How Seasonal Affective Disorder Affects Your Sleep

Feb 8, 2023 | Blog, Sleep Disorders, Sleep Tips

While the holidays present plenty of opportunities for fun and festivities, the fewer hours of daylight and cooler temperatures can bring with them a shift in mood and a drop in energy. However, seasonal affective disorder (SAD) is more than just feeling blue. It can dramatically affect how you function from day to day as well as how you sleep at night.  

Keep reading to learn what SAD is, how to fight it, and how to say goodbye to restless nights.

What is Seasonal Affective Disorder?

Seasonal affective disorder, or SAD, is similar to a mood disorder like depression. It occurs in around 0.5 to 3 percent of the general population.1

While depression can happen at any time for any reason, SAD typically occurs at the same time each year. It is most prominent during the fall and winter months.2 Although it tends to resolve itself as warmer months approach, SAD can quickly become overwhelming and debilitating if not addressed.


If you are experiencing the following, you may be struggling with SAD:2

  • Feeling sad or listless
  • Losing interest in hobbies
  • Feeling sluggish with low energy
  • Sleeping too much
  • Overeating leading to weight gain
  • Difficulty concentrating
  • Experiencing feelings of hopelessness
  • Having thoughts of not wanting to live


Although a specific cause remains unknown, these factors may play a role in SAD:3

  • The sudden reduction of light during fall and winter may lead to SAD as the lack of sunlight can disrupt the body’s circadian rhythm and cause depression.
  • This reduced sunlight can also cause a drop in the brain chemical serotonin. Due to serotonin’s link to mood, it is thought to play a role in depression and other health conditions. 
  • The change in season to the fall and winter months can disrupt the body’s melatonin levels which play a critical part in both mood and sleep patterns.

How does SAD affect sleep?

People with SAD often feel extremely sleepy during the day despite sleeping longer than usual at night. In fact, those with SAD tend to sleep two hours longer at night in the winter than in summer.4 This sleepiness may lead to an increased urge to nap throughout the day, however, napping may not relieve feelings of exhaustion. Unfortunately, sleeping too much can be just as harmful as not sleeping enough.

People with SAD also have nightmares more frequently than those without it. One study actually found that 16% of participants with SAD had nightmares compared with only 2.4% of participants not diagnosed with the disorder.5

How to conquer SAD

There are many different routes you can take when looking to tackle SAD and get back to living and sleeping well. The following is a mixture of recommended treatments as well as lifestyle changes you can start putting into practice today.

Light Therapy

Light therapy, otherwise known as phototherapy, consists of sitting next to a special light box that allows you to be exposed to bright light within an hour of waking up. By mimicking natural outdoor light exposure, it elicits positive changes in the brain chemicals linked to mood.

Light therapy typically starts working within a few days to weeks after beginning treatment. Research is limited, so before considering light therapy, consult your healthcare provider.6

Cognitive Behavioral Therapy

A type of psychotherapy, or talk therapy, called cognitive behavioral therapy can help you:7

  • Form healthy coping mechanisms.
  • Recognize and address negative thought patterns.
  • Learn how to effectively manage stress.
  • Begin building healthy habits.


For some people with SAD, particularly those with severe symptoms, the use of antidepressants is recommended. As a preventive measure, your healthcare provider may suggest taking antidepressants prior to the time of year that your symptoms typically start.

Finding the right medication for you may be a lengthier process than expected. It is also important to note that it may take several weeks before you experience the full benefits of taking medication.8

Lifestyle Changes

Making these changes can help set you up for success at night:

  • Stick to a consistent bedtime routine
  • Try to go to bed at a consistent time
  • Avoid consuming foods, drinks, or medications that contain caffeine or other stimulants prior to bedtime
  • Steer clear of large meals before sleep
  • Avoid partaking in strenuous exercise before sleeping
  • Keep your bedroom dark, quiet, and cool
  • Try to wake up at the same time each day

While SAD is a common and serious disorder, it does not have to rule your life or ruin your sleep. If you suspect you might be struggling with SAD, do not hesitate to reach out to a healthcare professional to get the help you deserve.

As a forward-thinking digital healthcare company, Somnology’s platform of integrated sleep services and monitoring data is designed to inform patients, care providers, healthcare payors and employers alike with actionable information to improve health outcomes. Somnology offers a comprehensive perspective to sleep monitoring and care with the SLaaS® (Sleep Lab as a Service) platform, telemedicine, SomnoRing®, and SomnologyMD mobile app. We have streamlined a typical sleep care experience by delivering the technology and medical insight of a sleep lab directly to users. The patient is at the center of our priorities, as we proactively guide them through their individually-tailored sleep care journey. Learn more from our website or reading further on our blog.