Biological explanations for schizophrenia

Question 1

What does the genetic explanation for SZ suggest?

Answer 1

• Sz is inherited
• driven by biological process driven by the activity of certain genes like neurotransmitter levels and brain development

Question 2

how is SZ a polygenetic disorder?

Answer 2

• no one ‘ SZ gene’
• collection of gene locations associated with higher risk of developing SZ

Question 3

concordance rates of genetics on SZ?

Answer 3

• if SZ is genetic, the closer to people are to being related and one has SZ there is an increased likelihood of the other person having disorder

Question 4

concordance rates of genetics on SZ: Gottesman (1991) twin studies

Answer 4

• using twin studies
• monozygotic twins are genetically identical and almost always share environments
• case study:
• gottesman found a concordance rate of 48% for monozygotic twins and 17% for dizygotic twins
• compared to gen pop of 1%
• suggest genetic aspect of SZ

Question 5

concordance rates of genetic on SZ: Tienari adoption studies

Answer 5

• looked at biological children of SZ mothers
• 5.8% of children who were adopted into psychologically healthy families developed SZ
• compared to 36.8% of children in dysfunctional families

Question 6

what is a neural correlate?

Answer 6

• variation in neural structure and biological chemistry correlated with the increased risk of developing SZ

Question 7

what is the dopamine hypothesis?

Answer 7

• symptoms of SZ are associated with too much or an imbalance of dopamine neurotransmitter across the brain
• excessive dopamine in speech centers= auditory hallucinations
• lower dopamine levels in areas like frontal cortex= negative symptoms like avolition

Question 8

how did the dopamine hypothesis come about?

Answer 8

• observations of releasing dopamine drugs e.g. L-dopa can produce SZ like symptoms In healthy patients
• Anti- psychotic drugs= decrease symptoms of SZ and reduce dopamine levels

Question 9

other neurotransmitters implicated in SZ development

Answer 9

• Glutamate= excitatory neurotransmitter involved in learning, attention and memory is low in quantity in people with SZ

Question 10

evidence of anti psychotic drugs that influence the dopamine system: the dopamine hypothesis

Answer 10

• meta analysis of 212 studies
• assessed effectiveness of anti psychotic drug treatments on leveling out dopamine
• found drugs more effective than placebo
• effectiveness of these drugs on dopamine levels means there’s validity behind the biological theory of SZ

Question 11

Ventricles on people with SZ

Answer 11

• ppl with SZ have enlarged ventricles
  + research using CT scans found people with SZ have larger than average ventricles
• structural difference may be linked to the cause
• BUT correlational study so having SZ may cause large ventricles not the other way around
• could be a 3rd factor linked to both e.g. medication

Question 12

Evaluation biologically determinist: biological explanation assumes SZ is inevitable

Answer 12

• genetic basis assumes SZ is biologically determined
• some people may feel dis empowered when diagnosed
• other approaches like the cognitive has soft determinist perspective suggesting mental processes can be changed via free will

Question 13

Evaluation biologically reductionist: fails to consider psychological factors in developing SZ

Answer 13

• fails to consider a range of psychological aspects of SZ
• e.g. expressed emotion that seemed to have a large influence on the development and relapse of the disorder

Question 14

Evaluation holistic approach may be better: the diathesis- stress model

Answer 14

• a full holistic explanation of SZ would be the diathesis-stress model
• the root cause of the disorder is a biological/ genetic weakness
• an environmental stressor, like family stress triggers the disorder
• considers multiple aspects as causes