Seasonal Affective Disorder (SAD)

7 July 2023

Seasonal Affective Disorder (SAD) is a type of seasonal depression with a pattern – it starts and stops with the seasons but is more prominent in the winter months. For this reason, it’s also known as ‘winter depression’.

In the UK, about 3 people in every 100 are affected by the disorder between the months of September and April, and there’s a chance that someone close to you may be experiencing the symptoms.1

However, SAD doesn’t need to cast a shadow on your relationship or home life; as knowing the signs to look out for, and how to support your loved one if you’re worried, will make for brighter days all year round – whatever the weather.

What causes SAD?

SAD is caused by reduced exposure to sunlight during shorter autumn and winter days, which affects the brain from working properly in certain people. Here’s why:

1. Overproduction of melatonin

This hormone, which makes us feel sleepy, may be disrupted by a change of season. Melatonin tends to be overproduced in people that experience SAD

2. Lowered serotonin levels

This brain chemical affects mood, appetite and sleep, with links to feelings of depression. A drop in serotonin can therefore throw these out of kilter 

3. Changes in internal body clock

Our bodies use sunlight to help determine when we wake up, so reduced levels can trigger SAD.2 

Signs and symptoms of SAD to look out for 

It’s natural to feel a little lethargic over the winter months, but if someone close to you is acting out of character and there’s an atmosphere at home, they may be experiencing SAD. It’s important to remember that the severity of SAD varies from person-to-person, and for some it can seriously interfere with daily life.

If you’re worried, rest assured that help is available – and your support will go a long way towards overcoming the condition. 

Firstly, see if you can spot the following signs in your loved one: 

1. Persistent low moods

They may seem more irritable, stressed or anxious than usual. You feel the awkwardness of prolonged silences, when you’re used to animated conversation. Instead, they’re despondent, give one-word answers or lash out at you over little, trivial things. It’s not just one evening, but every day – for weeks, then months.

2. Less sociable

Your loved one – who may, or may not, usually be outgoing – might be reluctant to spend time with people. You cancel plans with friends, or go out alone, because your other half prefers staying in over socialising.

3. More emotional

They may be showing more extreme emotions – they’re teary or angry. The language they use is negative; they seem to be feeling despair, worthlessness and / or guilt. This happens when a lack of sunlight affects our hormones.

4. Loss of interest

They seem disinterested in normal, everyday activities. Their libido may be affected too.

5. Low energy

They struggle to wake up in the morning, then feel lethargic and keen to sleep throughout the day.

6. Changes in appetite

They may snack a lot and crave comfort food, like chocolate and high carbohydrate foods like white bread and rice. These tend to be high in processed sugars, so rapidly raise blood sugar, flood our bodies with insulin and leave us feeling low. Seasonal weight gain is therefore common, especially in winter when it’s hard to find motivation to exercise or venture outside. 

The last two symptoms are important when it comes to differentiating between SAD and non-seasonal depression. While people with SAD commonly eat more and sleep more, those experiencing non-seasonal depression typically eat less and sleep less. 

10 ways to help:

There are several measures you can recommend or explore to support your loved one: 

Eat well

To counteract their hunger pangs, take the reins in the kitchen and whip up delicious meals packed with vitamins. Yes, fresh fruit and veg are key – but certain carbohydrates can actually stimulate serotonin levels.

For example; oatmeal, omelettes with egg whites, lean chicken or turkey and delicious snacks like popcorn, peanut butter and nuts are all feel-good foods. Avoid coffee, as caffeine has the reverse effect and suppresses serotonin. 

Stay hydrated

Drinking water throughout the day is important, especially if your loved one is already feeling lethargic or low. Dehydration can increase fatigue and headaches.3 

Step into the daylight

Natural daylight supports the body’s circadian clock and makes falling asleep at night easier. It’s easy to feel at a loss when you, and your loved one, travel into work – and leave – in darkness. A lunchtime walk is a great solution – why don’t you challenge them to see how many steps they can do in a day?

If you work together or nearby, meet to do this together and break up the working day. Suggest outdoor plans at the weekend, like a romantic woodland stroll to soak up the sun’s rays.

Encourage exercise

Whether it’s walking to work rather than taking the bus, a long cycle at the weekend or housework, finding opportunities to exercise and raise your heartrate can work wonders on energy levels and overall mood.

Always have plans to look forward to

There’s nothing more exciting than an upcoming fun day or night out. Why not surprise your partner or family member with tickets to see their favourite musician? Or a little holiday in sunnier climes? You know them best, so think carefully about activities they’d enjoy – and close friends or family to potentially bring into the mix, if you feel they’d be up for it.

Work out their stress triggers

Don’t be afraid to ask them how they’re feeling. If they snap, that’s OK. Just reassure them that you’re there to offer support and a fresh perspective. You might start to notice patterns in their behaviour that can help you take steps to manage the SAD symptoms.

A sleep routine

Quality sleep is crucial for mental and physical wellbeing – all the more so when shorter daylight hours change our internal body clocks, potentially resulting in SAD symptoms.

Create a calm sleeping environment by turning your room into a dark, quiet, clean and comfortable haven. Introduce a lovely wind-down routine; you could run a bath for them, listen to a podcast or read in each other’s company. Limiting screen time and avoiding caffeine goes a long way towards helping you both switch off 

Adapt your home

Keep your curtains open for as long as possible so your home feels bright and airy – you want to maximise their exposure to daylight. Light boxes, which simulate sunshine, are a practical solution, proving to be effective for some.

Most light boxes emit an intensity of 10,000 lux and treatment will take 30 minutes to one hour a day. To put this into context, the intensity of a summer day can be 100,000 lux.2

Your loved one should start to feel a difference within three to four days. Light boxes come in many forms, including alarm clocks, so can easily be integrated into your home.

Try talking therapies

Attending counselling or Cognitive Behavioural Therapy (CBT) sessions for SAD can completely change you’re their outlook, encouraging them to think positively rather than feel anxious.

Suggest an initial chat with an expert and offer to join. Sessions like these are a popular solution that can make such a difference.

Suggest seeing a GP

If their SAD symptoms are starting to cripple them, or strategies you hoped would work simply aren’t making a difference, why not suggest visiting a medical professional?

In severe cases of SAD, antidepressants may be prescribed. If they experience SAD every year, it’s worth seeing your GP well in advance of the winter months; antidepressants, if needed, are best taken before symptoms appear then continued through until spring.

It’s completely natural to worry about your loved one if they’re not themselves or you’re feeling the tension in your relationship. Don’t underestimate the power of your support, though; by taking these steps, you can help banish the winter blues. 


  1. Seasonal Affective Disorder (SAD) - Royal College of Psychiatrists
  2. Seasonal Affective Disorder: An overview of assessment and treatment approaches – National Library of Medicine
  3. Effects of changes in water intake on mood of high and low drinkers: National Library of Medicine

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