Imaging Biomarkers and mood disorders

Question 1

Are there currently any biomarkers for mood disorders?

Answer 1

No

Question 2

What are the FDA recommendations for use of biomarkers?

Answer 2

1: 80% predictablitly
2: Aid diagnostics
3: Predict clinical elements (response)
4: Prognostic Biomarkers (risk of reoccurrence)
5: Surrogate endpoint (end of trial)

Question 3

What did a meta-analysis of medication free depressive patients show regarding treatments and their neurological areas?

Answer 3

Pregenual and anterior subgenual cingulate areas = Positive response

Posterior subgenual cingulate, right amygdala striatum and insula = poor response

BUT: underpowered studies

Question 4

What type of studies have been well powered and relatively accurate at predicting drug response?

Answer 4

Machine learning using leave one out system.

Williams et al: Pre-treatment reaction to faces- 75%

Schmaal meta analysis: Emotional faces during current major depression-2 year treatment response- 73%

Korgaonkar et al: DTI (white matter tracks)- 74% treatment response

Question 5

What has been learnt regarding the subgenual and septal areas and mood?

Answer 5

Subgenual area activated when donating to charity, but also guilt and empathy

Septal area: When damaged, less feelings of guilt and pity- activated when donating to charity.

Question 6

How do people with MDD display their anger?

Answer 6

Via non violent irritability and anger toward others related to rejection and thus worthlessness.

Question 7

What has been found regarding the right anterior temporal lobe?

Answer 7

It represents specific social concepts (politeness), protects from overgeneralisation

Question 8

What did Green et al find regarding the connectivity between the anterior temporal lobe and the subgenual lobe?

Answer 8

Hypothesised that since anterior temporal lobe held social concepts and subgenual lobe illicit self blame.

Disruption should be apparent when in self blame, but not in blaming others.

Findings confirmed this.

Question 9

What did Lythe et al find regarding predictability of depression reoccurrence and the subgenual/ anterior temporal connectivity?

Answer 9

Connectivity in this area could predict reoccurrence:

Anterior subgenual and posterior subgenual result in opposite directions.

Machine learning found 25% when including temporal pareintall junction and ventral striatum