What is seasonal affective disorder? Symptoms, causes and how to treat it.

With the days getting shorter and colder, some people might want to stay cuddled in bed all day with a book or a TV show. But for others, the change of season could spell a difficult depression.

Seasonal affective disorder is a form of depression that affects about 10 million people in the U.S. If you feel tired, unfocused, inexplicably sad, or generally just not yourself, SAD might be affecting you, too.

The Inquirer spoke to three mental health professionals about SAD, the symptoms, and what are some ways to treat it.

“It’s basically a depression that exists during a certain time of the year,” said Matthew Wintersteen, a clinical psychologist at Thomas Jefferson University. You might be inclined to dismiss it as winter blues, but it’s an actual form of depression, according to the National Institute of Mental Health.

Shorter daylight hours and living in colder places increase the risk of seasonal affective disorder during fall and winter. But it can also happen in spring and summer.

Timing is a key indicator of seasonal affective disorder, said Jason Lewis, director of mood, anxiety, and trauma disorders at the Children’s Hospital of Philadelphia. “Symptoms must be due to the change of season, not due to a seasonally linked stressor, such as the start of school,” he said.

Seasonal affective disorder tends to develop during young adulthood and is more common among women than men. It’s “relatively rare” among children, Lewis said. Teens experiencing seasonal affective disorder may have different symptoms than adults.

Symptoms of depression may be different for everyone.

The difference between depression and sadness is that depression causes some level of impairment, said Wintersteen. If you find yourself isolating, having a hard time being productive at work or school, and struggling with daily tasks, talk to your doctor about whether you may benefit from treatment.

Other possible symptoms include:

During fall and winter: Oversleeping, weight gain, social withdrawal, and overeating can be indicators that you are experiencing SAD. One unique symptom is cravings, especially carbohydrates. “Some people sort of describe it as if you’re kind of getting ready to go to hibernation,” Wintersteen said.

For children: Look for signs of uncharacteristic irritability, sadness, sleepiness or appetite (either wanting to eat more or less often than usual), Lewis said.

“If this has been someone’s experience in previous winters, it’s reasonable to anticipate that it might happen again,” Wintersteen said. According to NIMH, SAD can run in families, and people with eating disorders, ADHD, anxiety, panic disorder, and bipolar disorder can be at a higher risk.

Lewis recommends making sure your child is getting a fair amount of social interaction and physical activity, especially outside. Help them stick to a healthy sleep schedule and provide nutritious meals. And if they continue to struggle, talk to your child’s pediatrician or mental health professional.

Talk to a doctor to develop a treatment plan. Some approaches they may recommend include:

Lewis recommends cognitive behavioral therapy (CBT) as a starting point for treating SAD. “It teaches you ways to think and act differently to help promote positive mood and coping strategies,” he explained.

This one might make you feel a bit like a plant, but it can be as equally effective as therapy to improve SAD symptoms, according to the NIMH.

Light therapy has been around since the ‘80s, and it involves sitting in front of a specialized lamp called a lightbox to “trick” your body into thinking this very bright apparatus is sunlight. Lewis recommends using it for 30-60 minutes daily to improve your mood and decrease SAD symptoms.

Light boxes aren’t regulated by the Food and Drug Administration and don’t require a prescription, but you should always talk to a doctor before buying and using one.

Light boxes may not be beneficial for people with eye illnesses, taking or using topical medications that increase sunlight sensitivity, and people with diabetes.

Look for one that omits at least 10,000 lux (the measurement of a light’s intensity), said Tania Czarnecki, director of Drexel University’s Counseling Center.

The university has VeriLux HappyLights therapy lamps for the students to use.

The box should produce as little UV light as possible. Mayo Clinic recommends choosing a lamp that is specifically designed to treat SAD. Other lamps designed to treat skin conditions may have too much UV light.

People with extreme symptoms may benefit from an antidepressant. Like many medications, antidepressants may have side effects and it may take a few weeks to feel relief. Antidepressants must be prescribed by a doctor.

You may have heard that vitamin D supplements can help improve seasonal depression symptoms. Research has found low levels of vitamin D among people with seasonal depression. But there is little research on whether taking a dietary supplement can improve symptoms, according to NIMH.