Biological explanations for schizophrenia

• What was the risk of developing schizophrenia for monozygotic twins according to Gottesman (1991)?


  48% risk of both developing schizophrenia.
• What do family studies suggest about the genetic influence on schizophrenia?

  They suggest a strong familial pattern indicating a genetic influence.
• What was the risk of developing schizophrenia for dizygotic twins according to Gottesman (1991)?

  17% risk of developing schizophrenia.
• What was the risk of developing schizophrenia for siblings according to Gottesman (1991)?

  9% risk of developing schizophrenia.
• What does polygenetic mean in the context of schizophrenia?

  It means schizophrenia arises from multiple genes, each contributing a small risk.
• What does aetiological heterogeneity refer to in schizophrenia?

  It refers to different combinations of genetic variations leading to schizophrenia in different individuals.
• How many genetic variations associated with schizophrenia did Ripke et al. (2014) identify?

  108 genetic variations.
• What is the dopamine hypothesis in relation to schizophrenia?

  It suggests that schizophrenia is related to abnormal dopamine functioning in the brain.
• What is hyperdopaminergia and its link to schizophrenia?

  It refers to high dopamine activity linked to positive symptoms like hallucinations and delusions.
• Which brain region is associated with high dopamine activity and positive symptoms of schizophrenia?

  The mesolimbic pathway.
• How does Broca's area relate to schizophrenia?

  It has an excess of dopamine receptors contributing to speech disorganization.
• What is hypodopaminergia in the context of schizophrenia?

  It refers to low dopamine activity in the prefrontal cortex.
• What cognitive functions are affected by reduced dopamine in the prefrontal cortex?

  Thinking, decision-making, and planning.
• What symptoms are associated with reduced dopamine in the prefrontal cortex?

  Cognitive and negative symptoms like avolition and impaired executive function.
• What brain region is associated with avolition in schizophrenia?

  The ventral striatum.
• What did Juckel et al. (2006) find regarding ventral striatum activity?

  They found a negative correlation between ventral striatum activity and overall negative symptoms of schizophrenia.
• What are auditory hallucinations linked to in the brain?

  Reduced activity in the superior temporal gyrus.
• Who found that patients experiencing auditory hallucinations showed lower activation in the superior temporal gyrus?

  Allen et al. (2007).
• What does reduced activation in the superior temporal gyrus provide evidence for?

  A neural basis for auditory hallucinations in schizophrenia.