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Seasonal depression

[ self-diagnosing is not advised – please seek professionals for diagnosis ]


Did you know that being in the sun and being close to nature can increase your serotonin levels? This is why when it’s foggy or rainy, people tend to be more moody or depressed. However, when you see signs of depression only during a specific time of the year, there’s a chance you have seasonal depression. The official term for seasonal depression is ​​seasonal affective disorder, also known as SAD.

In this article, we’ll learn more about the relationship between human neurology and this disorder, the difference between SAD and winter blues – a common term to describe your moodiness during the winter season, as well as the misconceptions behind this disorder.

Neurology behind SAD

There has not been a lot of research done around the neurology behind SAD; however, SAD has always been linked to the biochemical imbalance because winter means shorter days and longer nights. Furthermore, theories suggest that sunlight (or light in general) stimulates a part of the brain called the hypothalamus. The hypothalamus is in control of the autonomic functions of humans, such as your appetite and sleep. The lack of control within the hypothalamus (due to the lack of sunlight) affects the production of serotonin (a “happy” hormone), and can also slow down the body’s circadian rhythms (or so called the internal clock). During the darker and shorter winter days, the body also automatically produces more melatonin, which makes one sleepier and moodier.

SAD VS Winter Blues

The following are the DSM-5 criterias for the diagnoses of SAD:

  • The depressive episodes must occur during specific seasons (i.e., only during winter months or summer months) for at least 2 consecutive years. However, not all people with SAD experience symptoms every year.

  • The episodes must be much more frequent than other depressive episodes experienced (if any) at other times of the year in their lifetime.

Winter blues is just a general term for “feeling sad” and isn’t something that can be mentally diagnosed. They are short-lived, and last only a few days, or a week at most.

Furthermore, although rare, SAD does not necessarily have to happen in the winter. Less than 10% of people experience symptoms of SAD during the summer, with psychologists naming it as reverse SAD, or “summer depression”. There’s not enough research done to fully understand this phenomenon.

Common misconceptions

“Everyone experiences gloominess during the winter. SAD is just an exaggeration.”

Despite the fact that SAD occurs only during specific seasons, it doesn't mean that it’s less serious than depression or other mental illnesses. A common misconception is the intensity of the symptoms. SAD can affect one’s relationships with others and can be as serious and debilitating as physical illnesses.

“SAD only occurs when it’s snowing or when it’s freezing cold” SAD occurs because of the long dark nights and the lack of light – not because of the cold or temperature. People suffering from SAD normally turn to light therapy (also called as phototherapy), where one sits near a light therapy box to expose themself to artificial light, which helps trick their brain into lightening their mood or producing the “happy” hormones.


Researcher: Hailey


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