Seasonal Affective Disorder © Dr. Eileen SilvaN.D.

Does winter mean depression, weight gain, and a tired, listless existence for you? The good news is that there are bona fide reasons for these issues, and there is something you can do to overcome them. In fall and winter months, especially January and February, the amount of natural light that you absorb decreases in both intensity and duration each day. These seasonal variations of natural light can contribute to a mood disorder caused by a biochemical imbalance in your hypothalamus (due to the shortening of daylight hours and the lack of sunlight in winter) that causes you to experience depression and causes your biological clock (circadian rhythm) to be out of step with your daily schedule, especially if you are a younger person and especially if you are a woman (70-80% of women suffer from this disorder).

You need at least 20 minutes a day of natural light directly on the retina of your eye without glasses or windows blocking the light. When the retina of your eye absorbs natural light, electrical impulses move along your optic nerve to your brain and your hypothalamus, pineal gland, and pituitary gland. Here your body uses it to activate neurotransmitters that turn on many of your hormonal systems, including the metabolism, reproductive functions, and your internal biological clock.

Due to the diminished hours of daylight and winter weather inhibiting your outdoor activities, your body will produce less Serotonin, a hormone your brain secretes in response to light triggers, which affects your wakefulness and elevated mood. Because of the increased amounts of darkness, your body increases production of Melatonin, a sleep-related hormone secreted by the pineal gland in your brain, which causes your body to feel sleepy and groggy. This is the same hormone that triggers hibernation in mammals.

Symptoms you may experience with seasonal affective disorder include: regularly occurring symptoms of depression in winter with excessive eating, sleeping and weight gain during the fall or winter months, craving for sugary and/or starchy foods, feelings of fatigue and inability to carry out your normal routine, misery, guilt and loss of self-esteem, hopelessness, despair, apathy, irritability and desire to avoid social contact, tension and inability to tolerate stress, decreased interest in sex and physical contact, desire to oversleep and difficulty staying awake. You may also exhibit a weakened immune system in winter with more vulnerability to infections and illnesses.

There are natural ways you can combat this disorder. Eating a reasonable amount of complex carbohydrates (fruits, grains, potatoes, etc.) can provide chemical stimulation your serotonin levels, elevating your mood. Eating a balanced healthy diet helps you fight depression and build up your immune system. To diminish your symptoms of depression and to ward off winter weight gain, take regular outdoor exercise in winter. Both the exercise and an increase in the amount of time that you spend in natural light will contribute to better health and an elevated mood. An hour’s walk in winter sunlight is roughly as effective as sitting two and a half hours under bright artificial light. For mild symptoms, it may help you to spend time outdoors and to arrange your home and workplace to receive more sunlight. Eat lunch or breakfast on the porch, walk to the corner market, walk your dog, and sit by an open window to increase the amount of natural light your body receives.

If you have a more serious case, doctors may prescribe phototherapy or bright light treatments, but this light must be at least ten times brighter than natural domestic lighting and your doctor should monitor this treatment. Tanning beds are not good sources because of harmful UV rays that damage your eyes and skin. By recognizing that you can avoid Seasonal Affective Disorder by making sure you do get your natural sunlight, you may avert the seasonal blues.