What is Seasonal Affective Disorder (SAD)?

Seasonal Affective Disorder (SAD) is a type of depression that is typically caused by the seasons. It’s more prominent in the winter months when temperatures are lower and there’s less sunlight. For this reason, it’s also known as ‘winter depression’, however, it can also be experienced during the summer months too.

In the UK, between 2 and 5 people in every 100 are thought to be affected by the disorder¹ with symptoms starting in September but becoming worse between and November and January; as daylight hours are at their shortest.

We take a look at the symptoms of SAD and what can be done to help lessen the impact on both physical and mental health.

What causes SAD?

Although the exact cause is unknown, SAD is thought to be the result of reduced exposure to sunlight during shorter autumn and winter days. This lack of sunlight stops the hypothalamus in the brain working properly² in certain people and can cause:

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 cause our body clock to go out of sync, leading to tiredness³ and SAD being triggered.

Signs and symptoms of SAD

It’s natural to feel a little lethargic over the winter months, but if someone close to you is acting out of character, they’re more irritable, sleeping during the day or have lost interest in everyday activities, they may be experiencing SAD.

The severity of SAD varies from person-to-person, and for some it can seriously interfere with daily life.

1) Persistent low moods

They may seem more irritable, stressed or more anxious than usual. They’re despondent, give one-word answers or lash out at you over little things, and it’s not just one evening but every day for weeks or months.

2) Less sociable

Your loved one, who may, or may not, usually be outgoing, might be reluctant to spend time with people. Preferring to stay in over socialising.

3) More emotional

They may be more teary or angry. The language they use is negative; they seem to be feeling despair, worthlessness or guilt.

4) Low energy

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

5) Changes in appetite

They may snack more and crave comfort food, like chocolate and high carbohydrate foods which tend to be high in processed sugars. These foods rapidly raise blood sugar, flood our bodies with insulin and leave us feeling low.

Seasonal weight gain is common⁴, 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.

9 ways to help

There are several measures that can help reduce the severity of the symptoms caused by SAD:

1) Eat well

Eat meals packed with vitamins. Fresh fruit and veg are key. For example; oatmeal, omelettes with egg whites, lean chicken or turkey and snacks like popcorn, peanut butter and nuts are all feel-good foods and can actually stimulate serotonin levels.

Avoid coffee, as caffeine has the reverse effect and suppresses serotonin.

2) Stay hydrated

Drinking water throughout the day is important, especially if already feeling lethargic or low, as 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. When you travel to work, and leave, in darkness, a lunchtime walk can be a great solution, as is making outdoor weekend plans; as both times allow you to soak up the sun’s rays.

4) 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.

5) 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 take a holiday in sunnier climes? Plan in something fun to focus your mind on.

6) A good 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, and comfortable haven.
• Introduce a wind-down routine: run a bath, listen to a podcast or read a book. Limit screen time and avoid caffeine – anything that helps you switch off.

7) Adapt your home

Keep your curtains open for as long as possible so your home feels bright and airy.

Light boxes, which simulate sunshine, are a practical solution, proving to be effective for some. They are measured in lux, so the higher the lux, the brighter the light.⁵

Light boxes come in many forms, including alarm clocks, so can easily be integrated into your home. Usually those who experience SAD will sit by a lamp for 30 minutes to an hour every morning, with the aim to boost their serotonin levels and reduce melatonin (the hormone that makes you sleepy).⁵

8) Seeing a GP

If the symptoms of SAD are severely affecting, you or your loved one’s day-to-day life make an appointment with your GP, who may refer you for talking therapies or prescribe antidepressants.

9) Talking therapies

Attending counselling or Cognitive Behavioural Therapy (CBT) sessions for SAD can help, as it encourages people to change the way they think about situations, so thinking positively rather than feeling anxious.

References

1. How common is seasonal affective disorder – Patient Info
2. What causes SAD? - NHS
3. Disrupted body clock - Mind
4. Other symptoms - NHS
5. Light therapy – NHS