Persistent Depressive Disorder Persistent Depressive Disorder Neurobiology & Etiology 2

Question 1

Which genetic polymorphism is most consistently associated with increased vulnerability to depressive disorders including PDD?

Accepted Answer

5-HTTLPR polymorphism in the serotonin transporter gene (SLC6A4)

Answer

The 5-HTTLPR short allele reduces serotonin transporter efficiency and, particularly in interaction with life stress, increases risk for depressive disorders including PDD.

Question 2

Which environmental factor has the strongest evidence for increasing risk of developing persistent depressive disorder?

Accepted Answer

Chronic psychosocial stress and early life adversity

Answer

Chronic psychosocial stress and early life adversity are the most robustly supported environmental risk factors, sensitizing the HPA axis and altering gene expression related to stress regulation.

Question 3

Dysfunction in which prefrontal-limbic circuit is most implicated in the chronic mood dysregulation characteristic of persistent depressive disorder?

Accepted Answer

Anterior cingulate cortex–amygdala circuit

Answer

Reduced anterior cingulate cortex regulation over amygdala reactivity leads to prolonged negative affective states and impaired emotional regulation in PDD.

Question 4

What does the 'kindling hypothesis' propose regarding persistent depressive disorder?

Accepted Answer

Early depressive episodes require major stressors, while later episodes arise with minimal external stress

Answer

The kindling hypothesis proposes that early depressive episodes are triggered by significant life stressors, but over time the neural circuits become sensitized so that episodes occur with progressively less provocation.

Question 5

What role does hyperactivity of the default mode network (DMN) play in persistent depressive disorder?

Accepted Answer

It is associated with rumination and excessive negative self-referential thinking

Answer

Hyperactivity of the DMN in PDD is linked to maladaptive rumination — repetitive, passive focus on distress and its meanings — which perpetuates and deepens depressive states.

Persistent Depressive Disorder Practice Test

Persistent Depressive Disorder Practice Test

Persistent Depressive Disorder Persistent Depressive Disorder Neurobiology & Etiology 2