SAD and Winter Blues for VetMed - and what we can do about it...
- Vet Empowered
- Feb 20
- 7 min read
Every year, somewhere around the clocks going back, something shifts for many of us. The mornings get harder. The motivation dips.
You come home in the dark, you leave in the dark, and somewhere in between you're existing under fluorescent lights wondering why you feel like you're operating at about 60% capacity.
You're not imagining it. And you're not being dramatic.
This blog draws on a session from the WellVet archive recorded in 2020, delivered by Dr. Claire Gillvray - GP, psychiatrist, GB Ironman triathlete, and someone who has spent a long time thinking about the intersection of mental and physical health. It was recorded during a winter that, as Claire put it at the time, "has hit our mental health like no other year." Some of the context has changed since then.
The biology hasn't.
We've summarised the key insights here and added our own thoughts where it felt useful. This is for information only - nothing here replaces a conversation with your own GP or healthcare provider.
First, let's talk about what Seasonal Affective Disorder (SAD) is
Seasonal Affective Disorder (SAD) is a real clinical diagnosis - but it's also a term that gets used pretty loosely. True SAD affects around 6–9% of the UK population and involves recurring depressive episodes that follow a seasonal pattern, year after year.
But a much larger proportion of us - closer to a third - experience what Claire calls "winter blues": a meaningful dip in mood, energy, and motivation during the darker months that doesn't quite reach the clinical threshold but still has a real impact on daily life.
As Claire put it: "This is something for everybody, whether you feel that you have that as a disorder or not, because we all have mental health and we all struggle in the winter."
The symptoms of both overlap significantly with depression: low mood, fatigue, difficulty getting up, social withdrawal, loss of enjoyment in things you'd normally like, irritability, increased carbohydrate cravings, and disrupted sleep. One feature that tends to be more pronounced in winter-related low mood is oversleeping — that hibernation-like heaviness where you could sleep for ten hours and still feel exhausted. If that sounds familiar, you're in good company.
It's also worth knowing that SAD is four times more common in women, particularly during reproductive years. That's not a coincidence — hormonal fluctuations interact with the seasonal biology in ways we're still understanding. If you've ever felt like winter hits you harder than the people around you, there may be very real physiological reasons for that.
The biology bit (it's actually quite useful to know)
Three things are working against you in winter, and understanding them helps.
Light.
This is the big one. Daylight triggers cortisol release in the morning — that's what wakes your system up. As the days shorten, you may find yourself going to work in the dark and coming home in the dark, spending the hours in between under artificial lighting.
Claire described this plainly: "If you're working in a veterinary practice with little in the way of windows, you could go the whole day without seeing any daylight."
This disrupts melatonin release, throws your circadian rhythm off, and affects everything from your blood pressure to your glucose regulation. The knock-on effects compound quickly.
Vitamin D.
Claire highlighted vitamin D deficiency as one of the most widespread nutritional deficiencies globally, with some population studies putting prevalence as high as 40%. — and it gets worse in winter for obvious reasons.
We produce vitamin D through skin exposure to sunlight, and in the UK between October and March there simply isn't enough UVB radiation to maintain levels adequately. Low vitamin D is consistently found in people with SAD and is associated with fatigue, low mood, and reduced immune function. If you have darker skin, you're at higher risk of deficiency year-round.
Serotonin.
In winter, the body produces more of a protein called SERT — serotonin transporter — which essentially mops up available serotonin before it can do its job. The result is lower active serotonin across the board, affecting mood, sleep, and appetite. This is the same system that SSRIs act on, which is why some people find seasonal medication genuinely helpful.
What you can actually do about the Winter Blues and SAD as a veterinary professional
None of this is your fault. But some of it is within your control, and that's worth focusing on.
Get light in your eyes early.
Claire was clear on this: "If we know that the biggest trigger for our melatonin and our body clock is to get daylight in the morning — if there's any way of making that happen, then do."
Morning light, even on an overcast UK day, is far more effective at regulating your circadian rhythm than any light box. Light boxes are NICE-recommended and a reasonable option if daylight isn't accessible, but as Claire noted, "nothing really replaces daylight — it's the best thing if you can get it." Even sitting near a window makes a measurable difference.
Keep your sleep timing consistent.
This one is uncomfortable because it means reining in the weekend lie-in, but your body clock doesn't work on a weekly schedule. Claire used jet lag as a useful frame: "You can't go one night to bed at 11 and expect to sleep if every other night in the week you're going to bed at one in the morning." Every deviation creates a lag, and your body is always playing catch-up.
Consider vitamin D supplementation.
Maintaining vitamin D through diet alone is genuinely difficult. Claire noted that oily fish, mushrooms, and some fortified cereals are sources, but absorption is limited — and the official recommendation of half an hour of midday sun on exposed skin is, as she put it, "the time that you're working."
Around 800 IU (international units) per day is a commonly cited starting point for general supplementation, but individual needs vary significantly. If you think you might be deficient — particularly if you have darker skin, get limited sun exposure, or have symptoms — it's worth getting your levels checked and discussing supplementation with your GP or healthcare provider.
For a thorough clinical overview, the NIH Office of Dietary Supplements has an excellent resource: https://ods.od.nih.gov/factsheets/VitaminD-HealthProfessional/
Prioritise social connection — especially when you don't feel like it.
Claire cited this as the top factor in mood research, and it's consistently the one most likely to slide when we're already low.
She also made a point that we think about a lot at Vet Empowered: "Sometimes we expect people to be asking for help, but not everybody is able to ask for help or necessarily wants to ask."
When someone is in a depressive dip, they often can't reach out. The people around them need to reach in. A walk with a friend ticks more boxes than almost anything else on this list.
Move, in whatever way works for you.
The research Claire cited suggests 90 minutes of movement a week as a meaningful baseline for mental health benefit. The most important factor for sustaining it is enjoyment — not what everyone else is doing, but what you actually like. As she put it: "Just because everyone's running doesn't mean you need to be a runner. That is just definitely not everybody's cup of tea."
Watch your alcohol intake.
Claire named this directly and so will we. "It is a coping strategy for a lot of people," she said, "and it's worth being aware that it is a depressant. You might find that it's making you sleep better, but we actually know that the quality of sleep is worse, and it is actually depressing you and taking away your serotonin."
If it's become a default way of winding down after a hard shift, it's worth noticing that — not from a place of judgment, but because it's likely making the very thing you're trying to ease a little bit worse.
If you've noticed that alcohol has become more of a regular fixture than you'd like, you're not alone and there's no judgment here. It's one of the most common ways people in high-pressure roles manage stress — and one of the least talked about. A good starting point is just noticing the pattern. If you'd like further support with that, you can explore resources through Drinkaware (drinkaware.co.uk) or Alcohol Change UK (alcoholchange.org.uk), or speak with a healthcare professional.
A note on medication
If your mood reliably dips every winter and lifts every spring, that seasonal pattern is clinically useful information.
As Claire explained: "A lot of people will, if they find that they have a seasonal quality to their mood, just take a serotonin medication through the winter — for four to six months — and that's enough to boost those serotonin levels."
This is a conversation worth having with your GP. There's nothing weak or dramatic about it.
The bigger picture
We wanted to end on something Claire said at the start of this session that has stayed with us: "I use mental health as a positive word rather than a negative word." That framing matters. Winter is hard for most of us, and the biology is real. Naming that — to yourself and to the people around you — is a reasonable place to start.
If you're working shifts, if you're a parent of small children, if you're in a demanding clinical role that leaves little room for the things on this list — we know.
We're not handing you a checklist and expecting it to transform January. But even one thing, done consistently, is worth more than the perfect routine you never quite start.
Watch Claire's full session from the WellVet archive here:
Useful resources
VetLife — free, confidential support for the veterinary community vetlife.org.uk | Helpline: 0303 040 2551
NHS: Seasonal Affective Disorder nhs.uk/mental-health/conditions/seasonal-affective-disorder-sad/overview/
Mind: SAD mind.org.uk/information-support/types-of-mental-health-problems/seasonal-affective-disorder-sad/
NICE guidance on SAD nice.org.uk/guidance/cg90
NIH Office of Dietary Supplements: Vitamin D (clinical overview) ods.od.nih.gov/factsheets/VitaminD-HealthProfessional/
Moving Medicine — evidence on the benefits of physical activity movingmedicine.ac.uk
This blog draws on insights from a WellVet archive session recorded in 2020, now hosted by Vet Empowered. The content is for general information only and does not constitute medical advice. Please speak to your GP or healthcare provider about anything specific to your own health.
