Is Seasonal Affective Disorder (SAD) A Myth?

Medically reviewed by Dr. April Brewer, DBH, LPC
Updated April 18, 2024by BetterHelp Editorial Team

Many people experience distressing mental health symptoms in certain climates or during certain types of weather. Others may feel that changing seasons trigger a disaccord with their environment and mood. Although not its own category in the DSM-5, seasonal affective disorder (SAD) is a recurring major depressive disorder with a seasonal pattern. 

While many people experience symptoms of this affective condition, others may believe it is a myth or should not be considered in treatment. Learning more about SAD and how it might impact you can be beneficial when understanding whether the condition is a "myth." 

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What is seasonal affective disorder?

In the Diagnostic and Statistical Manual, Fifth Edition (DSM-5), seasonal affective disorder (SAD) is a subset of major depressive disorder due to seasonal changes. For many, symptoms begin in autumn and continue throughout winter. Symptoms of seasonal affective disorder are the same as major depressive disorder, including: 

  • Low mood
  • Feeling worthless or hopeless
  • Changes in appetite or weight
  • Changes in sleep patterns 
  • Lack of enjoyment in previously enjoyed activities
  • Difficulty with memory, focus, or cognitive function 
  • Fatigue 
  • Difficulty with self-care 
  • Irritability 

The cause of winter-specific depression may be due to vitamin D deficiency. One study showed a connection between a lack of vitamin D and depressive symptoms. The sun is a significant provider of vitamin D. In areas where winter months are long, or there is heavy cloud cover or rain, individuals might experience symptoms of seasonal depression. 

Although many people experience this type of depression during autumn or winter, some individuals also experience the health condition in response to the summer months. People experiencing this form of seasonal depression may feel irritable, stressed, or depressed in response to heat. It may also be connected to thyroid difficulties. 

Is seasonal depressive disorder a myth?

As modern psychologists further study the human mind, some psychologists have published reports believing that seasonal affective disorder does not exist. For example, Megan Traffanstedt, Sheila Mehta, and Steven LoBello of Auburn University at Montgomery published a study in the journal of Clinical Psychological Science arguing a lack of substantial evidence for a seasonal-based modifier on major depressive disorder.  

The study claims "a cross-sectional US survey of adults completed the Patient Health Questionnaire-8 (PHQ-8) Depression Scale," which is a study "designed to determine if a seasonally related pattern of occurrence of major depress could be demonstrated in a population-based study."

The study questioned 34,294 adults ranging in age from 18 to 99 years. The PHQ-8 asked eight questions about if and how often the participants experienced a particular depressive symptom during the previous two weeks. The results showed that depression levels did not correlate with seasonal changes. Season, the latitude of residence with a season, nor sunlight exposure displayed a significant effect on depression scores.

Lobello, Mehta, and Traffanstedt cited a report by Hansen et al. in 2008, which found no increase in depression symptoms by residents of northern Norway during a two-month dark period of eternal night north of the arctic circle. Nor did the report claim a decrease in mental distress during the polar day of perpetual daylight.

"The idea that depression occurs along with seasonal changes or worsens in winter appears to be a well-entrenched folk theory," the study claims.

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Evidence supporting seasonal affective disorder

Although there may be studies against this condition, many scientists find supporting evidence of seasonal affective disorder (SAD). Steven D. Targum, MD, and Norman Rosenthal, MD, published an article in the journal of Psychiatry where Dr. Rosenthal states, "6% of the US population, primarily in northern climates, is affected by SAD in its most marked form. Another 14% of the adult US population [experiences] a lesser form of seasonal mood changes, known as winter blues." 

The pair also studied Norway's residents, like LoBello, Mehta, and Traffanstedt. However, Targum and Rosenthal found that 14% of Oslo, Norway residents displayed SAD symptoms. For comparison, 4.7% of New York City residents exhibited symptoms of SAD.

"In fact," writes Dr. Rosenthal, "someone may have winter blues while living in southern climates and convert to full-blown SAD if they move to a northern climate." This study shows that geographic locations with more extended periods of constant darkness might cause higher levels of depression as opposed to southern locations with more bright light throughout the year.

In another study, Sue Penckofer, Ph.D., RN, Joanne Kouba, Ph.D., RD, Mary Byrn, BSN, RN, and Carol Estwing Ferrans, Ph.D., RN, FAAN, published an article in Issues in Mental Health Nursing discussing the relationship between vitamin D and depression. Their material cites a study of 29 randomized patients divided into two groups, including 16 with SAD and 13 controls. 

These patients received either one hour or 15 minutes of seasonal affective disorder light therapy each morning for two weeks during winter when SAD is often most prominent. Depressive symptoms significantly decreased in the SAD group receiving one hour of light therapy versus the control group. This study indicates that natural sunlight lamps may benefit those experiencing seasonal winter depression.

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The verdict

While studies may suggest seasonal affective disorder does not exist, most studies support the DSM in labeling it as a subset of depression. 

Dr. Targum and Dr. Rosenthal both found increases in depression during winter months, emphasizing the comparison of Norway versus New York City. Sue Penckofer, Joanne Kouba, Mary Byrn, and Carol Estwing Ferrans discussed patients with SAD reporting fewer symptoms of depression after attending light therapy treatments.

Therefore, while some scientists may argue against the existence of seasonal affective disorder, compelling evidence in much more significant amounts continually supports the presence of the disorder.

Finding support for seasonal affective disorder

There are treatment options for seasonal affective disorder. Light therapy, also known as phototherapy, is a popular treatment method where patients sit near a light therapy box that gives off a bright light, mimicking that of natural outdoor light. Patients may also attend psychotherapy sessions to release unease, anxiety, and depression, which are all often related to seasonal affective disorder.

Antidepressant medications are also an effective treatment for SAD. Selective serotonin reuptake inhibitors (SSRIs) such as Citalopram (Celexa), Escitalopram (Lexapro), Fluoxetine (Prozac), Paroxetine (Paxil), and Sertraline (Zoloft) are common choices for depression symptoms. Doctors may also prescribe vitamin D supplements in prescription amounts to aid in other treatments for a potential mood boost in those experiencing SAD during winter months. 

Additionally, online talk therapy can be beneficial for people with seasonal affective disorder who face barriers to in-person counseling. In this type of counseling, clients can choose between video, phone, or live chat sessions with a licensed therapist and can set a schedule that works for them. Studies show that internet-based treatment modalities can effectively treat symptoms of depression, anxiety, bipolar disorder, and other mental health conditions. If you're interested in trying online counseling, to improve your mental health, consider signing up through a platform like BetterHelp.

Takeaway

Seasonal affective disorder (SAD) seems to remain a viable explanation for feeling down in the winter, when access to natural light becomes more limited. While some scientists claim this type of depression does not exist, many studies prove it can occur, and it remains a subset of depression in the DSM-5. If a person suspects they have SAD but is not sure where to start, counseling may be a productive area to begin.

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