As winter turns to spring and spring turns to summer people generally feel better. It certainly is nice in northern regions to shed heavy coats but the increasing amount of sunlight every day has a positive effect on how we feel. The fact of the matter is that lack of sunlight and depression are directly related. Unfortunately, the same relationship exists for suicide which is highly related to depression. What is the reason for the relationship between sunlight, or lack of it, and how we feel?
What Is Seasonal Affective Disorder?
The Mayo Clinic explains season affective disorder (SAD) saying that it is a type of depression that comes and goes with the seasons. Starting in the fall, as the days become shorter and people spend more time indoors, people who suffer from SAD begin to feel moody and have less energy. In the spring and going into summer these feelings and loss of energy resolve at the same time that days lengthen a people spend more time out of doors.
Indications of Seasonal Affective Disorder
Feeling down or sad most of the day, day after day, listless and not having any energy is typical of seasonal affective disorder. A person loses interest in things they usually enjoy. Also a person with SAD finds that they are sleeping longer and longer hours and when they wake up they are still not refreshed, have trouble concentrating, and are troubled by feelings of worthlessness, hopelessness, and guilt. In extreme cases a person questions the value of life and enduring the feelings that are simply brought on by lack of sunlight! They may also have difficulty controlling their weight as they desire more and more junk food high in sugars and carbohydrates.
What Does Sunlight Have to Do With How We Feel?
Humans are biologically tuned to the rhythms of the seasons. The presence of light and especially sunlight has a direct effect on what is called circadian rhythm which the biological “clock” in the body (brain). The presence of absence of light and especially sunlight affect the production of two substances in the brain, melatonin and serotonin. Both of these directly affect how awake we feel and how sleepy we feel. The majority of these effects happen in the hypothalamus where feelings are controlled.
Turning Melatonin On and Off Affects How We Feel
Sunlight drives the hypothalamus to stimulate the centers that reduce melatonin output and lack of sunlight stimulates centers that increase serotonin output. More serotonin in a person’s system tends to make them sleepy and less tends to make them wakeful. The point is that during winter months when there is less sunlight and people in the north spend more time indoors anyway, there is a tendency for people to have increased levels of melatonin and to feel down, sleepy, and even depressed. These effects reverse when there is more sunlight in the summer. Some people with seasonal affective disorder actually feel better if they take use a sunlamp or go to a tanning studio where they expose themselves to light in the same spectrums as natural sunlight. Interestingly, people who have trouble sleeping may find help by taking melatonin pills. Also, people who have too much “screen time” with computers and smartphones often have trouble sleeping as their melatonin levels remain low due to constant light exposure!
Lack of Sunlight and Suicide Risk
Not only is depression directly linked to lack of sunlight but so is the risk of suicide. There are two factors. One is that less sunlight can cause depression in people who are prone to seasonal affective disorder. The other is that people who are depressed anyway often tend to isolate which generally means staying indoors and out of any natural sunlight, thus compounding their problem.
Getting Out of the House and Feeling Better
When a person is down in the dumps, they typically feel better when they get out of their house or apartment, spend time with people, get some exercise, and expose themselves to natural sunlight. While taking a long walk may be important to get the blood pumping, taking that long walk outdoors instead of in the shopping mall may be equally important. Anyone who suffers from seasonal affective disorder should look into phototherapy and if that is not helping seek professional assistance.
