Shedding light on seasonal affective disorder: A Q&A with Essentia’s Dr. Alexandra Kohlhase

January 22, 2024  By: Caitlin Pallai

woman looking out window

As winter continues to unfold and the days remain dark and cold, it is not uncommon for many of us to feel "down" or have the "winter blues." However, if you've noticed a significant change in your mood — impacting how you feel, think and behave — this may be a sign of something more serious.

Seasonal affective disorder, or SAD, is a type of depression that has a seasonal pattern. Below is a Q&A with Dr. Alexandra Kohlhase, a clinical psychologist at Essentia Health, who answers some of the most common questions about SAD, including the primary symptoms.

What is SAD?

SAD is a specific type of depression that occurs with a change in weather, temperature, length of daylight, etc. Most people experience SAD during the winter.

What are the causes?

Less sunlight and shorter days are thought to be linked to a chemical change in the brain and may, in part, cause SAD.

Who is at risk?

People with family or personal histories of depression are more at risk for any type of depressive disorder, including SAD. Additionally, people in very cold or rainy climates may be more prone to the impact of the seasons on their moods. The amount of daylight has a significant impact on people's moods, so those living in climates with very short days are also more at risk.

What are the symptoms?

As with other types of depression, people should be attuned to the following:

  • A decrease in energy and motivation.
  • An increase in fatigue.
  • Social withdrawal.
  • Lack of interest in activities they previously enjoyed.
  • Suicidal thoughts.
  • Feelings of worthlessness.
  • Increased maladaptive coping skills (e.g. increased substance use).
  • Poor self-care and hygiene (e.g. more difficulty brushing teeth or bathing).
  • A decrease in occupational functioning (e.g. being late to work or calling in sick).
  • Changes in sleeping and eating habits.

How is SAD diagnosed?

In order to most effectively treat SAD, consultation with a professional who can diagnose this disorder is advised; however, many people do self-diagnose when they notice a pattern of notable decline in mood and functioning at certain times of the year. Treatment by a mental health professional is also advised from a safety standpoint, as it is always a good idea to have another set of eyes on an individual who may be at risk for feelings of hopelessness, thoughts of self-harm or suicidal ideation.

How is it treated?

Treatment of SAD is very similar to treatment of other types of depression — antidepressants, psychotherapy and behavioral activation — but additional treatments may be recommended, including the use of a HappyLight and supplements such as Vitamin D.

WATCH: In this video interview, Dr. Kohlhase discusses seasonal affective disorder on North Dakota Today.

If you need help

Improve your emotional, psychological and social well-being by partnering with compassionate mental health care professionals at Essentia Health.

Talk to your primary care provider if any of the following affect your daily life:

  • Feeling sad, anxious, hopeless or guilty.
  • Frequent crying.
  • Lack of motivation or energy.
  • Loss of interest or enjoyment in activities or hobbies.
  • Avoiding spending time with others.
  • Changes in your eating or sleeping habits.
  • Difficulty focusing or making decisions.
  • Compulsive behavior or intrusive thoughts.
  • Agitation, anger or paranoia.
  • Hallucinations.
  • Thoughts of self-harm or suicide.

Your doctor may refer you to a mental health professional for care.

Learn more about Essentia's behavioral and mental health services and how to get help and support a loved one at

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