Picture this: The warmth of the sunlight on your face after a long winter. The sunshine peaking through the trees as you sit on your front porch steps. A few quiet moments in nature when you just needed a breath of fresh air. No matter how you slice it, there is an undeniable shift that happens to us when we spend some time in the sun. Even when nothing else has changed, stepping into the sunlight has the power to improve our mood, energy, sleep, and emotional state.
Summer is officially in swing, and the sun is shining. So, let’s explore the connection between sunlight and mental health, and the specific benefits one can reap for their overall well-being.
The science behind sunlight and mental health
Studies consistently show that sunlight exposure can have a meaningful impact on a person’s mental health and well-being. In a study of operating room (OR) nurses, for example, it was found that those receiving some sunlight exposure had more positive mental health outlooks than others—and their mental health status improved as the duration of sunlight exposure increased. Another study, published in 2024, found that daytime light exposure noticeably reduced a person’s risk of depression, psychosis, self-harm, and post-traumatic stress disorder (PTSD).
The question is: Why?
Well, on one hand, sunlight is the main source of humans’ Vitamin D. As cited by medical professionals, more than 90 percent of our Vitamin D comes from natural sunlight exposure. The skin absorbs this vitamin through ultraviolet B-rays, which then spirals into a range of health benefits.
In addition, scientists have found that sunlight activates the pineal gland, a part of the brain that produces serotonin—the body’s “feel good” hormone. This neurotransmitter carries messages between nerve cells and elevates a person’s mood.
And this is just the start. Sunlight also syncs with our body’s biological clock, known as our circadian rhythm, and helps to regulate sleep cycles. When we are exposed to sunlight in the morning, it physiologically tells our brain to stop producing melatonin (the sleepy hormone) and wake up.
It’s worth noting that darkness has the opposite effect, telling our brain it’s time to sleep. The 2024 study cited above points out, therefore, that it’s important to avoid light at night. Between 10pm and 4am, for example, experts recommend avoiding light to prevent activation of our eyes—and to help prevent depression.
Outside of those nighttime hours, however, exposure to natural light can be pivotal. If a person does not see the sun while they are awake, they are more likely to feel fatigued, drowsy, and foggy. They may have a low mood and low motivation, and if this occurs repeatedly, an increased risk of mental health problems like depression and anxiety.
The primary benefits of sunlight on your mental health
Now that the science behind sunlight is clear (as day), let’s review some of the most common benefits of sunlight on your health and well-being.
- Improved mood.
As suggested above, sunlight boosts our brain’s serotonin production. This hormone, in turn, is what helps a person feel good and calm. It also helps to regulate our emotions. Without a steady supply of serotonin, a person is more likely to face negative mental health conditions like depression.
- Boost in energy.
Serotonin also contributes to higher energy in individuals, helping them feel focused. But this isn’t the only hormone at play. Sunlight also triggers a healthy level of cortisol, which allows the body to feel alert and awake. These hormones directly increase the body’s energy production.
- Higher quality of sleep.
People exposed to sunlight regularly are more likely to have consistent, quality sleep. This is a result of our circadian rhythm working in sync with day and night. Morning sunlight, in particular, regulates our internal clock and signals when it’s time to wake up. It also helps keep melatonin production on track at night, when darkness falls, so that individuals can get a deeper, more restorative sleep.
- Stronger immune system.
Sunlight activates Vitamin D as well as disease-fighting white blood cells (T-cells), which improve our immune system function. Vitamin D on its own plays a key role in our immunity to disease and infection, but these white blood cells are activated by sunlight and enable our body to fight things off more quickly. On top of this, natural sunlight has the power to reduce inflammation. While these are not mental health benefits, exactly, there is an indirect role at play: Sunlight keeps our body healthy, reducing the risk of disease and the mental health issues that can stem from it.
- Increased cognitive function.
Researchers believe that daytime light is essential for learning new things—and nighttime is key to retaining them. When we are exposed to daylight, our brains are activated to be more alert and to absorb information. According to a study in mice, constant dim light exposure (rather than a natural cycle of light/darkness) contributed to impairments in learning and memory over time.
- Decreased stress and anxiety.
Sunlight has the ability to reduce feelings of stress and anxiety, even if it’s just a few minutes a day. This is partially due to the serotonin boost that happens in the brain, which tells our body to feel better or good. Sun exposure can also trigger the release of beta-endorphins in the body, which act as the body’s natural pain and stress relievers.
- Reduced symptoms of depression, especially SAD.
A recent study found that when people spend at least one hour in daylight, during the winter, they are more protected against depression symptoms. Another study, published years prior, found that people experiencing seasonal depression (also known as SAD) saw a significant improvement in symptoms when walking outside, in the morning sunlight, for a one-week stretch.
Seasonal affective disorder (SAD) is a form of depression that is triggered by a change in the seasons. Experts believe there is a correlation between this and daylight. Typically, those battling SAD feel depressed during the colder months, when days are much shorter, and improve or recover during the spring and summer, as sunlight hours stretch.
Can lack of sunlight cause depression or other mental health struggles?
After reviewing all the mental health benefits of sunlight, it poses the question: Can a lack of sunlight lead to negative effects? While this is still being studied, experts believe there is a connection. Seasonal affective disorder, as noted above, is one clear example of this: When darkness falls earlier during the winter months, the symptoms of seasonal affective disorder are most stark and evident.
This may have to do with the dip of serotonin levels experienced on dark days, or an increase in the sleep-inducing hormone, melatonin, which can cause the body to feel lethargic if constantly produced.
However, this is not to say that darkness causes depression, or that everyone who experiences a lack of sunlight exposure will have negative health consequences.
How much sun do you need to reap the benefits?
Experts typically recommend between 10 and 30 minutes of natural sunlight per day. For managing symptoms of depression, extending your time outdoors or in the sun – especially in the early morning – can be especially beneficial. Morning sunlight is thought to carry the most benefits, due to its direct effect on your natural sleep cycle.
Of course, the right amount of sunshine will depend on each person. What’s best (and safest) for one person may differ for another, often depending on their skin tone, their location, and the season or time of day. For example, five minutes of sunlight on a warm beach is different than 10 minutes of direct sun exposure during the winter months.
As a result, it’s important to discuss sunlight exposure with your healthcare provider. Your healthcare provider can guide you on how much sunlight is good for you, and how to exercise sun safety. While sunlight and UV-B rays have notable health benefits, they also carry risks of skin damage and skin cancer. For this reason, moderation and discussions with your provider are key.
Finally, it’s worth noting that sunlight is not a cure-all. While sunlight exposure can be an effective, non-pharmacological way of improving your mental health, it is not guaranteed to resolve your symptoms fully. Professional, evidence-based therapy is still recommended for persistent and more severe mental health conditions. However, sunlight can be a great counterpart to any mental health treatment you’re receiving, and a great way to get a quick mood-boost when you’re feeling down.
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If you or a loved one is experiencing symptoms of depression, seasonal affective disorder, or other mental health issues, you may also consider exploring our programs online. Turnbridge is a recognized mental health treatment facility, with evidence-based and holistic therapies that can be personalized to your needs. Contact us at 877-581-1793 to learn more.