Existential Psychiatry Blog

Shedding Light on Seasonal Affective Disorder: Causes, Symptoms, and Treatment

October 18, 2023
Back to all posts

As the seasons change and the days grow shorter, many people experience shifts in their mood and energy levels. For some, this is simply a natural response to the changing environment. However, for others, these shifts can be much more profound and debilitating. Seasonal affective disorder (SAD) or "seasonal depression" is a mental health condition characterized by mood changes in connection with specific seasons.

Understanding Seasonal Affective Disorder

SAD is considered a major depressive disorder that follows a seasonal pattern. While it's most commonly associated with the fall and winter months, some individuals experience SAD during the spring and summer. The condition typically starts and ends at the same time each year. For the majority of those with SAD, it begins in late fall and improves in the spring or early summer.

The exact cause of SAD is not fully understood, but experts believe it is related to changes in natural light exposure that affect certain biological functions in the body. The reduced exposure to natural sunlight during the fall and winter months appears to play a significant role in the development of SAD.

Hiker in ice cave considering attending Seattle therapy for seasonal affective disorder

Symptoms of Seasonal Affective Disorder

SAD can manifest with a wide range of symptoms, and their severity can vary from person to person. Some of the most common symptoms include:

It's important to note that while SAD follows a seasonal pattern, the symptoms of the condition can be severe and should not be dismissed as just a case of the "winter blues." If you or someone you know is experiencing these symptoms, it is crucial to seek professional help.

Causes of Seasonal Affective Disorder

There is not one specific cause of SAD. It is believed to likely be a combination of factors including:

Diagnosis of Seasonal Affective Disorder

Diagnosing SAD typically involves a thorough evaluation by a mental health professional, such as a psychiatrist or psychologist. The diagnostic process typically includes:

ndividual meeting in an office with their Seattle therapist

Treatment Options for Seasonal Affective Disorder

The good news is that seasonal affective disorder is a treatable condition, and various strategies and therapies have been found effective in managing its symptoms. A treatment plan will take into account the severity of your symptoms, goals, strengths, and preferences. Common treatment options include:

Light Therapy

Light therapy or phototherapy is one of the primary treatments for SAD. It involves exposure to bright, artificial light that mimics natural sunlight. Special light boxes used for daily sessions, typically in the morning, can help regulate the disrupted circadian rhythm associated with SAD.

Dawn Simulators

An alternative for those who find bright light therapy too intense is a dawn simulator. These are devices that gradually increase the intensity of light in the morning to simulate a natural sunrise. Many dawn simulators are part of an alarm clock that can sit on the bedside table. Research has found these devices to be similarly effective to light therapy for those with fall/winter onset SAD. This might be a gentler approach for those who find traditional light therapy too intense.


In cases of severe or persistent SAD, antidepressant medications, particularly selective serotonin reuptake inhibitors (SSRIs), may be prescribed. These medications can help regulate mood and alleviate symptoms. However, they should be used under the guidance of a healthcare professional.


Talk therapy, such as cognitive-behavioral therapy (CBT), can be effective in helping individuals with SAD develop coping strategies to manage their symptoms. CBT can also help address negative thought patterns and behaviors that may exacerbate the condition. When selecting a therapist, look for a professional who is willing to adjust treatment based on your needs and preferences.

You and your provider can discuss each of these options and determine a combination that works best for you.

How to Deal with Seasonal Affective Disorder

Certain lifestyle changes can help manage SAD symptoms in tandem with treatment. Aim to engage in regular physical activity, eat a nutrient-rich diet, and get enough sleep. Prioritize spending quality time with trusted loved ones and when possible, spend time outside in the sunshine. Schedule time to practice mindfulness and relaxation techniques, such as breathing exercises. These are not replacements for treatment but can support your overall well-being as you go through therapy.

Couple walking in snowy woods after attending seasonal affective disorder treatment

Searching for seasonal affective disorder treatment in Seattle?

Existential Psychiatry offers compassionate, comprehensive treatment for SAD in the greater Seattle area and across Washington state. Dr. David Zacharias provides patient-centered and trauma-informed care through diagnostic assessment, therapy, and medication management. Reach out today for a free consultation to decide if Dr. Zacharias is a good fit for you.

Written by Existential Psychiatry Staff


Danilenko KV, Ivanova IA. Dawn Simulation vs. Bright Light in Seasonal Affective Disorder: Treatment Effects and Subjective Preference. Journal of Affective Disorders, July 15, 2015. Accessed October 11, 2023.

"Seasonal Depression (Seasonal Affective Disorder)." Cleveland Clinic, April 10, 2022. Accessed October 10, 2023.