Why do people with anxiety need more sun exposure?

A super variable that should not be underestimated: lighting

In high latitudes, people with a condition called seasonal affective disorder experience feelings of anxiety, irritability, sadness, and depression from late fall through winter. Many people suffer from this problem because the farther away from the equator, the shorter the daylight hours in autumn and winter. The lack of light is an important factor causing disorders.

From an evolutionary perspective, it is not difficult to understand that Homo sapiens, like many other organisms, are affected by the day and night effects of the earth's rotation. It can be said that the periodic changes in light are an important variable that has existed since the birth of the earth. It dominates the energy fluctuations of the natural ecology. About 200,000 years ago, when Homo sapiens had just left Africa, adaptation to light changes could be adjusted by skin color.

However, after industrial civilization, on the one hand, lighting technology has changed people's day and night activity arrangements. On the other hand, cities with high-rise buildings and modern aesthetic concepts have given us very few opportunities to adjust to natural light. Especially the popularity of sunscreen among women has completely blocked natural light from parasols and sunscreen. This also seems to confirm why women are more susceptible to insomnia, anxiety, and depression.

Neurotransmitters are closely related to light

Serotonin is synthesized when the human body is exposed to sunlight. The author is: How to ensure sleep quality? As mentioned in the sleep motivation enhancement article, serotonin can inhibit melatonin secretion, and both of them happen to be the most important substances in regulating our sleep. It can be said that without the suppression of serotonin, it is impossible to have a high-quality sleep at night, because one of the driving forces of sleep is to increase the time spent awake.

In addition, among a large class of antidepressant drugs, they are developed based on the "serotonin reabsorption inhibitor" model, because increasing the concentration of serotonin in the brain can effectively fight depression and anxiety. There is also a wave of people who even believe that the neurotransmitter 5-hydroxytryptamine is also synthesized based on light. This view is elaborated in the book "Winter Blues".

In other words, rhythmic natural light affects sleep by regulating the body's intrinsic circadian rhythm, and also helps the human brain synthesize related neurotransmitters. And our sleep, emotions, and nervous system rely on this. So, how important it is for us to bask in the sun!

There is a way to use "light"

Regarding sleep light, I won’t go into details here.

If you are in the rainy season or the long winter at high latitudes, you can try supplementing with fluorescent lamps during the day. In fact, it is enough to ensure 2,500~10,000 lumens exposure for 1-2 hours a day. At night, you don’t need fluorescent lamps. You must use dim yellow lights. I won’t emphasize this again.

The light cycle is actually one of the fundamentals of the human body. If the fundamentals are good, your body will be conducive to the recovery of anxiety and depression.

(The article comes from the "Youlai Psychology" public account, follow it to get more popular science. )