Psych: Seasonal Affective Disorder: Free MSRA Podcast

🌞❄️ MSRA DEEP DIVE: Seasonal Affective Disorder (SAD)
In this focused episode, we break down everything you need to know about Seasonal Affective Disorder (SAD) for the MSRA. Based on your revision notes, we’ve pulled out the highest-yield facts — fast, focused, and exam-ready. ✅

🔑 Core Revision Summary

📌 Definition
• A type of recurrent depression with a seasonal pattern
• Most commonly triggered by reduced sunlight in autumn/winter
• Symptoms remit in spring/summer
💡 Mnemonic: "Winter sadness returns annually"

📌 Aetiology
• Reduced light → circadian rhythm disruption
• Altered serotonin (↓) & melatonin (↑)
• Phase-delayed circadian rhythms
• Genetic predisposition (melanopsin gene links)
• Dysfunction in retinohypothalamic tract & pineal gland
💡 Memory hook: "Less Light = Less Serotonin + More Melatonin"

📌 Risk Factors
• Living at higher latitudes 🌍
• Family history of SAD or mood disorders
• Females more commonly affected
• Prior history of depression or bipolar disorder
💡 Quick recall: "Latitude, Lineage, Lady, Low Mood History"

📌 Pathophysiology
• Disrupted brain circuits controlling mood, sleep & body clock
• Dysregulated retinal → hypothalamic → pineal pathways
• ↑ melatonin → lethargy & hypersomnia
• ↓ serotonin → low mood

📌 Differential Diagnoses
• Major depressive disorder
• Bipolar disorder (consider seasonal mania)
• Dysthymia
• Cyclothymia
• PMDD
• Chronic fatigue syndrome
• Hypothyroidism (always rule out!)
• Substance misuse

📌 Epidemiology (UK Focus)
• Prevalence: ~3–8%
• More common in northern UK regions
• Typically starts in young adulthood
• Women > men

📌 Clinical Features
• Core depressive symptoms
• SAD-specific:

• Hypersomnia 😴

• Increased appetite & carb cravings 🍞

• Weight gain ⚖️

• Lethargy, social withdrawal

• Irritability, reduced libido

• Difficulty waking & concentrating
  💡 High-yield clue: "Winter hibernation pattern"

📌 Diagnosis
• Clinical — based on symptom pattern recurring ≥2 consecutive years
• Rule out physical causes (TFTs, glucose, FBC, LFTs, U&Es, B12)
• Structured tools: e.g. SIGH-SAD
💡 Key point: NO specific SAD blood test

📌 Management Approach
1️⃣ Lifestyle: Maximise natural sunlight, morning exposure, exercise 🏃‍♂️
2️⃣ Light Therapy: Bright light boxes (early morning use recommended)
3️⃣ Psychotherapy: CBT, counselling
4️⃣ Medication:

• SSRIs (first-line if required — though evidence limited for SAD specifically)

• Alternatives: Agomelatine, Bupropion, Melatonin
  5️⃣ Combination Therapy: Light + meds or CBT for severe cases
  6️⃣ St. John’s Wort: Possible option for mild-moderate SAD (beware drug interactions)
  💡 Memory ladder: "Sun • Lamp • Talk • Tablets"

📌 Prognosis
• Generally good with proper management
• Recurrence common without ongoing treatment
• Early intervention = better outcomes

📌 Complications
• Major d

Episode Transcript

(00:00):
All right, welcome to the deep dive.
Today we're cracking open a specific set of notes, really
getting into a condition that affects quite a lot of people,
often tied to the seasons changing seasonal affective
disorder or SAD. That's right.
Think of this as your, you know,high yield guided tour
specifically aimed at helping with revision.

(00:20):
Our goal? Unpack everything crucial from
these notes, pull out the absolute must knows and help
make it stick. Yeah, understanding how things
like, well, the environment, particularly light, can impact
mental health is so relevant. And these notes really lay it
out. It's fascinating, that link
between our biology and, well, the world around us it.
Really is. So let's jump straight in.

(00:41):
According to these notes, fundamentally, what is seasonal
affective disorder? What's the sort of core
definition we need to grab onto?Well, at its heart, SAD is
defined as a type of depression that follows a really distinct
seasonal pattern. The notes are clear.
Typically it starts in autumn orwinter and that's linked
directly to less sunlight and then importantly you see the
symptoms go away remit in springand summer.

(01:03):
The key thing for diagnosis is that it involves recurrent
depressive episodes year after year.
Right. OK.
So it's not just feeling a bit down in winter, the winter blue
sort of thing. It's a clinical repeating
pattern tied specifically to theseasons.
Precisely. Yeah, It's often called winter
depression. That's the common name, though
the diagnosis itself has had a bit of a, let's say,

(01:26):
controversial history. It only really got formal
recognition back in the 1980s. And the notes are quite specific
here, pointing out that these recurring episodes, if they get
severe, can potentially lead to hospitalisation.
That really underlines how serious it can be.
The source ties it directly to light changes affecting our
biological clock. And crucially for, you know,

(01:48):
clinical practise, It says it's generally treated like other
types of depression, following NICE guidelines, usually
starting with psychological therapies, maybe considering
SSRI's. Those are the selective
serotonin reuptake inhibitors, common antidepressants, but
advising against routinely usingsleeping tablets.
And it notes, at least in this overview, that the evidence for

(02:09):
light therapy as a routine firststep is seen as limited.
Understood. So the absolute core concept,
the anchor for revision, is basically depression with a
recurrent seasonal pattern. That's the foundation.
Exactly. That's the key.
OK, let's unpack that a bit morethan the notes mention.
Complex causes the ideology. What actually causes sad?

(02:30):
What's going on underneath? Yeah, it's definitely not just
one thing. It's more of a complex mix.
You've got genetic factors, biochemical stuff happening in
the brain, and environmental influence is all playing a part.
And the big environmental 1 is sunlight.
That's the major player highlighted.
Yeah, the reduced sunlight we get in winter.
The thinking is that this lack of light messes with our
circadian rhythms, you know, internal body clock.

(02:53):
And that leads to imbalances in key brain chemicals,
neurotransmitters, especially serotonin and melatonin.
So less light throws off both your body's timing and its
chemistry. That seems pretty fundamental.
It is the notes specifically mentioned phase delayed
circadian rhythms is being involved.
They also touch on a possible genetic predisposition and maybe

(03:14):
abnormalities in the pathway from the eye to the brain's
clock centre. That's the retinal hypothalamic
tract and the pineal gland, which makes melatonin.
And you mentioned genetics playing a role too.
Yes, definitely how sensitive weare.
Delight seems to have a genetic component.
The notes even mentioned links to specific gene mutations, like
in the melanopsin gene, which isinvolved in how our eyes detect

(03:36):
light for regulating those circadian rhythms.
It helps explain why SAD sometimes runs in families.
Right, and this is where it getsreally interesting, doesn't it?
This direct biological connection between something
external like light and our internal mood.
Do the notes link this back to why treatments work?
They absolutely do. It gives the biological why, for
instance, light therapy. The idea is it works precisely

(03:57):
because it influences melatonin secretion and helps boost
serotonin levels. It really reinforces that
serotonin is key here. And the notice also suggests
that things like melatonin receptor agonists, there's a
medication called a gomelatine mentioned, and even just regular
exercise might be effective, which makes sense if you're
targeting these biological pathways.
That really ties it together. So quick revision check.

(04:20):
If you were asked about the mechanism linking winter and
SAD, what key biological pathways from the nose should
definitely be mentioned? You'd absolutely want to hit on
the disruption of circadian rhythms, the impact of reduced
sunlight on serotonin and melatonin levels, the genetic
links we talked about, and potentially issues with those
light sensing pathways from the eye like the Retino hypothalamic

(04:42):
tract. Perfect, got it.
Now thinking about who gets this?
Who's more likely to experience SAT?
What risk factors do the notes outline for us?
OK, the notes give a pretty clear picture.
A big one is living at higher latitudes.
Like further north? Exactly.
The further you are from the equator, the less winter
sunlight you get, basically, andthe higher the risk.

(05:04):
That fits with the epidemiology we'll touch on later.
Makes sense? What else?
Other key factors listed are having a family history of SAD
or other mood disorders like depression or bipolar, being
female it's consistently shown to be more common in women, and
having a personal history of depression or bipolar disorder
yourself. OK, so for a quick memory hook
you could maybe think location, latitude, family history,

(05:29):
gender, female, more common and personal history of mood issues.
That seems to cover the main risk factors from the notes.
That's a good way to summarise them, yeah.
Now, how does all this biology actually translate into changes
in the body? What's the pathophysiology
described in the notes? How does it work physically?
Well, the pathophysiology section really just reinforces
what we discussed under aetiology.

(05:50):
It details how that disrupted brain chemistry and body clock
actually, you know, manifest. It boils down to those changes
in neurotransmitters again, mainly serotonin and melatonin,
and the disruption to the body'sinternal clock, the circadian
rhythm. Can you just quickly recap the
light mechanism again as described in the notes?
Sure. So normally bright light
exposure signals the brain through those special cells in

(06:13):
the retina, the retinal ganglioncells.
This signal tells the pineal gland to suppress melatonin
production, keeps you awake and alert.
But in winter, with less light, that suppression signal is
weaker, so the notes explain. This leads to increased
melatonin, making you feel sleepy, sluggish, and at the
same time decreased serotonin levels.

(06:34):
It's that combination that's thought to drive the mood
changes and throw the circadian rhythm out of whack in SAD.
OK so the simplified version is less winter light leads to more
melatonin plus less serotonin which equals mood changes and a
messed up body clock. That's the core mechanism the
notes are describing, yes. Got it.
OK, changing gear slightly if someone comes in with low mood
specifically in the winter months.

(06:54):
What else could it be? It's not automatically SAD,
right? The notes list several
possibilities. The differential diagnosis.
Absolutely crucial point for assessment.
You have to consider other conditions.
The notes list quite a few. First, major depressive
disorder, just, you know, regular depression that doesn't
necessarily follow that seasonalpattern.
OK, then bipolar I and bipolar 2disorders.

(07:16):
This one's really important. The notes specifically say to
consider bipolar if someone has depression starting in autumn
winter, but then they have periods of hypomania or mania in
spring summer. That seasonal switch is a big
red flag for bipolar. Right, that's a key distinction.
Definitely also on the list, dystomic disorder that's a
milder but more persistent depression, cyclothemic

(07:38):
disorder, milder mood swings, premenstrual dysphoric disorder,
PMDD that's tied to the menstrual cycle phases.
The notes mentioned that specifically.
Then you've got things like chronic fatigue syndrome,
hypothyroidism, and under activefibroid is a classic mimic for
depression symptoms. And of course, you need to
consider substance misuse and alcohol misuse too.

(07:58):
Wow, that's quite a list. So a good memory tip for
differentials might be to think broadly.
Other mood disorders, especiallybipolar, hormonal issues,
thyroid, PMDD, fatigue, substance use, rule those out.
Exactly, clinical assessment is vital to tell them apart.
OK. Moving on to the numbers, what

(08:20):
do the notes tell us about how common SAD is the epidemiology?
Yeah, the notes give some usefulstats.
It's estimated to affect somewhere between 3% and 8% of
the UK population. So not insignificant.
Not at all. And confirming that latitude
risk factor we talked about, it's significantly more common
in northern parts of the UK compared to the South and just

(08:41):
generally more common in countries further away from the
equator, right the. Latitude link is clear in the
numbers then. Absolutely.
It typically tends to start in young adulthood.
And as we mentioned with risk factors, it's more prevalent in
women. The notes also reiterate that
genetic component higher risk ifyou have close relatives with
SAD. And there's an interesting
nuance. They mentioned a seasonal
pattern is actually seen in about 15% of patients who

(09:03):
already have recurrent mood disorders.
So while SAD is its own diagnosis, seasonality can pop
up in people with other types ofrecurrent depression too.
OK, so what's the big picture from the epidemiology?
It's not rare, where you live matters a lot latitude and
there's a clear demographic leantowards younger women.
That sums up the key epidemiological points from the

(09:25):
notes nicely, right? Now let's get really specific.
What does SAD actually look like?
What are the typical signs and symptoms, the clinical features,
and how is it diagnosed based onthis material?
OK, so the notes start with the standard depression symptoms
you'd expect effect things like persistent sadness, low mood,
losing interest or Pletcher and things fatigue, changes in
sleep, changes in appetite or weight, difficulty

(09:48):
concentrating. Maybe you feelings of
hopelessness or worthlessness. The usual suspects for
depression, but then there are the more sort of SAD specific
symptoms. Exactly, and the notes really
highlight these because they canhelp distinguish SAD from non
seasonal depression. These often include increased
sleep duration, hypersomnia, significant cravings for

(10:08):
carbohydrates. Ah, the carb craving.
Hear that a lot? Yes, increased appetite
generally leading to weight gain, social withdrawal, wanting
to hibernate, almost irritability, difficulty waking
up in the morning, decreased energy, feeling lethargic,
decreased libido, and difficultyconcentrating again.
The notes also throw in things like family problems,
tearfulness, headaches, even palpitations as possibilities.

(10:32):
That cluster of increased sleep,carb cravings, increased
appetite and weight gain really does sound different from the
classic picture of depression, which often involves less sleep
and appetite. It really does, and the notes
specifically point to that increased appetite and carb
craving as a characteristic feature that's useful for
diagnosis. But the absolute most critical
diagnostic feature, the one thatoverrides everything else, is

(10:54):
the seasonal pattern. It has to come back each year,
yes. The symptoms must recur and
remit around the same time each year for the diagnosis to stick.
And is there a minimum time for that pattern?
Yes, the diagnostic criteria mentioned state it's based on
those characteristic features ofmild to moderate depression, a
recurring seasonal pattern for at least two consecutive years,

(11:14):
and crucially, ruling out other potential causes for the
symptoms. Two consecutive years?
OK, that's key. Do the notes mention different
types or variants of SAD? They do, they list the most
common 1 autumn inter onset which gets better in spring
summer. There's also a milder form
called sub syndromal SAD. Symptoms are there but less
severe, less impairing. And then there's a much less

(11:36):
common summer onset SAD which actually gets better in the
winter. Interesting.
They also describe a typical progression for the common
winter type. Symptoms often start developing
September through December. It might begin with difficulty
waking up, then progresses to decrease energy and lethargy,
then those characteristic carb cravings, increased appetite,
sleeping, more weight gain, followed by difficulty

(11:58):
concentrating, lower libido and social withdrawal.
OK so a definite memory tip hereseems to be focusing on those
winter hibernation symptoms, thecarb cravings, sleeping more,
weight gain, pulling back socially.
Comparing those to typical non seasonal depression symptoms
like insomnia and loss of appetite is probably a high

(12:20):
yield distinction for revision. Absolutely, and maybe frame it
as a question for yourself. If a patient describes low mood
and fatigue only in winter and specifically mentions wanting
lots of bread and pasta, what diagnosis jumps out?
And why are those food cravings such a useful clue?
According to these notes, that scenario is pretty classic essay
based on this material. Right, that paints a clear

(12:41):
picture. So how do doctors actually
confirm it's SAT? Are there specific tests they
run? What did the notes say about
investigations? The notes are really clear on
this. The diagnosis is primarily based
on clinical assessment. It really relies on taking a
thorough history from the patient, listening carefully,
and assessing their symptoms against the criteria.
There aren't any specific lab tests or imaging scans that can

(13:03):
directly diagnose SAD itself. So no SAD blood test or anything
like that. Nope, nothing like that.
However, investigations are important, but their role is to
rule out other underlying medical conditions that could be
causing or mimicking the symptoms.
OK. So it goes back to that
differential diagnosis list we talked about making sure it's
not something else. Exactly.

(13:23):
The standard investigations listed for ruling out physical
causes include basic blood work,FBC full blood count, U and ES,
urea and electrolytes, LFTS liver function tests, and very
importantly, TFTS thyroid function tests because
hypothyroidism symptoms can overlap significantly.
Right thyroid check is key. Yeah, They also list glucose and

(13:46):
calcium levels and hematinix, which check things like iron and
B12 levels. Then depending on clinical
suspicion, they might do toxicology screens if substance
misuse is a concern. Maybe endocrine or hormone
profiles or even neurological assessments like ACT or MRI scan
or an EEG in specific cases, butthat's less common.
So the tests are really about exclusion, confirming it's not

(14:07):
something else, rather than positively identifying SAD.
Precisely. The diagnosis really hinges on
putting the pieces together, thecharacteristic clinical picture,
that crucial seasonal pattern recurring for at least two
years, and having systematicallyexcluded other possible
explanations. The notes also mentioned that

(14:28):
structured interview tools like something called the Side A's
aid can help standardise the symptom assessment, and one
really crucial point they make for the clinical examination is
to always assess for suicidal ideation and any abnormal coping
mechanisms the person might be using.
Right, Safety first. So what this really means for
diagnosis is it's about careful listening, pattern recognition,

(14:50):
connecting the seasonal dots andspecific symptoms, and ruling
out other stuff. Not about waiting for a lab
result. That's the essential takeaway
for the diagnostic process described to these notes.
Yes. All right.
Great, let's move on to management then.
Once SAD is diagnosed, what do the notes say about how it's
treated? What are the options?
OK, management, the notes break it down into non prescribing and
prescribing approaches and oftenthe non prescribing strategies

(15:12):
are the first line. Makes sense.
What falls under that non prescribing category?
Well, key lifestyle advice is big things like maximising
exposure to natural sunlight, trying to get outside especially
in the morning hours, even on cloudy days.
Regular exercise is consistentlyrecommended, maintaining A
balanced diet and trying to makeindoor environments like home

(15:34):
and work as bright and well lit as possible.
OK, practical lifestyle stuff. And what about light therapy?
That seems like the classic SAD treatment.
Yes, light therapy or phototherapy is definitely in
there. The notes actually listed as
regular management. This typically involves daily
exposure, usually in the morning, to a special bright
light source, a light box or a lamp designed specifically to

(15:55):
mimic sunlight at a certain intense density.
Psychotherapy is also highlighted as important things
like CBT, cognitive behavioural therapy, but also general
counselling or psychodynamic therapy are mentioned.
The goal here is to help patients develop coping
strategies, manage symptoms and maybe address some of the
behavioural changes that come with SAD SO.
Lifestyle, light therapy, talking therapies?

(16:16):
What about medication? Right, prescribing management.
Now this is interesting. The notes explicitly state
there's limited evidence for theeffectiveness of antidepressants
specifically for SAD. That's an important point.
Really, despite it being a form of depression.
Yeah, that's what the notes specify for SAD itself.
However, if medication is deemednecessary, SSR is are mentioned

(16:40):
as the preferred first choice. The notes also list some
alternatives, things like Propranolol, melatonin itself,
or that newer drug, a gomelotine.
And for more severe cases, they suggest that combining light
therapy with antidepressants might be the way to go.
Interesting nuance about the limited evidence for SSRI
specifically in SAD, even thoughthey're the go to if meds are

(17:02):
used. Do the notes compare different
therapies? They touch on it.
They mentioned some studies suggesting CBT might actually
lead to lower depression severity compared to using light
therapy alone, and that researchis ongoing to compare these
approaches more directly. OK, and what about herbal
options? Is Saint John's Wort mentioned?
Yes, it is. Saint John's Wort gets a
mention. It's noted as being effective
for mild to moderate depression in general, and potentially at

(17:25):
least as effective as light therapy for SAD.
But you know, you always have tobe careful about interactions
with other medications with Saint John's Wort.
Any other treatments mentioned? They briefly touch on some
experimental things like using blue light specifically for
therapy and combination approaches like light therapy
plus CBT. An antidepressant called Propion

(17:45):
is specifically suggested as potentially useful for
preventing recurrence, and a goal penalty is highlighted
again as a newer option with a different mechanism, melatonin
agonist and 5HG2C antagonist, that shows potential benefits.
OK, that's quite a range of options.
So a memory strategy for management could be thinking in
layers, start with the lifestylebase, add light therapy and or

(18:06):
psychotherapy. Then consider medication like
SSRI's, remembering that limitedevidence point if needed.
And then maybe think about combinations where those
alternative options like but propion for prevention or
algomelatin. That's a solid framework and the
notes absolutely stressed that the final choice really depends
on how severe the symptoms are, what the patient prefers, and

(18:27):
always, always consulting a healthcare professional for
personalised advice. Right, makes sense.
So what's the overall outlook for someone diagnosed with SAD?
What does the prognosis look like based on these notes?
Generally speaking, the prognosis is described as good
with appropriate treatment. That's the important caveat.
The notes are realistic, though.They state it is a recurrent and

(18:49):
chronic condition. That seasonal pattern tends to
come back year after year if it's not actively managed.
So you have to expect it might return each winter.
Yes, that recurrence is part of the definition really.
However, the positive side is that the notes emphasise with
proper treatment. They specifically call out light
therapy and psychotherapy. Again, people can expect symptom

(19:09):
relief outside of the winter months, and many individuals do
respond well. The key takeaway is that ongoing
management and using preventive strategies are really vital to
lessen the impact when winter comes around.
Good to know it's manageable even if it tends to recur.
OK final area. What happens if SCD isn't
treated or isn't managed well? What are the potential

(19:32):
complications the notes warn about?
Yeah, this is important. If it's left untreated or
managed and adequately, the notes highlight some pretty
significant potential consequences.
It can lead to a really substantial impairment in a
person's quality of life and their ability to function
day-to-day. How might that actually show up
in someone's life? Well, it can manifest as
significant social withdrawal leading to feelings of

(19:53):
isolation. It can cause problems at work or
with studies, occupational issues, and it can put a strain
on relationships. So it can really ripple outwards
and affect multiple parts of life.
It certainly can, yeah. The notes also state that
untreated SAD increases the riskof developing other mental
health disorders down the line, particularly major depressive
disorder becoming non seasonal. And in more severe cases,

(20:17):
untreated SAD can potentially contribute to thoughts of self
harm or even suicide. Those are obviously very serious
potential outcomes. They are and the notes wrap up
this section with a really crucial concluding sentence,
perfect for revision and practise.
Early intervention and getting appropriate treatment are
absolutely essential to prevent these complications and to

(20:38):
promote the person's overall well-being.
Right. So boiling it all down, the
prognosis with treatment is generally positive and it's
manageable, but ignoring SAD or not managing it properly carries
some really significant potential risks to health,
functioning, and overall qualityof life.
That's the critical message, yes.
Yeah, it's definitely a condition that warrants proper

(20:59):
attention and management. Wow, OK, that was a really
thorough deep dive into seasonalaffective disorder, pulling out
all those key details from the notes we've covered.
Well, everything really, from the basic definition, the
fascinating causes involving light and biology, who's most at
risk, how it works in the body, what it actually looks like
symptom wise, especially those key ones like carb cravings.

(21:21):
How it's diagnosed clinically byruling other things out.
The whole range of treatments from lifestyle and light to
therapy and meds. The generally good outlook with
treatment and importantly the serious complications if it's
not addressed, understanding those key features, that
seasonal pattern, those specificsymptoms, that really does feel
like high yield stuff for revision.

(21:42):
It really does highlight that intricate connection between our
environment like light and our internal biology, doesn't it?
SAD is such a clear example of how something seemingly simple
like light exposure can have such a profound effect on our
mental state and health. It really makes you pause and
think about how interconnected we are with the world around us.
That's a very powerful thought to end on.

(22:03):
Definitely food for thought now.If you listening or looking for
more resources to help with yourrevision or maybe want to dive
deep into other topics like thisone, there are some excellent
places you can check out. Yes, absolutely, definitely take
a look at Pass the Mess ray.com.And for some great free
resources specifically designed to help with your studies, head
over to freemsra.com. Yeah, those sites can be really

(22:24):
invaluable for consolidating, understanding and just getting
prepped effectively. We really hope this deep dive
into seasonal affective disorderhas been useful for you.
Feel free to revisit your notes or listen back to this
discussion whenever you need to refresh those key points.
Keep up the great work.