Are you the type of person who tends to feel so much more alive and energetic when the sun is shining brightly outside? Then, you’re in good company. Millions of people are impacted by changes in the weather and are more likely to feel happy when there’s more sunlight.
Last winter, I noticed that I felt pretty down and discouraged. Life felt more overwhelming than usual, and I noticed a general decline in my mood. But as soon as I felt that warm spring sunshine on my face, my mood completely turned around. Of course, I still have some rough days, but I feel optimistic and excited about life for the most part. I became curious about the changes I saw in myself, so I decided to research the link between sunshine and mood. What I found out was really surprising, so I thought I would share it with you!
Why Some People Get Sad in Gloomy Weather
Some people experience seasonal affective disorder each year (also known as SAD). This is a form of depression that typically impacts people only in the winter and fall when there is not as much sunlight.
In an attempt to uncover why this happens, researchers with the National Institute for Mental Health studied the connection between light and mood. What they discovered was astonishing. Beyond the impact of sunlight on vitamin D (which is also known as “The Sunshine Vitamin”), light appears to directly impact the brain in ways that affect mood. Let’s dive deeper into this link between light and the brain.
How Sunshine Impacts Mood
You’re probably aware that rods and cones within the eye respond to light striking the retina. This has been common knowledge for many years. But more recently, researchers have discovered that there is another type of photoreceptor that also responds to light. Intrinsically photosensitive retinal ganglion cells (called ipRGCs for short) are photoreceptors that are not found within cones and rods. They contain a light-sensitive protein called melanopsin.
So, what do ipRGCs have to do with how sunshine impacts mood? I’m glad you asked! The ipRGCs send the brain information about the light they’re exposed to. The brain uses this information to regulate different functions, including circadian rhythms (which refer to the body’s internal biological clock). In addition to this function, ipRGCs also project light information to the brain’s mood-regulating areas (specifically the peri-habenular region, ventromedial prefrontal cortex, and the nucleus accumbens). These areas are all involved in decision-making, reward and emotion.
So, to put things in plain English, ipRGCs provide a direct pathway for light to reach areas of the brain that impact mood. When there is more sunlight, these pathways are more activated and result in an uptick in positive emotions in most people.
Other Ways Sunlight Impacts Mood
In addition to its mood-boosting impact directly on the brain via ipRGCs, there are other ways sunlight impacts mood in a positive way. People generally want to get outside and exercise more in sunny weather, and exercise is a natural mood-booster. It stimulates the production and release of endorphins in the body, which are chemicals that make you feel good.
Sunshine also helps your body produce more vitamin D. I mentioned this briefly earlier, but vitamin D is essential for regulating mood. People who are often depressed have low vitamin D levels. For this reason, doctors often prescribe vitamin D to people with mood disorders such as SAD. Vitamin D also helps support immune function. When you’re feeling healthy and well, you’re less likely to get depressed.
If you’re struggling to maintain a positive mood, try to get out in the sun more and pay attention to how your mood changes. Remember to wear sunscreen to protect yourself from skin damage due to sun exposure!