Other slides in this set

Slide 2

Preview of page 2

Here's a taster:

GENETIC FACTORS ­ FAMILY STUDIES
If the incidence of schizophrenia is higher in families it
suggests there is a genetic cause of Schizophrenia.
Gottesman (1991) :
Relationship Incidence rate
General population 1%
If the sibling has schizophrenia 8%
If one parent has schizophrenia 16%
If both parents have schizophrenia 46%
These results establish that schizophrenia is more common
among biological relatives of a schizophrenic individual…read more

Slide 3

Preview of page 3

Here's a taster:

GENETIC FACTORS ­ TWIN STUDIES
Twin studies are a way to investigate the contributions that genetic
and environmental influences have on twins concordance rate of
schizophrenia.
Gottesman and Shields (1972) found that the probability of a twin
having schizophrenia if its twin has the disorder:
Then looked at another 40
studies in 1991 and found
Relationship Incidence rate in 1972 Incidence rate in 1991
Monozygotic Twins 42% 48%
Dizygygotic twins 9% 17%…read more

Slide 4

Preview of page 4

Here's a taster:

GENETIC FACTORS ­ ADOPTION STUDIES
· The third way to indicate the influence of genetics on the
incident rate of schizophrenia is to study genetically related
people who are reared apart.
· This would help to disentangle genetic and environmental
factors
Tienan (2000) studied schizophrenia incident rates with
adoptees who's mothers either had or didn't have
schizophrenia.
Adoptee with schizophrenic mother: 7%
Adoptee with non schizophrenic mother: 2%…read more

Slide 5

Preview of page 5

Here's a taster:

GENETIC FACTORS EVALUATION ­ FAMILY
STUDIES
· The main criticism of family studies is
that there are environmental factors
that may affect the results.
· Studies have shown that a family with However, there is a lot of
highly expressed emotion makes evidence supporting the
idea that schizophrenia
schizophrenia more likely
does run in families
· The findings of Gottesman's study
may be due to the individual being
unable to cope with the stress due to
their family and this has triggered
schizophrenia.…read more

Slide 6

Preview of page 6

Here's a taster:

GENETIC FACTORS EVALUATION ­ TWIN
STUDIES
· There is no doubt that there is a greater concordance in
monozygotic twins than dizygotic twins
· As twins from the studies were brought up together the
difference between the two types of twins was thought to be
due to genetics
· However Joseph (2004) found that in many areas
monozygotic twins are brought up and treated more similarly
than dizygotic twins
· This questions whether the findings were due to the effect of
genes or the environmental upbringing…read more

Slide 7

Preview of page 7
Preview of page 7

Slide 8

Preview of page 8
Preview of page 8

Slide 9

Preview of page 9
Preview of page 9

Slide 10

Preview of page 10
Preview of page 10

Comments

Kirsty Stimpson

All your resources for psychology are really useful! thank you :)

Similar Psychology resources:

See all Psychology resources »See all resources »