Neurobiology of Mood Disorders

Question 1

What substance is involved in appetitive systems?

Answer 1

Dopamine

Question 2

What substance is involved in aversive systems?

Answer 2

serotonin (5-hydroxytryptamine)

Question 3

Name some functions of disordered appetitive functioning in depression

Answer 3

• difficulty identifying rewarding stimuli
• reduced contact with previously rewarding stimuli
• increased contact with aversive stimuli
• overall reduction of behaviour
• moveless, eat less, lose weight, less libido

Question 4

Name some functions of disordered appetitive functioning in hypomania/mania

Answer 4

previously neutral sImuli become “rewarding”
• increased exploraIon / overall acIvity
• increased “appeIte” for food, acIvity, sex etc…
• intolerant of “aversion” / boredom
• intolerant of frustraIon
• elevated / elated mood?

Question 5

Is depression more common in women or men?

Answer 5

twice as common in women

Question 6

What type of life events can typically precipitate a depressive episode

Answer 6

adverse events

‘exit events’ - separations, losses

Question 7

What percentage of women experience the ‘blues’ post pregnancy?

Answer 7

75%

Question 8

What is puerperal psychosis?

Answer 8

Postpartum psychosis, sometimes referred to as puerperal psychosis or postnatal onset bipolar disorder, is a serious psychiatric illness. It can affect one in 500 to 1000 women who have a baby.

Question 9

Puerperal psychosis is normal, and managed in the community conservatively - true/false

Answer 9

False - this is a psychiatric EMERGENCY requiring hospital care

Question 10

What genetic factors influence depression?

Answer 10

Depression – as with other psychiatric disorders – complex polygenic influences associated with multiple variants and
environmental interactions

Question 11

What effects does major depression have on the Hypothalamic Pituitary Adrenal Axis?

Answer 11

increased ACTH
increased Cortisol
elevated urinary cortisol
enlarged adrenal glands

50-70% fail dexamethasone suppression test

Question 12

What effects does major depression have one the Hypothalamic Pituitary Thyroid axis?

Answer 12

Increases TRH

TSH response blunted in a quarter despite normal basal levels.

Question 13

What are the key regions of the brain involved in mood disorders?

Answer 13

• Orbital prefrontal cortex
• Ventromedial prefrontal cortex
• Dorsolateral prefrontal cortex
• Hippocampus and Amygdala
• Anterior cingulate cortex

Question 14

What effect does major depression have on hippocampal volume?

Answer 14

reduced in proportion with number of days of depression

Question 15

What role do the anterior cingulate cortex and anterior insular cortex play in emotion?

Answer 15

engender feeling (awareness) and motivation (agency) associated with emotion

Question 16

What grey matter deficit is seen in bipolar disorder?

Answer 16

reduced grey matter volume in anterior cingulate cortex - Brodmann 24