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Seasonal Affective Disorder

Each year, we set our clocks an hour forward for daylight saving time and experience extended sunlight from the second Sunday of March to the first Sunday of November. The first Sunday in November, we set our clocks back an hour; this means we have less daylight in the fall or winter months.

The reduced sunlight in the fall or winter months coincides with some people experiencing depressive symptoms and episodes of depression. I don’t mean to imply that the end of daylight saving time causes depression. However, there seems to be a relationship between reduced daylight and seasonal affective disorder.

What is seasonal affective disorder?

Seasonal affective disorder (SAD) is a form of depression. The symptoms of SAD can significantly affect people’s moods (thinking, feeling, and behavior) and substantially interfere with their functioning socially and occupationally.

In addition, the symptoms can be mild, moderate, or severe. The number of symptoms, the intensity of the symptoms range from minor functional impairment to significant impairment in social and occupational functioning.

The Diagnostic and Statistical Manual of Mental Disorders (DSM-5) does not list SAD as a separate depressive (MDD) disorder. In the DSM-5, SAD is listed as a specifier for recurrent major depressive disorder with seasonal patterns. Meaning the onset of the recurrent depressive episodes occurs at specific times of the year. The recurrent depressive episodes begin in the fall or winter months. The recurrent seasonal pattern can also happen at the beginning of summer. Summer SAD is less common than fall or winter SAD.

The prevalence of SAD varies by geographic location from the equator, age, and gender. The frequency of the disorder increases at higher latitudes, age is a significant predictor, and younger people are at higher risk for winter depressive episodes.

Symptoms of MDD and SAD may include:

  • Depressed mood most of the day or nearly all-day

  • Loss of interest in pleasurable hobbies or activities

  • Weight loss that is not a result of dieting or gaining excess weight

  • Hypersomnia or insomnia

  • Lack of energy most of the day

  • Feeling guilty or worthless or helpless

  • Problems concentrating, remembering details, or making decisions

  • Significant changes to sleep (feeling tired, even after sleeping well, not sleeping enough, sleeping too much)

  • Significant changes in appetite (not eating to overeating)

  • Irritable, easily frustrated, or restless

Fall or Winter SAD Symptoms

  • Overeating

  • Hypersomnia (frequent daytime sleepiness or extended nighttime sleep)

  • Craving for carbs

  • Feeling tired or having low energy

  • Social withdrawal

Spring or Summer SAD Symptoms

  • Insomnia

  • Aggressive behaviors

  • Anxious distress

  • Poor appetite (reduced desire to eat)

  • Weight loss not associated with dieting

Diagnosis of SAD

If you are experiencing depressive symptoms or a depressive episode, consult with your health care provider or mental health professional. They will complete an assessment to determine if you meet the diagnostic criteria for major depressive disorder with a seasonal pattern.

Treatment for SAD

Depression is a treatable disorder. The treatment of SAD may include talk therapy with a mental health professional. According to the American Psychiatric Association, Cognitive Behavior Therapy (CBT) is an effective treatment modality for SAD. The therapist will collaborate with you and use CBT concepts to address your thoughts, feelings, and behaviors to reduce your specific depressive symptoms. Another treatment option is taking antidepressants. Treatment may also be a combination of talk therapy and psychotropic medications. Light therapy also helps to treat SAD.

Interestingly, the depression appears in the fall and characteristically goes into complete or partial remission in the spring.

Practice good self-care. The absence of a mental disorder order does not negate the need for mental health care.

Stay Naturally Curious


American Psychiatric Association (2013). Diagnostic and statistical manual of mental disorders 5th edition.

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