Biological Explanation S

• Genetic Explanation


  Genes code for biological processes, including variation in neural structure and biochemistry; collection of gene locations associated with higher risk of schizophrenia, making it polygenic
• Concordance Rates


  Higher in families than general population, with the closer related family members being higher risk, argued due to genetic similarity
• Neural Correlates


  Variations in neural structure and biochemistry that are correlated with increased risk
• Dopamine Hypothesis


  Symptoms are due to an imbalance of dopamine across the brain

  • Hyperdopaminergia - high levels in Brocas area linking to auditory hallucinations
  • Hypodopaminergia - low levels in frontal cortex linked to avolition or speech poverty
• Glutamate


  Excitory neurotransmitter involved in learning, attention and memory found in low quantities in people with schizophrenia
• Enlarged Ventricles


  Filled with cerebrospinal fluids, also correlated with schizophrenia
• (+/-) A03: Gottesman (1991)


  Found concordance rates for schizophrenia of:

  • 48% for MZ twins
  • 17% for DZ twins

  Suggests genetic factors, but not 100% so must be environmental role
• (+/-) A03: Tienari (2004)


  Studied biological children of schizophrenic mothers who had been adopted

  • 5.8% of children adopted into healthy families developed
  • 36.8% of children raised by dysfunctional families developed

  Supports genetic idea of Schizophrenia, but suggests a trigger factor
• (+) A03: Leucht (2013)


  Meta-analysis of 212 studies, found drug therapy for normalising dopamine levels were more effective than placebo, supporting idea of dopamine influencing schizophrenia
• (-) A03: Biological Determinism

  Determining schizophrenia is due to genetics and neurochemistry disempowers individuals when diagnosed and passively reliant on drugs, economic implications
• (-) A03: Diathesis-Stress Model


  More likely to be valid that biological alone due to the concordance rates presented, environmental trigger occurs to upbring the root of schizophrenia, being genetic