The vibrant array of reds and oranges filling the trees begin to fade away, and the brisk air of Fall turns to sharp stings of winter wind. The transition between seasons has a bigger effect on students than most people are aware of. Seasonal depression, also known as seasonal affective disorder (SAD), is a mood disorder characterized by depression that occurs at the same time every year and is induced by seasonal changes. 

There are many different causes of seasonal affective disorder besides the shift in weather. 

As winter approaches, days get shorter, the sun rises and sets earlier, and daylight savings ends. All of this contributes to less sunlight, causing students’ biological clocks to shift. Every student has an internal biological clock regulating their hormones, sleep, and eating habits. When it tries to shift with the seasons, it causes inconsistencies in the sleep schedules that students are used to. This can affect them more since their days are on a specific schedule constantly. 

Another big contribution to seasonal depression is the way neurotransmitters send communications between nerves. These chemicals include serotonin, which contributes to feelings of happiness. If a student is at risk of SAD, they may already have less serotonin activity. Since sunlight helps regulate serotonin, a lack of it in the winter can make the situation worse. Serotonin levels can fall further, leading to depression.

Serotonin level also gets a boost from vitamin D. Since sunlight helps produce vitamin D, less sun in the winter can lead to a vitamin D deficiency. That change can affect serotonin levels and overall mood.

Melatonin is a chemical that affects sleeping patterns and mood. The lack of sunlight may stimulate an overproduction of melatonin in some people. This can cause people to feel sluggish and sleepy during the winter.

People with SAD often have stress, anxiety and negative thoughts about the winter. Researchers aren’t sure if these negative thoughts are a cause or effect of seasonal depression.

*All information from the official website of the Cleveland Clinic.