Last Updated on January 17, 2025
Winter months are notorious for stealing away the coveted sunshine and daylight hours. After daylight saving time ends and we fall back an hour, the average American experiences a shift from 12-14 hours of daylight to only 8-10 hours. For some, this shift can bring about feelings of sadness, fatigue, and depression. While the melancholy feelings can resemble the general winter blues, if you experience the winter blues year after year, you might be one of the 10 million Americans diagnosed with Seasonal Affective Disorder (SAD).
A little history behind Seasonal Affect Disorder (SAD)
SAD is a type of depression with its own set of symptoms that is most prevalent during the winter months. It can make you feel low-energy, anti-social, and just generally down. In 1984, a team of researchers at the National Institute of Mental Health in Bethesda, MD, began noticing an uptick in Americans who were reporting seasonally depressive feelings. Even some of the researchers noticed this annual influx of depression and began a 30-year journey for answers. The investigation resulted in a Witness Seminar held by the History of Modern Biomedicine Research Group in 2013, which invited expert witnesses, researchers, and scientists to discuss Seasonal Affective Disorder as a diagnosis.
The seminar championed the acceptance and legitimization of SAD as a real diagnosis and something more than just a winter slump. Since the Witness Seminar conference, there has been broad acceptance that many people experience SAD symptoms, resulting in the introduction of SAD as a subset of major depressive disorder in the Diagnostic and Statistical Manual of Mental Disorders (DSM-5).
So, what exactly is SAD?
Seasonal Affective Disorder is often associated with the disruption of circadian rhythms and serotonin levels caused by the time change in the winter months. For most, symptoms start appearing in late fall and ramp up in intensity during December, January, and February.
What is circadian rhythm?
Circadian rhythms are the mental, physical, and behavioral changes that occur within a 24-hour period. They act as our internal clocks. All organisms have a circadian rhythm and are most affected by the light and dark throughout the day. When the time changes seasonally, and we have less light during the day, our circadian rhythms become disrupted, which can cause SAD symptoms. Let’s take a look at some of the bodily functions circadian rhythms affect:
The sleep/wake cycle
The circadian rhythm affects when you feel tired and when you feel alert. A disrupted rhythm can result in a lack of sleep or excessive sleep. Excessive sleep may look like daytime sleepiness despite getting 7-8 hours of sleep each night, frequent napping during daytime hours, or difficulty waking up.
Hormone production
Circadian rhythms affect two notable hormones: melatonin and cortisol. Melatonin is the hormone that regulates sleep-wake cycles. Too much melatonin can make you feel fatigued and low-energy, while too little can make you feel restless. Cortisol is released into the body in pulses and is directly linked to circadian rhythms. When you’re dysregulated, your cortisol levels are inconsistent, leading to metabolic, behavioral, and sleep disruptions.
Digestion
Circadian rhythms affect digestion, appetite, and metabolic functions. Disruption of the digestive system can cause a host of problems, from stomach issues to insomnia and loss of appetite.
Mood
When our circadian rhythms are in flux, our mood can seem erratic or unpredictable, and we can feel low and morose. Studies have shown that disruptions to the circadian rhythm can lead to decreased serotonin levels, which can contribute to feelings of depression and anxiety. Melatonin plays a crucial role in mood stabilization. When melatonin production is disrupted, it can lead to insomnia and further exacerbate mood disturbances.
Cognitive function
The consistency of your circadian rhythm influences your day-to-day functioning. If your circadian rhythm is disrupted, you may experience mental fog, a lack of clarity, and difficulty concentrating.
These are just a few bodily functions our circadian rhythms can impact. You can see how your circadian rhythm can directly affect your emotions and mental well-being.
Serotonin Slump
Our brains rely on inputs to trigger responses. One such input is exposure to sunlight, which triggers the production of serotonin. Serotonin also regulates several bodily functions that are imperative to our well-being. When we lack sun exposure, our bodies slow the production of serotonin, which can lead to disruptions similar to the ones mentioned above.
What are the symptoms of SAD?
There are a wide array of SAD symptoms that vary from person to person. If you find that you experience multiple symptoms for more than two cycles of winter, you may be experiencing symptoms of SAD.
- An increase in sleepiness or drowsiness during the day
- Excessive sleeping or oversleeping
- Lack of interest or pleasure in activities once enjoyed
- Feelings of hopelessness
- Increased appetite and weight gain
- Decreased libido
- Social withdrawal or desire to be reclusive
- Brain fog
- Difficulty making decisions or focusing
- Feelings of irritability and sensitivity
- Headaches, physical pains and aches
Symptoms tend to be “consistent offenders,” appearing around the same time every year and lasting 3-4 months, usually between November and March, before resolving.
SAD vs. Winter blues
While both Seasonal Affective Disorder (SAD) and the winter blues can lead to feelings of sadness and fatigue during the winter months, they are not the same. The winter blues often refer to mild sadness or irritability that many experience as daylight decreases. These feelings can be transient and usually subside with the return of longer daylight hours in the spring.
On the other hand, Seasonal Affective Disorder is a more severe form of depression that can significantly interfere with daily life. The symptoms of SAD are more intense, last longer, and include not only feelings of sadness but also changes in sleep patterns, appetite, and energy levels. Understanding this distinction is crucial for those who may need help from a physician or licensed mental health clinician to treat their symptoms.
Who is at risk for SAD?
While Seasonal Affective Disorder (SAD) can impact anyone, some are at higher risk for showing signs and symptoms of seasonal depression. This includes people who are already diagnosed with a mood disorder, such as major depressive disorder or bipolar disorder, or who may have a history of depression. Those with these diagnoses could develop a seasonal pattern of intensified depressive symptoms during the winter months.
While adolescents can experience SAD, it’s more common in adults over 20, with symptoms usually starting in adulthood. If someone has a family history of depression or SAD, they’re more likely to show symptoms as well. Interestingly, adult women tend to be the group most affected.
Due to sunlight exposure and daylight hours, it is rare for those living close to the equator to show signs of SAD.
Summer Seasonal Affect Disorder
While SAD is more common in the winter months, some people experience SAD symptoms during the late spring and summer months. This is also due to the disruption of circadian rhythms during the longer summer days. Some differences in symptoms for summer SAD are:
- Insomnia and trouble sleeping
- Loss of appetite and weight loss
- Anxiety and restlessness
- Irritability and crossness
There has been an uptick in summer SAD cases in younger generations due to an increase in time spent indoors, which leads to some food for thought!
How you can treat and prevent SAD
Fortunately, there are several effective ways to treat and prevent Seasonal Affective Disorder (SAD). Reduced sunlight and shorter daylight hours can lower vitamin D levels, which may contribute to SAD symptoms. One common method is to take vitamin D supplements during the winter months. Vitamin D is readily available at most drugstores and grocery stores. The recommended dosage for children and adults ages 1-70 is 600 IU (international units). For adults over 70, the dose increases to 800 IU.
Now, let’s explore additional SAD prevention strategies and treatment options.
Self-care
Self-care is the most essential thing you can do for your mental health during the winter months if you’re experiencing SAD symptoms. You can exercise self-care by setting and sticking to a daily routine, maintaining a journal, keeping up with social activities, and maintaining healthy boundaries.
Light therapy
Sitting in front of a light box for 30-45 minutes daily can help regulate the circadian rhythm and normalize bodily functions. Those experiencing SAD often use light therapy in the early mornings to mimic the rising sun, but it can be used as needed. People report a positive association between symptom relief and light therapy use. While you can order light boxes or SAD light lamps online, it’s best to talk with a doctor so they can recommend the best lamp for you.
While most lamps are very similar, some general light boxes are used to treat skin disorders, and you want to ensure you’re investing in the best one for you!
Lifestyle changes
For some, it may be easy to implement extra routines and habits during the winter to help combat SAD symptoms. Lifestyle changes may include increased socialization, extra time outdoors during sunlight hours, consistent sleeping and waking, and adhering to a nutritional diet.
Therapy
Seeking out therapy or counseling while experiencing symptoms of SAD can be an excellent way to help identify and change specific patterns associated with SAD. It can also be a tool used to help build social relationships and routines.
Medication
If you find it difficult to relieve symptoms in other ways, antidepressants can be an option for those struggling with SAD. You will need to speak with your doctor or a psychiatrist for the correct prescription.
You’ll want to share the details of what you’ve been experiencing, how it has been interfering with daily activities (e.g., not going outdoors), and how long you’ve been experiencing the symptoms (e.g., provide context, and whether you notice any patterns), to give the professional a solid starting point.
You can overcome SAD.
Research has shown that standing in the sun for as little as 10 minutes per day in the winter can improve mood, sleep, digestion, and energy levels. Implementing a daily habit such as a quick walk around the block, a meditation on the porch, or sitting in front of a sun-facing window could be all you need to relieve and improve your SAD.
While some may love the winter season, it can be difficult for others. If you resonate with the symptoms of Seasonal Affective Disorder and think you may have it, it’s important to seek professional help and reach out to a medical or mental health professional.
Our In Session Psych therapists are skilled at supporting our clients and their individual needs, including those experiencing depression, anxiety, and Seasonal Affective Disorder. If you’re interested in individual therapy, we are accepting new clients for in-person sessions at our Charlotte, NC office or virtually for residents of NC and SC.