biological explanation

Question 1

genetic factors

Answer 1

schiz tends to run in families who are genetically related

Question 2

genetic factors - family studies

Answer 2

• closer you are genetically related to a family member with schiz more likely you are to develop it
• children with 2 schizz parents have concordance rate of 46%
• one parent is 13%

Question 3

genetic factors - twin studies

Answer 3

• mz twins (genetically identical) have concordance rate of 40%
• dz twins have 7% concordance rate

Question 4

genetic factors - adoption studies

Answer 4

• Tienari compared 164 adoptees in Finland who had schiz biological mothers with 197 adoptees with non-schiz mothers
• first group - 11 schiz kids
• second group - 4 schiz kids

Question 5

dopamine hypothesis

Answer 5

excess of dopamine in certain region of brain is associated with positive symptom of schiz

Question 6

dopamine hypothesis - drugs INCREASING dopaminegic activity

Answer 6

• amphetamine activates dopamine receptors causing an excess in it
• normal people exposed to large doses of such drugs can develop symptoms of schiz

Question 7

dopamine hypothesis - drugs REDUCING dopaminergic activity

Answer 7

• anti-p drugs block activity of dopamine in brain
• such drugs eliminate symptoms like hallucinations & delusions proving it influences development of it

Question 8

dopamine hypothesis - revised dopamine hypothesis

Answer 8

• Davis & Kahn said positive symptoms caused by deficit of dopamine in prefrontal cortex

Question 9

neural correlates - specific brain areas

Answer 9

PREFRONTAL CORTEX - main area of brain involved with executive control (planning, reasoning, judgment) & is impaired in schiz
HIPPOCAMPUS - deficits in nerve connections between the hippocampus & PFC causes issues with working memory & cognitive impairment in schiz

Question 10

neural connections - grey & white matter

Answer 10

GREY MATTER - reduced grey matter in their brain
WHITE MATTER 0 nerve fibres covered in myelin & helps gain info quickly through the nervous system & have reduced myelination of white matter

Question 11

evaluation of genetic factors

Answer 11

MZ TWINS ENCOUNTER MORE SIMILAR ENVIRONMENT: by emphasising genetics twin studies assume that the environment are the same for MZ & DZ twins & in fact MZ rwins are treated more similarly
LIMITATION: higher concordance rate isn’t due to genetics but to similar environemt
ADOPTEES MAY BE SELECTIVELY PLACED: very unlikely that kids born to schiz women would be placed into same type of adoptive family as children with a normal biological background
LIMITATION: higher concordance rate may be due to type of adopted family

Question 12

evaluation of dopamine hypothesis

Answer 12

EVIDENCE FROM TREATMENT: drug treatments that attempt to change levels of dopamine in the brain are very successful. research proves that anti-p drugs are successful at treating positive & negative symptoms of schiz
STRENGTH: success of such drugs prove that dopamine influences development
CHALLENGES TO DH: Nall argues anti-p drugs don’t stop hallucinations & delusions in 1/3 of those with symptoms/ also claims some with normal levels still experience the symptoms
LIMITATION: dopamine may not be only cause on development of schiz

Question 13

evaluation of neural correlates

Answer 13

SUPPORT FOR INFLUENCE OF GREY MATTER DEFICITS: vita carried out meta analysis of 19 studies. schiz patients did show reduced grey matter in brain compared to healthy people
STRENGTH: clearly schizs do show patterns of dysfunctional brain activity
IMPLICATIONS FOR TREATMENT: with knowledge in neural correlates early intervention can prevent development of schiz. with better understanding of how it develops, researchers can detect loss of brain tissue early & treat at risk patients
STRENGTH: now clinicians can treat symptoms quick