Schizophrenia(biological explanations for schizophrenia)

Question 1

Genetic factors -

Answer 1

Inherited factors (hereditary) that make an individual more likely to develop a behaviour or mental disorder.

Question 2

Genetic factors - (family studies)

Answer 2

-Family studies have concluded that schizophrenia is more common along biological relatives of a person with schizophrenia.
-The closer the degree of genetic relatedness, the greater the risk.

Question 3

Family studies as a genetic explanation - (study)

Answer 3

Gottesman’s study, children with 2 schizophrenic parents had a concordance rate of 46%, children with one at 13% and siblings (with a brother or sister having schizophrenia) with a concordance rate of 9%.

The closer related you are to a family member with schizophrenia the more likely you are to have the genetic risk of being diagnosed with schizophrenia. Can be explored through Gottesmann’s large-scale family studies. Which explored % chance of schizophrenia from closely relatedness.
Auntie - 2%
Sibling - 9%
Identical twins - 48%
Family studies do share the same environments which may also explain % rates for example you may be much more likely to share the same environment with someone you live with compared with your Aunt who lives away from you. However, family studies do show the importance of genetic similarities in the development of schizophrenia.

Question 4

what does concordance rate mean?

Answer 4

The proportion of pairs of individuals that share a particular attribute, given that one of the individuals has that characteristic. (similarity)

Question 5

Twin studies as a genetic factor -

Answer 5

If monozygotic twins(genetically identical twins) are more concordant (similar) than dizygotic twins (who share 50% of genes) then this suggests they are more genetically similar.

Question 6

Twin studies as a genetic explanation(study) -

Answer 6

Joseph calculated that pooled data for all schizophrenias twin studies carried out to prior to 2001 which showed a concordance rate for MZ twins of 40.4% and 7.4% of DZ twins.

Question 7

Neural correlates -

Answer 7

Changes in neuronal events and mechanisms that result in the characteristic symptoms of a behaviour or mental disorder.

Question 8

The dopamine hypothesis -

Answer 8

-The hypothesis claims that an excess amount of dopamine in some regions in the brain is associated with positive symptoms of schizophrenia.
- Also believed to be high with D2 receptors (schizophrenics) on receiving neurons.
- This results in more dopamine firing and more being received.

Question 9

Drugs increasing dopaminergic activity -

Answer 9

• Amphetamine is a dopamine agonist (causes synapses to be flooded with the neurotransmitter)
• High amphetamines (dopamine releasing drug) in normal individuals can develop the characteristic symptoms of a schizophrenic episode.

Question 10

Drugs decreasing dopaminergic activity -

Answer 10

Although there are multiple antipsychotic drugs, they all block the activity of dopamine in the brain. This reduced neural pathway activity of dopamine in the brain. The drug reduces positive symptoms.

Question 11

The revised hypothesis was devised was by who?

Answer 11

Davis and Kahn

Question 12

The revised dopamine hypothesis

Answer 12

Proposed that the positive symptoms of schizophrenia are caused by an excess of dopamine in sub cortical areas of the brain (mesolimbic).
Negative and cognitive symptoms of schizophrenia are thought to arise from a deficit of dopamine in areas of the prefrontal cortex. (Mespcortical pathway)

Question 13

The prefrontal cortex as an area involved in schizophrenia -

Answer 13

• Main area in executive control (planning, reasoning and judgement)
• Shown to be impaired on schizophrenic patients
• Hyopthesised that the cognitive symptoms of schizophrenia results from defects within the PFC, and its connections with other areas of the brain (hippocampus).

Question 14

Research can support the ideas of family studies -