What Is Seasonal Affective Disorder? Combating Seasonal Depression

Medically Reviewed by
Dr. Stacy Henigsman
Nutritionally Reviewed by
Felice Ramallo, RDN

If the question, “what is seasonal affective disorder (also known as seasonal depression), and do I potentially have it?” has crossed your mind, then you’re not alone. The American Psychiatric Association estimates around 5% of US adults have seasonal affective disorder (aka SAD), and the American Family Physician Journal estimates another 10 to 20% of people have a mild form of SAD throughout winter.

By far, the most difficult months for people with this illness in the US tend to be in January and February, when the days are darkest. Though less common, it’s also not unheard of to experience SAD in the summer months (the ‘why’ of which we’ll unpack shortly), and it’s about 4x as common among women as men.

So with that being said: what is seasonal affective disorder, according to psychologists? What are common symptoms? And if you have it (or know someone who suffers from it), what are some ways you can relieve symptoms? Continue reading to learn about the various symptoms and treatments of seasonal depression.

What Is Seasonal Affective Disorder?

Seasonal affective disorder is a type of depression. In the Diagnostic Manual of Mental Disorders, it is categorized under “Major Depressive Disorder with Seasonal Pattern.” It is thought that SAD is brought on by “a biochemical imbalance in the brain,” invoked by shorter daylight hours and less sunlight in winter.

As you might have guessed, SAD is more common the further you get from the equator. For instance, within the contiguous United States, it’s 7x more common in Washington state than in Florida.

So if SAD is associated with less daylight and less sun, then summer SAD isn’t a thing, right? Well, for 10% of people who are diagnosed with SAD, they will get it in reverse from the typical pattern: their depression will be brought on by the increased sun and daylight hours. Some studies indicate these individuals are more likely to live near the equator, and the longer days, in conjunction with increased heat and humidity, are thought to trigger summer SAD symptoms, such as loss of appetite, trouble sleeping, weight loss, and anxiety.  

The takeaway here is that, for at least 5% of Americans, the change of seasons has the power to improve or disrupt their brain chemistry in such a way that they may experience depressive symptoms.

Psychologists don’t fully understand the ins and outs of this mental illness, but more research is being conducted to understand the nuances of why some people experience seasonal affective disorder, and investigate more accessible treatment options for tackling symptoms.

Symptoms of Seasonal Affective Disorder

According to the American Psychiatric Association, common symptoms of SAD include the following:

  • Too much sleep
  • Weight gain (associated with overeating and carbohydrate cravings)
  • Change in appetite
  • Depressed mood (or feeling sad)
  • Loss of interest in favored hobbies or activities
  • Lower energy levels
  • Lowered self esteem
  • Difficulty making decisions
  • Increase in anxious activity (like hand wringing, pacing)
  • Thoughts of death or suicide

Clearly, there is a crossover in symptoms between seasonal affective disorder and depression. It’s important to note that though SAD is a type of depression, it is unique in that it lasts for 4 to 5 months at a time, and is strongly associated with seasonal changes. In fact, SAD is likely to come and go at around the same time every year. Conversely, depression can last all year long, and does not worsen according to seasonal changes.

This does not mean SAD is not as serious as year-round depression. SAD can be very serious. Seasonal affective disorder, like most mental illnesses, has a range of severity from mild to severe.

For someone to be diagnosed with SAD, they often would need to exhibit signs that:

  • Their depression occurs at a similar time each year
  • These depressive episodes are followed by periods without depression

It’s important to note here: if you think you may have any of the SAD symptoms listed above, or you have any reason to believe you have SAD in general, then it is critical you seek professional help.

Treatments for Seasonal Affective Disorder

There are treatments available if you believe you have SAD.

They include the following:

  • Light therapy
  • Antidepressant medications
  • Talk therapy

Let’s briefly touch on each one. Light therapy involves using a light therapy box, which emits a very bright light (while filtering out harmful UV rays) and requires you to sit in front of it for some time each day. Otherwise known as ‘seasonal affective disorder lamps,’ this therapy need not be disruptive to your daily routine: you can use the SAD light box while working at your desk, for 30 minutes in the morning, or before bed.

The American Psychology Association suggests that patients use their light therapy box daily, preferably first thing in the morning, during the winter months. Improvements in mood typically manifest within 1-2 weeks of beginning this type of treatment. For people with SAD to keep seeing results, this is an ongoing treatment: for all of winter, it is recommended patients use their light box. Research on the effectiveness of light therapy is mixed, with some studies showing positive changes in mood, and others demonstrating no effects. Given the relatively small upfront cost, as well as the few side effects, it appears this would be an option well-worth trying for those suffering from winter-induced SAD. Just make sure to get one that filters UV rays, to prevent increased risk of skin cancer.

Another treatment, which can be used in conjunction with seasonal affective disorder lamps or without, would be talk therapy – specifically cognitive behavior therapy. Otherwise known as CBT, this is a type of psychotherapy that shows promise for managing SAD symptoms. For instance, a 2016 randomized trial of 177 participants found that – when compared with light therapy – CBT showed greater long-term effectiveness following acute treatment.

CBT-SAD therapy relies on typical CBT techniques, such as identifying negative thoughts, and replacing them with more positive substitutions. It also includes “behavioral activation” which helps the patient identify activities that are enjoyable and engaging, in order to help cope with the winter months.

Other coping techniques CBT encourages include:

  • Journaling
  • Cognitive restructuring
  • Relaxed breathing
  • Progressive muscle relaxation

If you’d like to learn more about CBT, this resource by Positive Psychology, may be useful for gaining insights into the benefits and limitations of this psychotherapy.

Finally, some doctors and psychiatrists may prescribe antidepressants to help patients cope with SAD. Antidepressants may be most effective if taken in late fall, or early winter, before symptoms appear, and are continued until spring. A type of antidepressant categorized under Selective Serotonin Reuptake Inhibitors, shortened to SSRIs, is the preferred type of antidepressant for treating SAD. It is thought to increase levels of serotonin in your brain, with the overall aim of improving mood.

This isn’t a perfect solution, however. Research on the effectiveness of antidepressants for treating seasonal affective disorder is mixed, although a 2003 paper in the Dialogues of Clinical Neuroscience found 3 double-blind, placebo-controlled trials conducted examining the effectiveness of SSRIs showed promise. It’s important to note that antidepressants have the ability to interact with other medicines, and they can take 4-6 weeks to have an effect on patients. They also have potential side effects, like feeling agitated, shaky, and having an upset stomach.

Seasonal Affective Disorder and PCOS

Seasonal Affective Disorder can affect women with PCOS.

There is little research on whether women with PCOS are at heightened risk for SAD specifically, though. It is well documented that women with PCOS are at heightened risk of experiencing general depression compared to women without PCOS. For instance, research shows between 27% and 50% of women with PCOS report being depressed, while only 19% of women without PCOS report the same.

However, as we have noted, SAD is seasonal, with routine ‘begin’ stages and ‘end’ stages which correlate with the seasons. Fortunately – as of right now – there is not evidence to suggest that women with PCOS experience higher levels of SAD than other women. What we do know, though, is that women in general are more likely to experience SAD than men.

The reason as to why (like with many things SAD-related!) is not entirely understood: some researchers suggest fluctuating estrogen levels affect serotonin production, which makes women more vulnerable to lowered levels of serotonin. Given the impact of hormones on mood, and the frequent imbalance of hormones in women with PCOS, our recommendation would be to pay attention to how you feel with the seasonal changes. Do you find yourself in a lowered mood throughout winter? Do you have little energy for any activities from November to February? Is it common for you to oversleep, overeat, or be overrun with negative thoughts during this time?

If you answer ‘yes’ to any of these questions, especially if there aren’t any other external factors (such as a job loss, bereavement, and so on), then it is worth booking an appointment with a doctor to discuss potential causes.

Disclaimer: if you believe you have symptoms relating to seasonal affective disorder, it is important to get in touch with your primary care physician as soon as possible. They can advise you on diagnosis, symptoms, and treatments.

Allara Health provides personalized treatment that takes the guesswork out of managing PCOS, and offers a customized, holistic plan of attack that merges nutrition, medication. supplementation, and ongoing, expert support to begin healing your body.

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