Heston

Question 1

what is schizophrenia?

Answer 1

a serious mental disorder characterized by disordered thoughts, delusions, hallucinations and often bizarre behaviours

Question 2

positive symptoms of schizophrenia

Answer 2

• hallucinations
• delusions
• paranoid thoughts
• racing thoughts

Question 3

negative symptoms

Answer 3

• low motivation
• decreased speech
• loss of interest in life
• social withdrawal

Question 4

possible cause of SZ, nature debate

Answer 4

dopamine hypothesis of SZ suggests that its caused by too much dopamine or too many dopamine receptors,

Question 5

possible cause of SZ, nurture debate

Answer 5

social causation hypothesis suggests experiencing economic hardships increases the risk of SZ

Question 6

aim and background

Answer 6

prior 1960s, some evidence from twin studies which suggested SZ was partly due to genetics, no adoption studies were carried out
the aim was to see how many adopted children of biological mothers with SZ would go on to develop it themselves. if a significant number did so it would constitute evidence to the roles of genes in SZ

Question 7

sample

Answer 7

experimental subjects were born to SZ mothers confined to an oregon state psychiatric hospital and these children had to be adopted at birth because their mothers were suffering from SZ
- matched group of 50 adoptees whose mothers had no mental background
- 47 adults ppt in interviews

Question 8

procedure

Answer 8

47 subjects were contacted by letter and asked to participate in a personal interview.
the interview was standardised
adults were interviewed in order to see whether any of them had gone to develop SZ themselves

Question 9

what were the risks off developing SZ if one parent had it?

Answer 9

10%

Question 10

what was the rationale of the study

Answer 10

if there were no genetic influences on SZ, we would expect none or perhaps one of the people with a bio mother with SZ to develop it. If SZ were the result of genetic factors, we would expect about 10% of the children with bio mother with SZ to develop it. a control group was needed to eliminate the possibility the adoption was responsible for SZ

Question 11

results

Answer 11

out of 47 adults interviewed whose mothers had SZ, 5 were hospitalised with it. means 10% of the adopted children with SZ mothers developed SZ - exactly the number expected had they not been adopted. none of the control group developed SZ, indicating the experiences of adoption was not a factor in SZ

Question 12

conclusion

Answer 12

powerful evidence for the role of genes in SZ. no evidence merged from this study of any role at all for environmental factors in the development of SZ

Question 13

strength of the study

Question 14

strength of the study

Answer 14

samples were similar in terms of average age, size and gender. This enhances the internal validity of the study

Question 15

strength - reliability

Answer 15

there are good controls as the conditions of the sample selection, sources used to asses psychiatric status and independent evaluations made by two psychiatrists blindly

Question 16

weakness

Answer 16

focuses on mothers. 50% of DNA comes from fathers. This significantly reduces the internal validity of the study