Key Study: Oruč et al.

Question 1

Context

Oruč et al.

Answer 1

• previous research shows that genetics is at least partly responsible for BPD development
• serotonin, dopamine, noradrenaline - 3 neurotransmitters thought to be connected to BPD

Question 2

Main theories

Oruč et al.

Answer 2

1. Genetic Theory
2. sexual dimorphism

Question 3

Genetic Theory

Oruč et al.

Answer 3

• mental disorders thought to have a genetic basis
• first degree relatives share 50% of DNA
• connections can be made between first degree relatives because of transmission of genetic information

Question 4

Sexual dimorphism

Oruč et al.

Answer 4

• serotonin is sexually dimorphic
• polymorphism in serotonin receptor 2c and serotonin transporter 5-HTT genes potentially responsible for risk of BPD in females

Question 5

Theory: serotonin receptor 2c & serotonin transporter 5-HTT genes

Oruč et al.

Answer 5

• alterations in serotonin receptor 2c and serotonin transporter 5-HTT genes may lead to disturbance of specific biochemical pathways linked to depressive disorders

Question 6

General neurochemical explanations

Oruč et al.

Answer 6

• abnormality in neurochemicals lead to mental health disorders e.g. BPD
• too much/too little neurochemicals affects functioning of brain → affects emotional regulation

Question 7

Aims

Oruč et al.

Answer 7

investigate whether genes coding for serotonin receptor 2c and serotonin transporter 5-HTT genes
could be involved in susceptibility to BPD

Question 8

Hypotheses

Oruč et al.

Answer 8

Polymorphisms in serotonin receptor 2c and serotonin transporter 5-HTT genes are responsible for susceptibility to Bipolar Disorder (BPD)

Question 9

Research method

Oruč et al.

Answer 9

• Natural experiment
• DNA Testing

Question 10

Experimental design

Oruč et al.

Answer 10

Matched-pairs

control group matched to experimental group in age and sex

Question 11

Experimental sample size

Oruč et al.

Answer 11

42

25 Female ; 17 Male

Question 12

Sample demographics

Oruč et al.

Answer 12

• from 2 psychiatric hospitals in Croatia
• 31 - 70 yrs
• diagnosed with BPD Type 1

Question 13

Procedure

Oruč et al.

Answer 13

DNA Testing → test for polymorphisms in serotonin receptor 2c and serotonin transporter 5-HTT genes

Question 14

Data collection techniques

Oruč et al.

Answer 14

DNA testing

Question 15

Results

Oruč et al.

Answer 15

• 38% of BPD group had at least one first degree relative diagnosed with Major Affective Disorder
• no signficant associations of BPD to polymorphisms in serotonin receptor 2c and serotonin transporter 5-HTT genes

Question 16

Conclusions

Oruč et al.

Answer 16

1. sexual dimorphism of serotonin
2. those with family history of mood disorders no more likely to have polymorphisms in serotonin receptor 2c and serotonin transporter 5-HTT genes than others

Question 17

Control group size

Oruč et al.

Answer 17

40

Question 18

Control group demographics

Oruč et al.

Answer 18

• no personal/family history for mental health disorders
• matched for age and sex