MOOD DISORDERS: ORUC ET AL.

Question 1

What was the aim of the study

Answer 1

• They wanted to investigate whether specific polymorphisms of 2 genes associated with serotonin transmission (5-HT2C and 5-HTT gene) were more common in people with bipolar disorder

Question 2

Describe the sample

Answer 2

• All were from Croatia
• All had Type 1 bipolar disorder
• Opportunity sampling
• 42 in total (25 females and 17 males)
• ages were 31-70 years
• medical records showed that 16 of them has at least 1 first degree relative with a mood disorder
• Had a control group of 40 in total with no family history with a psychiatric diagnosis

Question 3

What type of study was this

Answer 3

• This was a correlational study, It analysed the association between diagnosis of bipolar and specific alleles of the 2 genes.

Question 4

Describe the analysis of blood samples

Answer 4

• They wanted to see which alleles participants were carrying
• 5-HTR2C codes for serotonin receptors. The alleles are called Cys and Ser
• 5-HTT codes for serotonin transporters. The alleles are referred to as 1 and 2

Question 5

State the 3 results from the study

Answer 5

• No significant difference in specific polymorphisms on either genes
• There were some sex differences in allele frequency. There was a difference in the distribution of the S allele of the 5-HTR2C, particularly in females.
• Females with bipolar are more likely to carry allele 1 of the 5-HTT gene than the female controls

Question 6

What did they conclude

Answer 6

The study suggests that females may be more vulnerable to genetic altercations to serotonergic transmission

Question 7

State the 2 methodological strengths

Answer 7

• Participants were carefully assessed to check that they reached the criteria for a diagnosi of bipolar type 1. There were 2 experienced psychiatrists and they used the SADS-L. This is important as the disorder is difficult to diganose as it tends to overlap with other disorders
• Findings strengthen reliability. Oruc replicated the findings of a study by Gutierrez et al who also found no significant difference. This was also seen in Kelsoe et al.

Question 8

State 2 methodological weaknesses

Answer 8

• The small sample size. There were only 3 people with the SS genotype of the 5HTR2C gene. This is important as it means the importance of these genes may have been overlooked.
• Results cannot tell them whether they are at increased risk of the disorder due to several other factors and some particpants may have not been aware of this so leads to psychological harm

Question 9

Application to everyday life:

Answer 9

• Increases the understanding of genetic influences on bipolar. This can help improve drug treatment
• Due to the difficult genetic heterogeneity of the disorder, personalised drug treatments can match the persons genome. This is known as PHARMACOGENOMICS

Question 10

Reductionism v Holism

Answer 10

• It is considered reductionist
• They only examine single genes and specific polymorphisms.
• They cancel out epigenetic factors which consider whether a gene has been expressed or silenced.
• A more holistic examination should look into environmental factors..