What Is Seasonal Affective Disorder (SAD)?

If you live in a part of the world that has drastic changes in seasonal weather, you may be familiar with the emotional changes that can come from getting less sunlight. Getting less sunlight in Winter may cause people to experience seasonal affective disorder, or SAD. This refers to a type of depression caused by the change of seasons. Decreased daily sunlight is also linked to vitamin D deficiency, which can also contribute to decreased mood during the colder months. In this blog post, we discuss what seasonal affective disorder is and what you can do to stay well during the fall and winter seasons. 

What Is Seasonal Affective Disorder?

Seasonal affective disorder is a type of major depression that recurs seasonally. People typically experience seasonal affective disorder during the fall and winter months, but it is possible for individuals to experience seasonal affective disorder during the summer. During this time, people get less vitamin D from the sun as daily sunlight decreases and may have increased melatonin levels as days are shorter and darker. Increased melatonin levels may cause people to feel sleepy, as this hormone is involved in regulating our sleep cycles. People with seasonal affective disorder also have difficulty regulating serotonin levels, which is needed for mood stabilization. 

What Can I Do If I Have Seasonal Affective Disorder?

There are a number of ways people living with seasonal affective disorder can make the colder months more pleasant. One thing people with seasonal affective disorder who live in the northern hemisphere may do is take a vitamin D supplement, which may help with mood. In addition to supplementing vitamin D, people may use light therapy, which involves sitting in front of a lamp that emits light similar to the sun. Lastly, people may seek psychotherapy or counselling services to help them learn strategies to combat depressive mood during the change of seasons. 


Seasonal affective disorder is a type of major depression that occurs seasonally during the fall and winter months in the northern hemisphere. People with seasonal affective disorder may have decreased vitamin D levels, increased melatonin, and decreased serotonin, which causes them to experience depression symptoms. Seasonal affective disorder is manageable, as individuals living with seasonal affective disorder may take vitamin D supplements, use light therapy, and seek psychotherapy or counseling services to help manage their depressive symptoms and learn strategies to combat depression. Having seasonal affective disorder is normal, and nothing to be ashamed of experiencing. If you or your client is experiencing seasonal affective disorder, make sure that you make time to get outside, get enough vitamin D, and get regular and adequate sleep

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

Dustin was HappyNeuron's Product Specialist. With research experience in stroke, Dustin learned how a stroke can change someone's life. He also learned how different kinds of therapists can work together to help a person get better. He is passionate about neuro-rehabilitation and finding the active ingredients for effective therapy.

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