00:03
A 40 year old male with a past medical history
of major depression presents to the clinic
interested in joining a research study on
depression-related sleep disturbances.
00:14
He has had two episodes of major
depression within the last two years,
one occuring during the summer and then the other
occuring during the winter of the other year.
00:25
He has been noncompliant
with medications
and has a strong desire to treat his
condition with non-pharmacological methods.
00:34
He would like to be enrolled into this study that
utilizes polysomnography to record sleep-wave patterns.
00:42
Which of the following findings is likely associated
with this patient's psychiatric condition?
Answer choice (A) -
increased total REM sleep
(B)- increased slow wave sleep
(C) - late morning awakenings
(D) - increased
REM sleep latency
and (E) - associated
with a seasonal pattern
Take a moment to come
to your own conclusion.
01:09
Now let's go through the
question characteristics here.
01:12
We got a patient - he's
got major depression.
01:15
This classically falls under
behavioral science/psychiatry
Now this is a 2-step question.
01:21
Meaning we have to 1- come to a conclusion and then
go one step deeper to come to the correct answer choice.
01:28
And in this case, we need to use
the stem to know our answer.
01:33
We can't just read the last
sentence and know what we want.
01:36
We have to rely on components
of the clinical vignette.
01:40
Now let's walk through
the answer choices here.
01:42
Now step one, what we need to do
is determine the relationship
between the patient's underlying
psychiatric condition and sleep.
01:52
Okay, so this patient has major depression disorder,
which is actually typically associated with
either excess sleep, which is called hypersomnia
or lack of sleep which is called insomnia.
02:05
Now it's interesting, medications
for major depressive disorder
are actually known to
cause sleep disturbances.
02:14
Now there is no specific information in the clinical
vignette that is reported regarding sleep disturbances,
so we have to then make our own differential which includes
sleep disturbances related to major depressive disorder,
and sleep disorders related to major
depressive disorder medications.
02:38
Now this makes it a little bit easier because
this patient was noted to be noncompliant
with major depressive disorder medication
which really narrows down our differential
down to sleep disturbances related to
major depressive disorder itself.
02:53
Now step two here, we need to determine
what sleep phase is most likely associated
with major depressive
disorder sleep disturbances.
03:04
And we'll look at our answer choices.
03:06
Now, what we know is that in patients
that have major depressive disorder,
they have increased total REM sleep,
and that's the correct answer,
answer choice (A) -
increased total REM sleep.
03:21
Now let's go through some high-yield facts
that we learned from this question.
03:25
Let's talk about major depressive disorder.
03:27
Now, major depressive disorder is a psychiatric condition characterised by recurrent depressive episodes
lasting at least 2 weeks each.
03:37
During which the patient experiences,
either severe depressive mood or anhedonia.
03:44
Now, the diagnostic criteria for major
depressive disorder is described in DSM-IV-TR,
and it states that at least one of the two
symptoms of depressive mood or anhedonia
must be present for the diagnosis
of major depressive disorder.
04:03
Now, major depressive disorder affects
over 200 million people globally,
and is nealry twice as
common in women than in men.
04:13
Now major depressive disorder
sleep disturbances are typically
very early awakenings with the inability
to fall back asleep - insomnia,
or excessive sleepiness - hypersomnia
Now, treatment of major depressive disorder is generally
a combination of both psychotherapy and medication,
but it really depends
case to case per patient.
04:38
Now let's talk about the phases of
sleep, also another high-yield topic.
04:43
There are 5 phases of sleep.
04:45
The first four phases are non-rapid
eye phases, which are called NREM
and the fifth phase is called REM,
or the rapid eye movement phase.
04:56
The phases actually are
pretty simple to understand.
04:59
They progress cyclically from NREM1 all the
way through REM, and then they begin back at NREM1.
05:07
and each cycle lasts roughly
about 90 to 120 minutes.
05:11
Now, the phases are characterized as follows:
NREM1 is light sleep, NREM2 is light sleep, NREM3 is
deep sleep, NREM4 is deep sleep, and then you have REM.
05:25
Now during REM, brain waves actually mimic activity
during the waking state with your eyes closed
but your eyes will actually
move rapidly from side to side.