Biology of Mood Disorders

Question 1

What regions of the brain are implicated in depression?

Answer 1

Hippcampus and Prefrontal cortex (Cognitive abnormalities, hoplessness, worthelessness), Amygdala (anxiety and fear), Nucleus acumbens (Anhedonia), Hypothalamus (Neurovegetative sx)

Question 2

What is increased in volume and what is decreased in volume in depression?

Answer 2

Increased: Ventricles

Decreased: Caudate, basal ganglia, hippocampus, frontal cortex, gyrus rectus

Question 3

What anatomical finding correlates to MDD/anxiety?

Answer 3

Thinner left ccortex

Question 4

What cortical areas are thicker in MDD?

Answer 4

Orbitofrontal and subgenual cortex

Question 5

What region is responsible for attention and sensory processing in the brain? Is it activated or deactivated in MDD?

Answer 5

Anterior cingulate cortex

Deactivated

Question 6

What are anatomical findings in PTSD patients?

Answer 6

Smaller hippocampus and pregenual cingulate cortex

Question 7

What key region is hyperactive in OCD?

Answer 7

Head of the caudate

Question 8

What are children with a recent GBS infection at risk for?

Answer 8

PANDAS (Pediatric Autoimmune Neuropsychiatric Disorders Associated with Strep); OCD behaviors common

Question 9

How is neuronal activity affected in Panic Disorder?

Answer 9

Fewer GABA receptors–> Increased activity

Question 10

How are NT levels affected in Depression, Mania, and Anxiety (supporting the Monoamine Hypothesis)?

Answer 10

Depression: Decreased 5-HT, dopamine, and NE
Mania: Increased Dopamine
Anxiety: Decreased GABA, increased NE, altered 5-HT

Question 11

What mechanism is impaired in MDD according to the HPA (Hypothalamic Pituitary Adrenal) Axis Hypothesis?

Answer 11

Glucocorticoid feedback mechanism

Question 12

How does neurogenesis play a role in antidepressant actions?

Answer 12

BDNF-mediated increase in dendritic branching and synapse number

Question 13

How does ketamine provide antidepressant effects?

Answer 13

Increase AMPA (GluR1) receptor levels (correlating with the finding that reduced Glutamate neurotransmission causes depression)

Question 14

How do cytokines play a role in depression?

Answer 14

Increased through stress, inflammation, infection, or immunotherapy, and causing alteration in monamines, activating HPA axis, and possibly directly affecting neurons

Question 15

How is estrogen related to depression?

Answer 15

Reduced in women with depression

Question 16

How does maternal care affect depression?

Answer 16

Increased glucocorticoid receptor expression, possible decreased risk for depression

Question 17

Name an epigenetic mechanism that could play a role in depression.

Answer 17

Stress–> Increased histone and DNA methylation –> Reduced transcription of antidepressant genes –> Increased risk of depression

Question 18

Why do histone deacetylase inhibitors (HDAC inhibitors) have antidepressant effects?

Answer 18

Histone acetylation promotes transcription

Question 19

How does ECT treat depression and what is a side effect?

Answer 19

Increased neurogenesis and 5HT receptors (through grand mal seizure)

Side effect: Retrograde Amnesia

Question 20

What main brain region does Deep Brain Stimulation target?

Answer 20

Subgenual Cingulate Cortex (Cg25)