emotions are a critical part of the
human experience we laugh and we cry but
sometimes our emotions get out of hand
sometimes the sadness we feel isn't just
the Blues sometimes it's depression it
turns out the depression is more than
just feeling kind of sad it's actually a
neurological condition that can really
affect your everyday life depression is
common it's actually the leading cause
of disability among American adults
according to the National Institutes for
mental health in 2015 about 16 million
people had at least one major depressive
episode just during that year
that's almost 7 percent of the u.s.
population depression comes in many
forms but most of those forms have the
same symptoms they just vary in severity
and length common symptoms of depression
include sadness feeling empty hopeless
or worthless fatigue changes in sleeping
patterns irritability changes in
appetite and thoughts of suicide when a
person experiences these symptoms for at
least 2 weeks and it's interfering with
their daily life it's called the major
depressive disorder this is the one you
probably think of when you think of
depression but if those symptoms go on
for more than two years
it's called persistent depressive
disorder and depression can be brought
on by specific situations and life
changes like postpartum depression which
can occur after a person has a baby and
seasonal affective disorder when the
lack of sunlight in the fall and winter
can trigger symptoms because depression
can look like normal sadness and because
it's not always obvious what caused it
sometimes it's hard for people to
believe that it's real that's why some
people argue that if you just try hard
enough you can break the cycle you're in
control of your own emotions so you can
choose to feel better
anyone who's suffered from depression
knows that that's not true we're still
trying to figure out what causes it and
what exactly it does to our brains and
it's important for doctors and
scientists to keep working at
understanding the conditions so they can
get patients back on their feet there's
definitely a genetic component
if your parent or sibling has the
condition it's more likely that you
might end up with it too but it can also
be linked to environmental factors
things like abuse neglect and severe
life stressors like financial
instability or a death in the family all
make it more likely that a person might
develop depression so what's actually
going on in your brain up until recently
scientists were pretty sure the
Depression was caused by an imbalance of
certain chemicals within the brain
dubbed the mono aming hypothesis of
depression
this theory said that a lack of
neurotransmitters like serotonin and
dopamine - chemicals associated with
feelings of pleasure and reward would
lead to depression this theory is
supported by a couple of things first
scientists found that people with a
particular genetic variation in the gene
that codes for the serotonin receptor
5-htt are more susceptible to depression
after stressful life events when
compared to people who don't have that
mutation this mutation is thought to
reduce the production of serotonin
receptors in the brain leading to a
decrease in serotonin signaling there's
also evidence mostly from post-mortem
brains that people with depression have
changes in the dopamine signaling in
their brains some research has found
that in patients with a family history
of depression deliberately reducing
levels of the proteins required to make
neurotransmitters like serotonin and
dopamine does decrease their mood and
finally there's the fact that
antidepressant medications like
selective serotonin reuptake inhibitors
or SSRIs work these medications function
by altering the release of serotonin at
the synapse adjusting serotonin
signaling throughout the brain but
scientists are no longer positive that
depression is a direct result of a
simple chemical imbalance some of the
research and treatments have been
inconsistent with that idea and the
condition is really complex so
researchers are also exploring a lot of
other possible explanations
brain imaging studies have found that
patients with depression generally have
less gray matter in several different
brain regions like the cingulate cortex
the hippocampus and the amygdala gray
matter made up mostly of neuronal cell
bodies dendrites synapses and glia is
the place where most neuronal signaling
happens so changes in gray matter volume
can affect all kinds of things like
emotions memory and decision making this
has led some scientists to theorize the
depression is more related to structural
differences than neurochemical ones
basically depression shrinks the parts
of the brain that are important for
controlling our emotions and making
choices to take care of ourselves making
it hard for patients to recover from
feelings of sadness some scientists
think the depression could be related to
changes in brain plasticity that's the
process that lets your neurons change
and adapt their signaling in response to
new information it might even be related
to a reduction in neurogenesis the
growth of new brain cells even though
it's uncommon in the adult brain there
are some brain regions that create and
connect new cells throughout our lives
this theory points out that chronic
stress has a negative impact on
neuroplasticity and a similar change in
neuroplasticity is seen in patients with
depression treating the condition with
antidepressants might increase the
formation of new brain cells and
depressed patients taking
antidepressants have higher levels of
BDNF a chemical that supports
neurogenesis yet another theory about
depression links it to our immune system
research has found that patients with
depression have unusually high levels of
cytokines small proteins that play a big
role in the inflammatory response that
kicks off when your body is responding
to an injury cytokines are involved in
sickness behavior you know how when
you're sick you're usually not very
hungry and have trouble concentrating
and
really just want to sleep a whole bunch
Hey those symptoms sound an awful lot
like depression don't they this theory
proposes that high cytokine levels
caused by stress can impact normal
neurotransmitter signaling leading to
the symptoms of depression this is why
some doctors may encourage their
patients to take anti-inflammatory
medications like ibuprofen alongside an
antidepressant therapy can be very
effective at treating depression about
one of every three people will find that
cognitive behavioral therapy alone can
improve their symptoms mica is making a
video all about the psychology of
depression and how its treated in a
clinical setting there are also a number
of antidepressants available on the
market medications like SSRIs SNRIs and
tricyclic antidepressants function by
increasing levels of neurotransmitters
like serotonin and norepinephrine at the
synapse monoamine oxidase inhibitors or
mao is block the enzymes that break down
those same neurotransmitters in all
cases they're primarily aimed at
enhancing neuronal signaling involving
those neurotransmitters but not every
antidepressant is the same even
different SSRIs can affect different
people in different ways and it takes a
few weeks for the medications to really
start having an effect sometimes it
takes a while to find the right
medication which can be stressful and
frustrating for a patient who's really
needing help because depression is
pretty common and because it's complex
it could be that the underlying cause of
depression varies from person to person
whatever the cause scientists are
getting closer and closer to finding
better solutions and luckily treatments
do exist they're not perfect but they
can definitely help that's why it's so
important to keep working on answering
these questions even when some
medications are already available on the
market if you or a loved one has
experienced depression I hope that this
video has helped you understand the
condition a bit better please check out
the description box below for resources
on understanding and living with
depression thanks for watching this
episode of neuro transmissions if you
liked it hit that thumbs up button and
subscribe so you can catch Micah's video
all about how psychologists treat
depression with therapy you can also
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help support us making more videos like
this in the future until our next
transmission I'm alie astrocyte over now
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