to respond correctly