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

COMT Val158Met polymorphism

Answer

APOE ε4 allele

Answer

MTHFR C677T variant

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

Urban living

Answer

High-altitude residence

Answer

Rotating shift work schedules

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

Prefrontal cortex–basal ganglia circuit

Answer

Prefrontal cortex–cerebellum circuit

Answer

Insular cortex–thalamic circuit

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

Each episode increases resilience against future mood disturbances

Answer

Genetic vulnerability diminishes with each successive episode

Answer

Medication sensitivity decreases with illness duration

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

It causes attention deficits by suppressing task-relevant networks

Answer

It reduces connectivity between prefrontal and limbic areas

Answer

It promotes hypervigilance to external threat cues

Question 6

Which metabolic finding in frontal and limbic brain regions has been documented in neuroimaging studies of persistent depressive disorder?

Accepted Answer

Dysregulated glucose metabolism, with reduced activity in prefrontal areas

Answer

Hypoglycemia confined to the thalamus

Answer

Elevated metabolic activity throughout the limbic system

Answer

No significant metabolic differences from healthy controls

Question 7

Which sleep architecture abnormality is most commonly observed in persistent depressive disorder?

Accepted Answer

Shortened REM latency and reduced slow-wave sleep

Answer

Increased slow-wave sleep and delayed REM onset

Answer

Complete absence of REM sleep cycles

Answer

Increased total sleep time with fragmented NREM cycles