Seasonal Affective Disorder

Dec 9

Written By Dami S

During the fall and winter months, many people start to notice changes in their mood and energy levels. Seasonal Affective Disorder (SAD) is a form of depression and in the DSM-5, it is identified as a subtype of depression and bipolar disorder. SAD often coexists with other psychiatric diagnoses like alcohol use, anxiety, and personality disorders.

SAD is more than the “winter blues". Symptoms can be distressing and overwhelming. About 5% of adults in the U.S. experience SAD and it can last up to 40% of the year.

Causes of SAD

The cause and etiology of SAD is complex and multifactorial. During seaon changes, people experience a shift in their biological clock, or Circadian Rhythm. These disruptions can lead to changes in melatonin and serotonin levels.

Melatonin is a hormone that is involved in regulating the sleep-wake cycle. Darkness stimulates the production of melatonin in preparation for sleep. As the days get shorter and the nights get longer, melatonin production in the body increases which can lead to feeling more tired and generally lethargic.

Symptoms of SAD

Symptoms can range from mild to severe, and include many symptoms similar to major depression like changes in appetite, loss of interest, feelings of guilt or worthlessness, and difficulty concentrating. However, we tend to notice atypical symptoms of depression. These can include:

oversleeping
over-eating
weight gain and increased cravings (specifically for carbohydrates and sweet foods)

People can also experience SAD in the summer time as well, although this is less common. We usually notice these symptoms:

poor appetite
weight loss
insomnia

Treatment of SAD

The good news is that there are many treatment options for SAD!

Light Box Therapy
This particular type of therapy involves sitting in front of a light therapy box that emits a very bright artificial light that mimics natural sunlight (without the harmful UV rays!). The standard protocol suggests administering bright light therapy at an intensity of 10,000 lux for 30 minutes daily, with treatments preferably conducted during the early morning hours. People generally notice an improvement of symptoms in 2-3 weeks.
When done properly, side effects from light therapy are minimal. However, side effects can include headaches, irritability, and eye strain (never look directly into any bright light!). Conducting light therapy late in the day may cause insomnia.
Psychotherapy
Cognitive behavioral therapy (CBT) can provide support in managing symptoms of SAD by addressive maladaptive thought patterns and behaviors that contribute to depression. One study found CBT for SAD (CBT-SAD) to be equally efficacious as light therapy.
Medications
SSRIs (selective serotonin reuptake inhibitors) are often used to treat SAD and can be used as a stand-alone treatment, or in conjunction with light box therapy.
Buproprion (wellbutrin, aplenzin) is an atypical antidepressant, and the only type of medication that is FDA approved to prevent SAD. A Cochrane review from 2019 provided evidence that starting buproprion treatment between September and November (prior to the typical onset of SAD symptoms) resulted in a lower incidence of depression symptoms in the winter months.
Vitamin D Supplementation
The research studying the relationship between Vitamin D levels and SAD is mixed and the efficacy of Vit D as a stand alone treatment for SAD is inconclusive. However, patients may benefit from optimizing their Vitamin D levels in conjunction with other treatment modalities.
Lifestyle Adjustments
Regular exericse, mindfulness-based stress reduction techniques, and eating a well-balanced diet can all help manage stress, improve coping skills, boost serotonin levels, and alleviate symptoms of depression.

While Seasonal Affective Disorder can be distressing, it is treatable. Recognizing the symptoms and seeking help early can help you take control of your mental health. Talk to your doctor about your symptoms and treatment options.

References:

Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition

Melrose, S. (2015). Seasonal affective disorder: an overview of assessment and treatment approaches. Depression research and treatment, 2015.

Munir S, Gunturu S, Abbas M. Seasonal Affective Disorder. [Updated 2024 Apr 20]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK568745/