depression and bipolar Flashcards
describe a depressive disorder
sad, empty, irritable mood + physical + cognitive concerns
diagnostic criteria for mdd
depressed mood + diminisehd interest or pleasure in activities & at least 3 other symptoms (eg sleep/weight/energy changes)
symptoms = significant distress/impariement, + not attributable to phys effects or med condition
what is the monoamine hypothesis
antihypertensives could precipitate depression
(dec presynaptic serotonin + norepinephrine)
antimycobacterials improve mood?
(inhibite monoamine oxidase => dec amin degradation)
low serotonin may underline depression
monoamine hypothesis now?
overismplistic? genetic evidence, but inconsistent study findings (metabolites)
is it just fkn wrong? new study says no serotonin impact
endocrinology patho in MDD
HPA axis is dysfunctional
inc cortisol predicts risk of MDD development
high CRH in CSF
neurogenesis patho in mdd
brain derived neurotrophic factor
(sustains neurons, inc dendritic branching + synapse numner)
dec = neuronal atrophy + death, dec dendritic branching (hippocampus)
low levels in depression
bdnf production is suppressed by cortisol
brain connectivity patho mdd
central exec network = working memory
default mode network = reflection
salience network = switch between the two
network dysfunction/disconnection in mdd
hypoconnectivity in CEN (dorsolateral prefrontal cortex),
hyperconnectivity in fmn (posterior cingulate and medial prefrontal cortex)
novel pharm treatments for mdd
non-oral ketamine = blocks nmda receptor for ionotropic glutatmate
rapidly improved symptoms
number of mechanisms eg downstream inc in ampa signalling -> neurogenesis
novel non-pharm treatments mdd
transcranial mangetic stim
magnetic pulse on scull, turns parts brain on/off
normalises connectivity
stim left dlpfc
in dmn and cen
what are bipolar disorders
bridge between depressive _ psychotic disorders
shifts from high - low mood
bp1 = classic manic depressive disorder
how diagnose bipolar 1
1 manic episode
irritable mood, high energy for 1 week + 3 other symptoms (eg dec sleep, dcitrability)
monoamines for bipolar and depression (ntsm)
permissive theory:
low norepinephrine + dopamine + serotonin => depression
high norepinephrine + dopamine, low serotonin -=> mania
but dopamine antagonists and agonists improve state of mania,
brain structure + activity patho bipolar disorder
low gray matter fronto-insular cortex + left anterior cingulate (internal awareness + emotional processxing)
inc act medial temporal lobe (hippocampus emotiona tasks
low act inferior frontal gyrus (cognitive tasks = mania)
pharm treatment for bipolar
lithium = dec neuronal excit _ synaptic glutamate %, inc serotonin, reg Ca2+ influx
=? reduce excitation + stim inhib
lithium response = heritable
narrow therapeutic window
reg blood test (but trying to target genetic and saliva sampling)
treatment is dependent on experience of mania or depressive symptoms
