Does Seasonal Affective Disorder Affect Sleep?

What are symptoms of seasonal affective disorder?

If you suspect you might be living with seasonal affective disorder, then you should seek medical advice to find out more. The most common and recognisable seasonal affective disorder symptoms include:

• Persistent low mood
• The loss of pleasure or interest in normal everyday activities
• Feeling irritable
• Feelings of despair, guilt and worthlessness
• Low self-esteem
• Tearfulness
• Feeling stressed or anxious
• A reduction in your sex drive

While these symptoms are also commonly linked to depression, there is also an increase in sleeping activity during the cooler months of the year, with one study reporting that the average person spends an extra 24 hours in bed over the winter months - this could be down to numerous factors.  

To begin with, sleeping in a cooler environment aids a better quality of sleep and whilst there is no scientific-backed advice or reason to sleep more in the winter, it might just be that temperature means you wish to stay cosy for longer - and who can blame you! Another factor is the change in light - symptoms of SAD will increase in the latter months of the year when there is less daylight overall.  

However, for people who suffer from SAD, it’s a different story. The symptoms of SAD are commonly linked to those of depression, and there is a strong link between depression and sleeping. Whilst some people who suffer from depressive symptoms need more sleep, others will find that insomnia plays a part in the disorder, too. This can range on a spectrum, meaning one day you may be more lethargic than another day, and other days, more restless.  

How seasonal affective disorder affects sleep

Sleeplessness affects everyone from time to time, but for people suffering from seasonal affective disorder, it might be a more regular occurrence. Seasonal changes can affect sleep as waking up during the winter months is a challenge for most people - days get shorter and mornings are colder so there’s no wonder we see sleep pattern changes. However, SAD sufferers might experience a more distorted sleep cycle overall during this time. 

Going into further detail, let’s delve into the question: does SAD affect sleep? Simply put, yes - suffering from seasonal affective disorder has the ability to play a huge part in our regular sleep cycle. So, why does it affect our sleep patterns? 

Insomnia and CBT-I

People who suffer from SAD will be no stranger to insomnia. This is because direct links to anxiety, depression and general nervousness can alter someone’s thought pattern, making it harder for them to fall asleep at night. CBT-I is a type of cognitive-behavioural therapy that links directly to the treatment of insomnia. 

Data suggests that using psychotherapy to address, analyse, and manage these "unhelpful ideas" about sleep could lead to better therapies for seasonal affective disorder.

Data suggests that using psychotherapy to address, analyse, and manage these "unhelpful ideas" about sleep could lead to better therapies for seasonal affective disorder. 

What causes seasonal affective disorder?

The main cause of SAD is being exposed to less light, but it can be caused by numerous factors, some of which might be relevant to you but not everyone. Whilst some people experience it mildly, others have more severe symptoms of SAD.  

There is some evidence that the further you live from the equator, the more likely you are to suffer from symptoms of SAD due to fewer daylight hours in winter and a higher variation in daylight hours between seasons. Another factor that might make someone more susceptible to SAD, is their genes - if a parent suffers from SAD then your chances of getting SAD are much higher.  

Chemical imbalance is the direct effect of too little light in the day and causes symptoms of seasonal affective disorder, too. Sufferers that find they are sleeping more in the winter might have an overproduction of melatonin at the wrong time points. Melatonin is the hormone that sets our inner clock and aligns it to the rhythm of night and day. During the day, melatonin levels are elevated whilst at night more melatonin has no extra effect. Sufferers often have abnormally low levels of serotonin, which affects mood, appetite and sleep, and is the common denominator in causing a depressive-like state of mind.  

How does seasonal affective disorder get diagnosed? 

If you suspect that you are suffering from SAD, it is important to seek medical advice. Once you have spoken with a professional, there are several ways in which you might be diagnosed, or tested, for seasonal affective disorder.  

Physical exam: To begin with, your doctor or medical advisor may do a physical exam. This would involve asking questions about your physical health, too. 

Lab tests: After that, you may be required to have a blood test taken. Your doctor might carry out complete blood count (CBC) or test your thyroid to make sure it's functioning properly. 

Psychological evaluation: It is likely that if you are suffering from symptoms of SAD, then you will undergo a psychological evaluation, which will involve asking questions about your mood and general well-being.  

What you can do to relieve symptoms of seasonal affective disorder  

Seasonal affective disorder (SAD) is a type of depression that is related to changes in seasons. Several studies suggest that a lack of sunlight contributes to seasonal affective disorder. Hence, it was derived that getting more light often helps to treat SAD, which can be achieved with light therapy.  

How does light therapy help SAD? 

Bright light works by stimulating cells in the retina that connect to the hypothalamus (a part of the brain that helps control the body's internal clock). By using light therapy, the cells in the eyes signal 'day' to our master clock in the hypothalamus. This helps to regulate all the processes linked to the inner clock, like hormonal secretion. As production from serotonin, cortisol and melatonin are directly linked (all mood-affecting hormones), we feel better as a result. Melatonin is a hormone produced largely at night by the pineal gland and has long been linked to the regulation of the sleep-wake cycle. 

The duration of light exposure matters as well 

One study found that an improvement in depressive symptoms of SAD could be seen after an initial session of 20 minutes to light intensity only. Further to this, another study found that devices emitting as little as 98-700 lux 45 minutes a day will decrease SAD symptoms within a week as compared to the standard treatment of 3000-5000 lux 1h/day. In general, electric light has a much lower intensity compared to daylight (even on a cloudy winter day), therefore seeking the outside might also help.

That being said, although light therapy can potentially be effective in treating SAD, a debate on the light intensity needed to induce a positive response in patients suffering from SAD is ongoing. There are various steps you can do on your own in addition to speaking with a professional about SAD treatments. 

Exercise  

Low-intensity exercise, such as 10 minutes of walking per day, can improve mental and physical health. Exercise can be as effective as an antidepressant for some people with mild to moderate seasonal affective disorder. 

Support  

It's important to realise that you're not alone if you're suffering from SAD. Spend time with other people, talk about what you're going through, and avoid isolating yourself. 

Being kind to yourself 

Symptoms of SAD may improve gradually, so trust in the process that you set up for yourself.  

If light therapy and self-care aren't enough to alleviate your symptoms, Cognitive Behavioural Therapy (CBT) or medication may be used. If you're still having trouble sleeping and are experiencing depression symptoms, talk to your doctor. 

Having the right sleeping environment

If you struggle with sleeping, then it is important to consider adopting a sleep pattern and nighttime routine. Understanding sleep wellness and sleep hygiene and habits are important when thinking about your own bedtime routine.  

Takeaway 

Whilst seasonal affective disorder is a common illness, it is still valid and needs to be treated properly to ensure you don’t suffer from the unpleasant side effects. If you are experiencing a change in your sleeping habits, low mood, or insomnia, then contact a professional for guidance.  

Recommendations by the experts at Emma  

We recommend using a Chronolamp by Philips which is a smart lamp that allows people to use light beneficially to find an individually optimal sleep-wake pattern, fight seasonal shortcomings in light, and to align the body's inner clock with external demands. 

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