Why is Getting Sunlight Important for Mental Health?

Those struggling with mental health are often told they “just need to go outside more” or should “get some sun.” While it’s invalidating to assume that sunlight will magically resolve mental health issues, is there any merit to these claims?

It turns out, when combined with other healthy habits, increased exposure to sun can be a useful tool to ease mental illness symptoms.

Why is this the case?

Many mental health disorders are associated with low levels of serotonin, a neurotransmitter in the brain that helps to regulate mood. Sunlight aids the production of this chemical both directly and indirectly. 

The direct pathway occurs when sunlight hits the retinas within the eye. This sends a signal to the brain to up the production of serotonin, increasing mood (Lotker, 2020). 

The indirect pathway is a bit more complicated. You’ve likely heard that sun on the skin triggers the production of vitamin D. This vitamin has important functions such as working with calcium to keep the bones strong. It is also vital to the production of TPH2, an enzyme used during serotonin synthesis. An increase in vitamin D results in more TPH2, leading to more of the mood-boosting neurotransmitter (Huiberts & Smolders, 2021). 

Additionally, sunlight in the morning helps regulate the circadian rhythm. This is the body’s natural clock, which controls wakefulness, hunger, focus, and more. Sunlight when one first wakes up suppresses the production of melatonin, a sleep hormone, during the day and promotes it at night. As fatigue and trouble sleeping are common symptoms of depression and anxiety, this can be an important step in fixing a sleep schedule. 

What happens without sufficient sun?

In colder climates, there’s typically less sunlight for a large portion of the year. Individuals living in these areas may experience a phenomenon called Seasonal Affective Disorder, or SAD. This is a pattern of depressive symptoms that tend to change with the season. Part of the cause tends to be a decrease in daylight, which would lead to a decline in serotonin production. 

Luckily, a few treatments can help. Taking a vitamin D supplement, using an UV lamp, or engaging in talk therapy are sound methods to reduce symptoms of SAD. If you’ve noticed a pattern of worsening mood in the last few seasons, consider booking with one of our counsellors here.