Neurobiology of Mood Disorders Flashcards
What do appetitive/approach systems do?
Mediate seeking and approach behaviours (incl. pleasure).
What parts of the brain are involved in approach behaviours?
- ascending dopamine systems – mesolimbic/corIcal projecIon
- ventral striatum
- dorsal striatum (movement)
- amygdala (conditioning / learning)
- anterior cingulate (attention / conflict /response selection)
- orbitofrontal cortex (relative reward preference / rule learning)
What do aversive/defensive systems do?
Promote survival in the event of threat (fear/pain).
What parts of the brain are involved in promoting survival in the event of threat?
- ascending serotonin systems
- NA / CRF / peptide transmiters
- central nucleus of amygdala
- hippocampus
- ventroanterior and medial hypothalamus
- periaqueductal gray matter
Give an explanation of depression.
Altered sensitivity/accuracy of brain systems evaluating rewards and cues predicting rewards within the environment
Give an explanation of anxiety.
Altered sensitivity/accuracy of brain systems evaluating threats and cues predicting threats within the environment
What is the lifetime prevalence of depression?
16%
Is depression more common in men or women? By how much?
Twice as common in women
By how much is risk of psychiatric admission increased in the 30 days following childbirth?
7x
What % of women experience blues in the first 2 weeks?
75%
What % of women develop MDD in first 3-6 months?
10%
How often does ‘puerperal psychosis’ occur?
1 in 500 deliveries
What is the risk of recurrence with subsequent deliveries?
1/3
______________ has complex polygenic influences associated with multiple variants and environmental interactions
Depression
What is the final hormone in the HPA axis?
Cortisol
Cortisol level is elevated in what?
Urine, saliva
What happens to the secretion of ACTH in depression?
INCREASES
What happens to the secretion of cortisol?
INCREASES
What is increased in CSF in major depression?
CRH
What happens to the adrenal glands in major depression?
Enlarged
50-70% fail to suppress CORT production following DEX
TRUE
What are the final hormones in the HPT axis?
Thyroid - T3 and T4
What % of people with major depression show changes in the HPT axis?
20-30%
What is increased in CSF in major depression that its CRH?
TRH
What happens to TSH response to TRH?
It is blunted in 20-25% of pts, despite normal basal TSH, T3 and T4
During almost all studies of emotion, what is there co-activation of?
AIC and ACC.
What are there parallel descending projections to?
Sensory and motor nuclei in the brainstem
What does the Anterior Insular Cortex have dense connectivity with?
The anterior cingulate cortex
What type of region is the Anterior Insular Cortex?
A visceral sensory region
On structural imaging, what can be seen in bipolar disorder?
Reduced grey matter volume – Brodmann Area 24 (anterior cingulate)
What have post-mortem studies of someone with bipolar shown?
Reduced glilal cell numbers with NORMAL neuronal numbers in Brodmann Area 24 and OfC
Outline what is seen on functional imaging of someone with bipolar?
- Increased metabolism in amygdala (L), correlates with outcome.
- Reduced metabolism OfC and Medial Ventral pfC, decreased FA of CTI in anterior cingulate
What do approach/appetitive behaviours do?
Mediate seeking and approach behaviours (incl. pleasure).
