Seasonal Affective Disorder

Written by: Abbey Riendeau, LMHC

It’s that time of year again when it’s dark when you wake up in the morning and it’s often dark on your way home from work. Many people feel “down” or may have the “winter blues” when the days get shorter and the weather gets colder. This makes sense because the sun and vitamin D play a role in our moods and how we feel. But sometimes these mood changes are more serious and can impact how a person feels, thinks, and behaves. Significant changes in mood and behavior with seasonal changes may indicate that a person is experiencing seasonal affective disorder (SAD).

The majority of people who experience SAD will notice an onset of symptoms starting in the late fall or early winter, sometimes around the fall time change. This is known as winter-pattern SAD or winter depression. Other individuals experience these depressive symptoms during the spring and summer months; this is referred to as summer-pattern SAD or summer depression. Summer-pattern SAD is less common but not unheard of.

It is estimated that millions of Americans experience SAD each year, although many may not know that they are suffering from this common disorder. In many cases, SAD begins in young adulthood and can persist into late adulthood if not treated. SAD is more common in women versus men. Since winter-pattern SAD is more common that summer-pattern SAD, individuals living further north may have a higher likelihood of experiencing symptoms. This is due to the shorter daylight hours in the winter in many northern locations, such as New England or Alaska. SAD is also more common in individuals with major depressive disorder and bipolar disorder, especially bipolar II disorder, which involves repeated depressive episodes and hypomanic episodes. Additionally, those experiencing SAD tend to be diagnosed with other mental health disorders, such as attention-deficit/hyperactivity disorder and anxiety disorders.

What are the signs and symptoms of SAD?

SAD is a type of depressive disorder that is characterized by recurrent season patterns of depression with symptoms lasting approximately 4-5 months out of the year. Many of the signs and symptoms of SAD are the same as those associated with major depressive disorder. Some symptoms of SAD differ between winter-pattern and summer-pattern SAD.

Listed below of some of the signs and symptoms of SAD. It’s important to note that an individual with SAD may not experience all of these symptoms.

Depression Symptoms:

  • Persistent sad, anxious, or “empty” mood most of the day, nearly every day for at least 2 weeks.

  • Feelings of hopelessness.

  • Feelings of irritability, frustration, or restlessness.

  • Feelings of guilt, worthlessness, or helplessness.

  • Loss of interest or pleasure in activities.

  • Decreased energy, fatigue, or slowed down movements.

  • Difficulty concentrating, remembering, or making decisions.

  • Changes in sleep, appetite, or unplanned weight changes.

  • Physical aches and pains, headaches, digestive problems that do not appear to have a medical cause and do not go away with treatment.

  • Thoughts of death or suicide or suicide attempts.

Winter-Pattern SAD Additional Symptoms:

  • Oversleeping

  • Overeating, particularly with a craving for carbohydrates, sometimes leading to weight gain.

  • Social withdrawal

Summer-Pattern SAD Additional Symptoms:

  • Trouble sleeping

  • Poor appetite, sometimes leading to weight loss.

  • Restlessness or agitation

  • Anxiety

  • Violent or aggressive behavior

It’s important to note that winter-pattern SAD should not be confused with the “holiday blues,” which are feelings of sadness or anxiety brought on by stressors associated with certain times of the year, such as around Thanksgiving or Christmas. Depression associated with SAD is related to changes in daylight hours rather than the calendar or stressors associated with holidays or predictable seasonal changes in school or work schedules.

SAD is diagnosed by a healthcare professional or mental health professional. If you believe yourself or a loved one are showing symptoms of SAD, please reach out to your healthcare provider or seek consultation from a mental health provider. To meet criteria for SAD, an individual must:

  • Experience symptoms of depression or more specific symptoms of winter or summer-pattern SAD listed above.

  • Experience depressive episodes during specific seasons for at least 2 consecutive years. Of note: not all individuals with SAD will experience symptoms every year.

  • Experience depressive episodes during specific seasons more frequently than depressive episodes experience at other times of the year.

Causes of SAD:

The exact cause of SAD is still unknown. Most current research has been focused on investigating potential causes of winter-pattern SAD because it is more common and often easier to study. More research is needed on summer-pattern SAD and the exact causes. Some studies suggest that individuals with SAD, especially winter-pattern SAD, have reduced levels of serotonin in the brain; Serotonin helps to regulate mood. Research suggests that sunlight affects levels of molecules that help maintain normal levels of serotonin in the brain. The shorter daylight hours during the winter may contribute to decreased serotonin levels.

Vitamin D deficiency may also exacerbate these problems in people with winter-pattern SAD because vitamin D is believed to help promote serotonin activity. Vitamin D is consumed through food and the body produces vitamin D when exposed to sunlight on the skin. Individuals many experience lower levels of vitamin D during the winter due to the reduced daylight hours, further reducing serotonin levels.

Some studies suggest that both forms of SAD are related to altered levels of melatonin– a hormone important for maintaining the normal sleep-wake cycle. Individuals with winter-pattern SAD produce too much melatonin, which can increase sleepiness and lead to oversleeping. In contrast, those with summer-pattern SAD may have reduced melatonin levels, consistent with longer and hotter days, which may worsen sleep quality. More research is needed to determine the exact cause of SAD.

Both serotonin and melatonin help maintain the body’s daily rhythm tied to the day-night cycle. Individuals with SAD may experience disruptions in normal daily rhythms due to changes in serotonin and melatonin levels. This results in difficult adjusting to season changes in day length, contributing to sleep, mood, and behavior changes. 

Treatment:

There are treatments available to help people suffering from SAD. Treatments fall into four main categories and individuals may choose to use one treatment or a combination of treatments to address symptoms. Treatment options include:

  • Light therapy

  • Psychotherapy or talk therapy

  • Antidepressant medication

  • Vitamin D supplementation

Light Therapy:

Light therapy has been a mainstay for treating winter-pattern SAD since the 1980s. This type of therapy aims to expose people with SAD to a bright light to make up for the diminished natural sunlight during the darker months of the year. For this treatment, a person sits in front of a specialized light box everyday for approximately 30-45 minutes. Typically, this is done first thing in the morning from the fall to the spring. The specialized light box is about 20 times brighter than an ordinary indoor light and it filters out the potentially damaging UV lights, making this a safe treatment for most people. Individuals with certain eye disorders or those on certain medications that make their skin sensitive to sunlight may need to seek alternative treatments or utilize light therapy under medical supervision.

Psychotherapy or Talk Therapy:

Participating in psychotherapy (also known as talk therapy) with a qualified mental health professional can help individuals with SAD by teaching them new ways of thinking and behaving and changing habits that may contribute to depression. Cognitive Behavioral Therapy (CBT) is a type of psychotherapy aimed at helping people learn to challenge and change unhelpful thoughts and behaviors to improve anxious or depressive feelings. For example, CBT may help an individual challenge and change thoughts related to the darkness of the winter or the heat of the summer with more positive thoughts. Behavioral Activation is another intervention that assists people in identifying and scheduling pleasant and engaging activities to offset the loss of interest they experience during impacted months. When compared to light therapy, talk therapy was equally as effective. Some studies found that light therapy alleviated symptoms quicker but found that the positive effects of CBT seemed to last longer. 

Antidepressant Medication:

Medications used to treat depression, known as antidepressants, can be effective for SAD when used alone or in combination with talk therapy. Antidepressants work by changing how the brain produces certain chemicals involved in mood. Antidepressants take time to take effect, usually around 4-8 weeks to see an improvement. Some individuals report experiencing relief from sleep, appetite, and concentration symptoms before noticing improvement in mood. It’s important to give medication a chance to take effect before deciding if it is right for you. Like all medications, there are the potential for side effects, so it’s important to talk to your provider before changing or stopping medication.

Vitamin D:

Because many people with winter-pattern SAD have vitamin D deficiency, supplements for vitamin D may help improve symptoms. However, studies on the effectiveness of vitamin D have mixed results. Some studies indicate that supplementation is as effective as light therapy and other studies have shown no effect. Vitamin D supplements are typically taken orally, either in a supplement form or as a liquid additive. Talk to your healthcare provider about adding any dietary supplements to your regime. Vitamin D can interact with some medications.

Prevention:

One silver lining of SAD is that the onset is often very predictable for individuals with a history of the disorder. For this reason, individuals who typically suffer from SAD may benefit from starting treatment regimens before the fall for winter-pattern SAD and before the spring for summer-pattern SAD to proactively reduce depressive symptoms. It may be helpful to discuss a personalized treatment plan with a healthcare professional to help determine the best treatment and timing of treatments for you.

Living with SAD can be debilitating and you should not have to suffer without help. Our therapists at Forensic Insight Group are here to support you and answer any questions you may have. If you are feeling as though you are experiencing any of the symptoms listed above, feel free to reach out to us to schedule an appointment or call 988 for immediate mental health support. Understanding your mood and seasonal changes is important in order for you to receive the help you need. 




Citation:

National Institute of Mental Health. (2020). Seasonal Affective Disorder. Www.nimh.nih.gov; National Institute of Mental Health. https://www.nimh.nih.gov/health/publications/seasonal-affective-disorder


‌