Genetics and Biology

Question 1

What is behaviour genetic studies?

Answer 1

A field of research which studies variation among individuals within traits to distinguish the genetic contribution.

Question 2

What is a heritability estimate?

Answer 2

how much of the variation in a given trait (e.g. mental disorder) can be attributed to genetic variation.

Question 3

what is a concordance rate in biological research?

Answer 3

the % of cases in which both members of a twin pair have a particular attribute (e.g. a mental disorder)

Question 4

What proportion of adoptees with a biological family history of schizophrenia developed schizophrenia later in life?

Answer 4

5/47 (10.6%) of the index group compared 0/50 of matched controls were diagnosed with schizophrenia later in life.

Question 5

d: polymorphic gene

Answer 5

a gene with different variants, which (commonly) occur in the population

Question 6

d: polygenic

Answer 6

a factor that is influenced by more than 1 gene (eg height, depression etc)

Question 7

How is the hypothalamus related to depression?

Answer 7

Dysregulation or hyperactivity of the HPA axis is well characterised in depression (and stress). Involved in many signs of depression e.g. disordered day-night rhythm, lack of reward feelings, disturbed eating, sex, and cognition

Question 8

How is the frontal lobe associated with depression?

Answer 8

Lower activation and smaller volume associated with major depression (linked with rigid thinking, impulsivity etc.)

Question 9

How is the hypothalamic pituitary adrenal system associated with depression?

Answer 9

The hypothalamic-pituitary adrenal (HPA) system responds to stressors, leading to the release of stress hormones (e.g. cortisol)

Question 10

How is the hippocampus associated with depression?

Answer 10

Links perceptual systems with memory (especially LTM)
Encodes emotional context of events from the amygdala
Reduced hippocampal volume, especially if recurrent / early onset

Question 11

What does the thalamus do?

Answer 11

Critical hub for relaying incoming sensory info for cognition and emotion processing

Question 12

How is the thalamus associated with psychosis?

Answer 12

Reduced volume in schizophrenia may explain changes in sensory experience and attribution.

Question 13

What does the hippocampus do?

Answer 13

A role in memory’s links with perceptual and context info

Question 14

How is the hippocampus associated with psychosis?

Answer 14

Reduced volume in psychosis
Reduced activity linked with visual hallucinations

Question 15

What is the function of the amygdala?

Answer 15

Generates emotional responses from senses, especially fear/anger.

Question 16

How is the amygdala associated with psychosis?

Answer 16

Smaller volume linked to psychosis
Increased hippocampus-amygdala connectivity found in paranoid schizophrenia

Question 17

What is the function of the temporal lobes?

Answer 17

Processing speech/sounds, emotions, visual memories

Question 18

How is the temporal lobe associated with psychosis?

Answer 18

Grey matter density and activation affected in individuals with auditory hallucinations

Question 19

Which mental disorder did Caspi et al (2003) find was linked with variants if a secretion transporter gene (5-HTT)?

Answer 19

Depression

Question 20

d: genotype

Answer 20

genetic code itself, the genetic constitution of an individual organism.

Question 21

d: phenotype

Answer 21

gene expression

Question 22

What is DNA methylation?

Answer 22

A common epigenetic mechanism which alters the activity of the DNA, and this may be subject to environmental influence (e.g. stressors, hormones, diet, drugs…)

Question 23

How does early life stress relate to dopamine expression?

Answer 23

Mice who had experienced early life stress showed suppression of ‘dopamine expression’ gene

Question 24

Altering the glucocortisoid sensitivity gene expression helped which mental disorder?

Answer 24

PTSD