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lithium is the third element on the
periodic table
but it's also so much more than that
lithium and its compounds are used to
make everything from cell phone
batteries to airplane parts to
pacemakers
and one compound lithium carbonate is
also used in psychiatric medicine
most commonly to treat patients with
bipolar disorder if it's surprising that
the same element used in batteries would
be good for your brain
yes but the stranger thing is even
though we've been using this treatment
for
decades we're still learning exactly how
and why it works doctors started using
lithium compounds to treat neurological
conditions
way back in the mid-1800s then in 1949
an australian psychiatrist named john
kade discovered that lithium carbonate
in particular could treat the extreme
mood swings symptomatic of bipolar
disorder over the next 70 years this
compound which
we'll just call lithium from now on went
on to become a first-line treatment
and now the world health organization
considers it one of the world's most
essential medicines
having an effective drug treatment for
bipolar disorder is
great researchers estimate that around
45 million people worldwide have it
and while there are a few slightly
different subtypes of bipolar disorder
it can cause someone's mood to fluctuate
between depression and euphoric mania or
between depression
and a slightly less extreme manic
episode all in all though this can be
disruptive to
everyday life and on average it can also
shorten someone's life expectancy by 9
to 17 years
so having a drug like lithium is
incredibly important but unfortunately
it
doesn't work for everyone a 2017 study
found that only one-third of patients
can be treated effectively with lithium
alone
for everyone else it either doesn't work
or has to be paired with another drug to
get results
and for the longest time we just didn't
know why or
why lithium works period but finally
we've started to put the pieces together
for one starting around the 1970s
research has
gradually revealed that lithium can help
stabilize magnesium levels in our bodies
magnesium plays an important role in
neurological health by helping
electrical signals move from one neuron
to another and studies show that
patients with bipolar disorder symptoms
often have irregular levels of it
so the fact that lithium can stabilize
magnesium levels means it could improve
how signals are transmitted through the
nervous system but
that doesn't seem to be the only way it
works like the authors of a more recent
2018
study discovered that while lithium may
play nice with magnesium
it gets competitive with sodium normally
sodium binds with certain types of
g-protein-coupled receptors or
gpcrs which are proteins found on cell
membranes that help
activate cell responses humans have more
than 1 000 types of gpcrs and they help
regulate everything from our sense of
taste to the levels of serotonin and
dopamine in our brains but in this 2018
study
scientists found that lithium can give
sodium the boot it turns out that when
lithium binds with compatible gpcrs
instead of sodium
it can deactivate them but that can
actually be a good thing
we're still learning a lot about how
these receptors work but we do know that
they can be hyperactive in patients with
bipolar disorder
and some gpcrs in our brain control
levels of chemicals like serotonin and
noradrenaline
which scientists believe are key players
in bipolar disorder
so if lithium can inactivate some of
these hyperactive receptors
that might be another reason it can
treat symptoms so well so
overall there are still some things to
pin down but we're finally starting to
get a sense of why lithium works at
all and in 2017 another study came out
that might even shed some light on why
it only helps in some cases
in this paper the researchers focused on
mapping how lithium works on a molecular
level
and in doing so they discovered that
bipolar disorder can be caused by a
protein involved
in nerve cell communication called crmp2
in patients with bipolar disorder that
didn't respond to lithium treatment
researchers found that crmp2 was much
more active than in patients who did
respond to lithium
this matters for a couple of reasons for
one by understanding how lithium
interacts with these proteins
doctors could better predict which
patients might respond well to lithium
treatment but also these results could
mean that bipolar disorder isn't always
caused by changes to someone's genetic
code it could also be the result of how
proteins like crmp2 are treated
inside cells in the future information
like this could lead to the development
of new drugs
and even diagnostic tests and since it
takes the average person
eight years to get diagnosed with
bipolar disorder a diagnostic test could
really speed things up
of course this wouldn't apply to all
cases and it wouldn't address
other complications with diagnoses like
the stigma around bipolar disorder
but for some people it would be a step
in the right direction
even though we've been studying lithium
carbonate for decades we've only
finally begun to figure out some of its
secrets but the more we learn about this
compound
the more we can understand how bipolar
disorder works and how to develop
effective treatments for those who need
them thanks for watching this episode of
scishow psych
and a huge shout out to the patrons on
patreon who make this show possible our
patrons decided we should make scishow
psych a few years ago and now
they're the ones helping us explore the
complexities of the human brain so to
all of our patrons
thank you and if you'd like to learn
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