Now, we’re going to talk about depression,
one of the most common
mood disorders that’s
extremely important o
know about for your exam.
So what is depression?
Well, it’s an episode of dysphoria
associated with more than a low mood,
but also associated with a loss
of interest in activities.
The epidemiology for depression
includes a lifetime prevalence of 15%.
The onset can be at any age.
However, young adults and
elderly are at particular risk.
The prevalence in 18 to
is actually three-fold
higher than in other groups.
Females will experience nearly three-fold
higher rates of depression than men,
and there’s actually no ethnic
or socioeconomic difference.
However, a very important
note to keep in mind is that
while depression can occur
many minorities are actually
more likely to be misdiagnosed
and instead of being accurately diagnosed
with depression or a mood disorder,
they may be labeled as
an important note to consider.
And about two-thirds of all depressed
patients will contemplate suicide,
up to 10 to 15%
actually commit suicide
and only half of those patients
with major depressive disorder
will actually ever
So most people go
Do you know who described
depression as anger turned inwards?
That was Sigmund Freud.
He actually wrote about this concept in his
1917 paper called Morning and Melancholia.
Here, he described depression as
introjected rage over object loss.
Let me give you a clinical case example.
Consider a 40-year-old woman.
She’s been struggling with
feeling unloved at home,
dissatisfied in her career and taken
advantage of by her extended family.
She’s had long standing trouble with her
sleep, appetite, sense of self-worth,
energy, and she’s lost interest
in all of her hobbies.
When she learns that
her husband has been
secretly taking money from
her personal account,
this woman becomes enraged
and furious at her husband.
Then, she takes her own life.
The perfect example of
anger turned inwards.
The cause of depression
is not exactly known.
But we do believe that
environmental and psychosocial
factors play a role.
Let’s consider this chart here.
There’s a lot of information, this all
describes the pathogenesis of depression.
So what is decreased in
patients with depression?
Well, we know that drugs that
increase the availability
of serotonin, noradrenaline and dopamine will
actually alleviate symptoms of depression
and therefore, we think that all of
these neurotransmitters are reduced
in people who have depression.
Let’s talk a little bit about
the monoamine hypothesis.
This postulates that antidepressants
increase the amount
of noradrenaline or norepinephrine
and serotonin in the brain
primarily by increasing the concentration
of these neurotransmitters in the synapse
and by down regulation of
their postsynaptic receptors.
Another question to post to you is
what neurotransmitter is decreased
in the cerebrospinal fluid
in patients with depression?
That answer is serotonin.
When it comes to
what two main factors
in this category
do you know about that are
associated with depression?
The answer is high cortisol.
And this is from hyperactivity of the
hypothalamic pituitary adrenal access.
Also, thyroid disorders,
very important to know,
are associated with
There are also psychosocial factors,
but before we get to those,
let’s talk a little bit more about what
the hippocampus has to do with cortisol.
Well, it tends to be especially sensitive
to the neurotoxic properties of cortisol,
which is actually elevated
during times of stress,
the hippocampal volume may actually
be correlated to a depressed episode,
so we know with increased stress
comes higher cortisol levels,
and then depression, and
changes to the hippocampus.
Now, how can family affect
Well, a few things.
Loss of a parent before the age of 11
can be associated with depression.
But a stable family and stable
such as good attachments
to early caregivers,
support network of family and friends
are all really good prognostic factors.
Genetics also play a role
in developing depression.
We tend to think that depression can be
inherited and passed along in the generations.
Usually, if somebody’s
presenting with depression,
it’s going to be likely that someone
in their family also has had depression.
First degree relatives are two to three
times more likely to have major depression.