Is seasonal affective disorder (SAD) a form of depression?

When the days start getting shorter and darker, you may find yourself shifting into hibernation mode, wishing you could curl up in your bed and stay there. It is normal to experience a bit of these “winter blues,” especially if you live in a colder climate with a shorter duration of daylight. But if your blues do not lift after a few weeks, or you develop other symptoms and your low mood starts to interfere with other areas of your life, you may have a mental condition called seasonal affective disorder.

Seasonal affective disorder, or SAD, is a form of major depressive disorder that has a seasonal pattern. “SAD has many of the same symptoms as clinical depression, but it only occurs during certain times of the year,” says Elizabeth Corvino, a psychiatric nurse practitioner. Most commonly, Corvino says, SAD occurs in the fall and winter months, though some people do experience it in the summer. It is relatively common to be diagnosed with SAD—data suggests the condition affects about 5% of the U.S. population each year.

Distinguishing SAD from standard clinical depression can be confusing. The most important distinction is the seasonal pattern. People with SAD don’t feel depressed most of the year, but they experience a major depressive episode each year with the change in seasons. A depressive episode is a two-week period where someone has depression symptoms most of the day, nearly every day. Common symptoms of a depressive episode include, most notably, a low mood—depressed people often feel persistently sad, hopeless, or irritable. Other symptoms of depression include:

• Feelings of guilt or worthlessness
• Loss of interest or pleasure in normal hobbies or activities
• Lack of energy
• Sluggishness
• Restlessness
• Difficulty concentrating
• Changes in appetite or weight
• Changes in sleep habits
• Thoughts of self-harm or death
• Physical ailments without a clear medical cause

According to the National Institute of Mental Health, SAD can come with some unique symptoms, too. Depression can cause people to sleep and eat less than normal, but depression with a seasonal pattern tends toward overeating and oversleeping. SAD can, as well, stimulate an insatiable urge to eat carbohydrates or even gain a few pounds during the winter months.

If five or more of the symptoms (noted above) are present most days during a two-week period, in the fall or winter, you could have seasonal depression. But to be diagnosed with SAD—or any other type of depression—your symptoms must be great enough to interfere with your life, in meaningful ways. “It is time to seek help from a doctor or therapist when you notice a change in your normal functioning because of your symptoms,” Corvino says.

There is one more differentiator: To be diagnosed as SAD, Corvino says, the depression cannot stem from another yearly occurrence. For example, your job or the holidays may be extra stressful in the wintertime. But if those things are the cause of your depression, and not the change of season itself, you may not have SAD.

The best place to start if you think you have SAD is to speak with a mental health clinician, like a psychiatrist or psychiatric nurse practitioner, who can diagnose you and recommend a treatment plan. If you’re diagnosed with SAD, Corvino says typical depression treatment applies. Your provider may recommend an antidepressant medication for the duration of the winter months each year. Some people with SAD, Corvino says, end up taking an anti-depression medication year round. Your clinician can help you decide what is best for you.

Psychotherapy can help with seasonal depression, too, so your provider might recommend you consult with a therapist. One of the most effective types of therapy for SAD is cognitive behavioral therapy, which focuses on helping you identify thoughts and emotions that could be causing you to feel unwell and implement new habits that help you function from day-to-day, when you would rather curl up in bed for the winter. 

Lifestyle changes can help people with SAD feel better, Corvino says. Some studies link seasonal affective disorder with lack of sunlight exposure. Studies suggest light therapy, or sitting in front of a light box that simulates real sun indoors, can help relieve SAD symptoms. Your clinician can help you decide which light device and how to use it). It can be helpful to spend as much time outside as possible, exercise on a regular basis, and eat a nutritious diet. There’s even evidence that adding more vitamin D to your diet can improve mood in the winter months—fish, orange juice, cereal, oatmeal, and milk are all good options. “Anything you do to improve your overall health can also improve your mental health, including SAD symptoms,” says Corvino.

It may take some time to start feeling better; Corvino says an antidepressant medication can take 6 to 8 weeks to be fully effective. In the meantime, do not hesitate to reach out to your doctor, therapist, or the psychiatrists and nurse practitioners at UpLift for information and support.