Seasonal affective disorder (SAD) is depression that happens to a person only at a specific time of year. With SAD, a person becomes depressed in fall or winter, when days are shorter and it gets dark earlier. SAD is brought on by the brain’s response to the seasonal changes in daylight. When the daylight hours grow longer again, the depression lifts.
SAD is also called seasonal depression.
What Are the Signs & Symptoms of SAD?
As with other kinds of depression, a person with SAD may notice any or all of these:
Changes in mood. SAD can cause a mood that’s sad, depressed, or irritable. SAD can make people feel hopeless, discouraged, or worthless. They may cry or get upset more easily.
Negative thinking. A person can become more self-critical, or more sensitive to criticism. They may complain, blame, find fault, or see problems more often than usual.
Lack of enjoyment. People with SAD may lose interest in things they normally like to do. They may lose interest in friends and stop participating in social activities.
Low energy. People may feel tired, low on energy, or lack motivation to do things. To them, everything can seem like it takes too much effort.
Changes in sleep. A person may sleep much more than usual. They may find it especially hard to get up and ready for school or work in early morning hours.
Changes in eating. SAD may bring on cravings for simple carbohydrates (think comfort foods and sugary foods) and the tendency to overeat. Because of this change in eating, SAD can result in weight gain during the winter months.
Trouble concentrating. Like any depression, SAD can make it hard to focus. This can affect schoolwork and grades.
With SAD, a person notices these changes only during the time of year when there are fewer hours of daylight. As the season changes and days become longer again, their depression gets better and their usual energy returns.
What Causes SAD?
Seasonal depression is brought on by the brain’s response to shorter daylight hours. Daylight affects two chemicals in the brain, melatonin and serotonin. These chemicals help regulate a person's sleep–wake cycles, energy, and mood.
Melatonin is linked to sleep. The brain makes more melatonin when it's dark. Higher melatonin levels cause a person to feel sleepy and less energetic. Serotonin is linked to mood and energy. The brain makes more serotonin when a person is exposed to sunlight. Higher levels of serotonin boost feelings of happiness and well-being. Low levels of serotonin lead to depression.
Shorter days and longer hours of darkness in fall and winter may cause higher levels of melatonin and lower levels of serotonin. This creates the biological conditions for depression.
How Is SAD Diagnosed?
Talk to your doctor if you think your child has SAD. Health care providers can diagnose it by asking questions and listening. A health checkup can make sure that symptoms aren't due to another condition.
When symptoms of SAD first start, parents might think that a lack of motivation, energy, and interest are due to a poor attitude. Learning about SAD can help them understand another possible reason for the changes, easing feelings of blame or impatience with their child or teen.
Parents might not know how to bring up their concerns to their child. It's best to be supportive and not judgmental. Try saying something like, "You don't seem like yourself lately — you've been so sad and grouchy and tired, and you don't seem to be having much fun or getting enough sleep. So, I've made an appointment for you to get a checkup. I want to help you to feel better and get back to doing your best and enjoying yourself again."
How Is SAD Treated?
If a child or teen is diagnosed with SAD, the doctor may recommend one or more of these treatments:
More Light Exposure
For many kids and teens with SAD, simply spending more time outside during daylight hours is enough to relieve seasonal depression. Exercising outdoors or taking a daily walk are ways to do this. Full-spectrum (daylight) bulbs that fit in regular lamps can help bring a bit more daylight into winter months and might help with mild symptoms.
Light Therapy (Phototherapy)
More troublesome symptoms may be treated with a stronger light that simulates daylight. A special lightbox or panel is placed on a tabletop or desk, and the person sits in front of it briefly every day (45 minutes or so, usually in the morning) with eyes open, glancing — not staring — occasionally at the light. Symptoms tend to improve within a few days or weeks. Even after they feel better, people who use a light therapy box for SAD continue to use it until enough sunlight is available outdoors.
Like any medical treatment, light therapy should be used only after talking about it with a doctor. Carefully follow the instructions that come with the light box.
Talking with a therapist helps relieve the negative thoughts and feelings associated with depression. It can ease the isolation or loneliness that kids and teens with depression often feel. It can help them understand their condition, and learn what to do to prevent future bouts of seasonal depression.
Doctors may prescribe medicine for some kids and teens with SAD. Antidepressant medicines help balance serotonin and other neurotransmitters that affect mood and energy.
How Can Parents Help?
If your child or teen is diagnosed with SAD, there are things you can do to help:
Participate in your child's treatment. Ask the doctor how you can best help your child.
Help your child understand SAD. Learn about the disorder and provide simple explanations. Remember, staying focused might be hard, so it's unlikely your child will want to read or study much about SAD — if so, just recap the main points.
Encourage your child to get plenty of exercise and to spend time outdoors. Take a daily walk together.
Find quality time. Spend a little extra time with your child — nothing special, just something low-key that doesn't require much energy. Watch a movie or share a snack together. Your company and caring are important and provide personal contact and a sense of connection.
Be patient. Don't expect symptoms to ease right away. Remember that low motivation, low energy, and low mood are part of SAD.
Help with homework. You may temporarily need to help your child organize assignments or do work. Explain that concentration problems are part of SAD and that things will get better. Kids and teens with SAD may not realize this and worry that they can't do the schoolwork. You may also want to talk to the teachers and ask for extra time to do homework until things get better with treatment.
Help your child to eat right. Encourage your child to avoid loading up on simple carbs and sugary snacks. Provide plenty of whole grains, vegetables, and fruits.
Establish a sleep routine. Encourage your child to stick to a regular bedtime every day to get the mental health benefits of daytime light.
Take it seriously. Don't put off a doctor visit if you think your child has SAD. If diagnosed with SAD, your child should learn about the seasonal pattern of the depression. Talk often about what's happening, and reassure your child that things will get better, even though that may seem hard right now.