18.3 Bipolar disorders Flashcards
are there sex differences in the incidence of bipolar
no
what is hypomania
creduced need for sleep, high energy, positive affect
- talkative, energetic, impulsive, positive, very confident
- can be very fun to be around and very effective in some jobs
what is mania (5 symptoms on top of hypomania)
extreme form of hypomania (same symptoms but more intense) - additional symptoms 1. delusions of grandeur 2. overconfidence 3. impulsivity 4. distractibility 5 psychosis
what do people exhibit during bouts of full blown mania
unbridled enthusiasm, outflow of incessant chatter that jumps between topics, lofty goals,
what does the confidence and grandiosity, coupled with higher energy, distractibility and impulsiveness tend to cause in mania
series of disasters
- unfinished projects
- unpaid bills
- broken relationships
what is type 2 bipolar
bipolar that ranges from depression to hypomania
what is bipolar type 1
bipolar that ranges from depression tp hypomania and mania
explain the case of SB
used to have that depression, but started feeling very good
- sleeping less than 3hrs per night
- elevated mood
- sociable and charasmatic
- could read faster, understand materials he’d found difficult before
- became very productive - most of the material for his Thesis was developed during this time
- type 2 bipolar at the time
- got worse
- less than 2 hours of sleep per night
- sometimes would go days without sleep
- read incessantly, began to feel he had unique talents and insights, developed intense theories - delusions of grandee -TYPE 1
- mood jumped off a cliff, began to feel alone and rejected, sjicidal thoughts
- all while not sleeping and experiencing delusions of grandeur
what is a mixed state
a state characterized by symptoms of both severe depression and mania
how long to transitions from depression to mania tend to take
weeks to months on average
what do we call bipolar with more than 4 or more mood episodes per year
rapid cycling
how heritable is bipolar
twin studies estimate between 80 and 90%
what have genome sequencing studies of those with bipolar found
many genes are involved, some that code for calcium channels and proteins found at the nodes of randivier
what are mood stabilizers
(ideally) drugs that effectively treat depression or mania without increasing the risk of mania or depression respectively
why is it important to protect against mood episodes in bipolar
the episodes become more severe and more frequent if left untreated
what is the mechanism of mood stabilizers
up for debate, but many have shown to be effective in epilepsy and schizophrenia…
what is lithium
a simple metallic ion that was the first drug found to act as a mood stabilizer
explain the investigations of John Cade that uncovered lithium
infected guinea pigs with the urine of psychiatric inpatients
- manic patients was the most toxic
- wanted to uncover which chemical caused this
- injected guinea pigs with urea and found that it was toxic, but not as toxic as the urine of manic patients
- potentially uric acid - injected both urea and lithium urate into guinea pigs
- contrary to predictions, lithium rate protected the pigs against the toxicity of urea
- then injected some pigs with both urea and lithium carbonate
- check to see if it was lithium or or the uric acid that was protective
- it was he lithium
- hypothesized manic patients had lower levels of lithium than non-manics
what did Cades’ initial findings of the effects of lithium on psychology and behaviour uncover - what do we now know about this finding
that lithium carbonate claimed guinea pigs
- at these doses, it produces extreme nausea - the pigs weren’t calm they were ill
- anyways, gave a bunch of lithium to patients
what did Cades’ initial findings of the effects of lithium in humans uncover
gave lithium to 10 patients with mania, 6 with schiz and 3 w depression
- lithium helped those with mania, some were even discharged at a time when this was VERY rare
why did it take so long for lithium to enter widespread use
can’t patent a simple compound so no mmkoney in it
how effective is lithium
- currently believed to be the best mood stabilizer
how effective are mood stabilizers (1), and what are their side effects? (4) what do these cause?
some are effective in mania, some in depression, some in both
- never eliminate all symptoms
- many of them produce negative side effects
1. weight gain
2. tremor
3. blurred vision
4. dizziness - encourage non-adherence
what are the consistent findings of fMRI studies in those with bipolar (overall, plus (5 specific areas))
- overall reduction in grey matter volume
- specific brain structures are smaller
1. medial PFC
2. left anterior cingulate gyrus
3, left superior temporal gyrus
4. certain prefrontal regions
5. hippocampus
what have metaanalysis of fMRI studies of those with bipolar uncovered? (3 activation, 1 connectivity)
atypical activation in... 1. frontal cortex 2. medial temp lobe structures 3. basal ganglia atypical functional connectivity bvetween some of these structures in a variety of cognitive states
what 2 factor have hindered the ability to understand the mechanism of bipolar
- lack of understanding of the mechanisms of mood stabilizers
2, lack of adequate animal models
what do we know about the causal mechanisms of bipolar
there are several physiological disturbances that may contribute to onset and maintenance
- HPA axis dysregulation
- disruptions in circadian rhythms in those with bipolar and their on bipolar relatives (depression)
- alterations to GABA, glut and monoamine neurotransmission
- evidence that BDNF levels are lower in those with bipolar when both depression OR manic
