Before You Buy a Light Box for Seasonal Affective Disorder

Not all light boxes meet the recommended requirements for treating SAD

What to consider before buying a light box

Verywell / Alex Dos Diaz

There are many light box products on the market that claim to help seasonal affective disorder (SAD), but here is what you should know before you invest in one. Not all light boxes meet the recommended requirements for treating SAD.

What Is Seasonal Affective Disorder?

Seasonal affective disorder (SAD) is a type of depression that's related to changes in seasons. The current formal diagnosis is major depressive disorder with a seasonal pattern. As such, it begins and ends at about the same time every year.

If you're like most people with SAD, your symptoms start in the late fall or early winter and continue through the winter months, sapping your energy and making you feel moody. Less often, SAD causes depression in the spring or early summer.

In either case, symptoms may start out mild and become more severe as the season progresses. Common symptoms of SAD include:

  • Feelings of depression that come and go at the same time each year, usually starting in the fall and winter, but in some cases in the summer
  • A lack of energy; feelings of fatigue and lethargy; sleeping more than usual
  • Increased appetite, sometimes accompanied by weight gain
  • Cravings for high-carb and sugary foods
  • Difficulty focusing and concentrating on normal daily tasks
  • More severe symptoms of premenstrual syndrome (PMS) or premenstrual dysphoric disorder (PMDD)
  • Withdrawing from friends and family
  • Low libido
  • Feelings of anxiety

Don't brush off that yearly feeling as simply a case of the "winter blues" or a seasonal funk that you have to tough out on your own. Take steps to keep your mood and motivation steady throughout the year.

SAD and Major Depression

Seasonal affective disorder is a subtype of major depression that comes and goes based on seasons. So symptoms of major depression may be part of SAD, such as:

  • Feeling depressed most of the day, nearly every day
  • Feeling hopeless or worthless
  • Having low energy
  • Losing interest in activities you once enjoyed
  • Having problems with sleeping
  • Experiencing changes in your appetite or weight
  • Feeling sluggish or agitated
  • Having difficulty concentrating
  • Having thoughts of death or suicide

If you are having suicidal thoughts, contact the National Suicide Prevention Lifeline at 988 for support and assistance from a trained counselor. If you or a loved one are in immediate danger, call 911.

For more mental health resources, see our National Helpline Database.

Types of SAD

There are two different forms of seasonal affective disorder; fall/winter SAD and spring/summer SAD. Symptoms specific to winter-onset SAD, which is sometimes called winter depression, may include feelings of irritability, low energy, social withdrawal, hypersensitivity to rejection, and a heavy feeling in the arms and legs that begin starting the fall and winter months.

Symptoms specific to summer-onset SAD, sometimes called summer depression, may include depression, insomnia, weight loss, poor appetite, and anxiety that begin in the spring and summer months of the year.

Light Therapy

If you are diagnosed with SAD, there are a number of different treatment options. Treatment for SAD may include light therapy (phototherapy), psychotherapy, and medications. Light therapy is helpful for 50% to 80% of people with SAD.

To treat SAD, a light box needs to have a minimum power rating of at least 10,000 lux. This bright light, which is about five to 20 times the amount of normal indoor lighting, has been shown to reduce symptoms of SAD.

In order for light therapy to be effective, you need to use your light box for at least 30 minutes each day. While direct exposure is important, you should avoid looking directly at the light. Instead, try doing something to stay busy and distracted from the light such as reading a book, watching television, or using your computer. The light box is generally used first thing in the morning.

Before You Buy a Light Box

While light boxes are usually safe and effective, they are not regulated or approved by the FDA for treating SAD. There are, however, requirements recommended by the Center for Environmental Therapeutics (CET) for effective light box therapy. Make sure that any unit you purchase meets these specifications.

Talk to Your Doctor First

While you can buy one without a prescription, always talk to your doctor before you begin treatment with a light box. There are some cases in which light therapy may not be advisable, such as if you have bipolar disorder. If you have eye conditions such as eye damage, glaucoma, or cataracts, you should consult with your ophthalmologist before using a light box.

Clinical Testing

The light box that you buy should have data from peer-reviewed clinical trials to back its effectiveness for treating SAD symptoms.

Sufficient Output

When you are seated at a comfortable distance from the light box, it should provide you with 10,000 lux of illumination. Avoid products which missing or unverified specifications.

UV Filters

Fluorescent lamps should have a smooth diffusing screen to filters out harmful ultraviolet (UV) rays. The light box that you choose should emit as little UV light as possible.

Minimize Glare

In order to minimize glare, the light should be projected downward toward the eyes at an angle.

Sufficient Size

A larger light box is better because even small head movements can take the eyes out of the therapeutic range of the light when a smaller light box is used.

Reduce or Prevent Symptoms

In addition to light therapy, there are also steps you can take that might help prevent SAD or minimize the severity of your symptoms:

  • Increase your exposure to light, particularly during the fall and winter months. Increase the lighting in your home if possible, keep your curtains and blinds open to let in light, and spend a little time outside each day.
  • Get regular exercise. Increasing the amount of physical activity you get each day may help relieve some feelings of depression. Going for a walk or jog outside each day may be particularly helpful since it also includes increased sun exposure.
  • Try taking a vitamin D supplement. While research is inconclusive, some evidence suggests that increasing the amount of vitamin D in your diet may help prevent or relieve SAD. Always talk to your doctor before starting on any supplement in order to prevent potential drug interactions with other medications you might be taking.
  • Reduce your caffeine intake. Stick to only drinking caffeinated beverages such as tea, coffee, and soda in the morning. Drinking caffeine later in the day may interfere with your ability to sleep well at night, and poor sleep may exacerbate feelings of depression.

If you have been using light therapy but still have symptoms of SAD, talk to your doctor. You may need different or additional treatments such as medications or psychotherapy to find relief from your seasonal depression.

13 Sources
Verywell Mind uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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Additional Reading

By Nancy Schimelpfening
Nancy Schimelpfening, MS is the administrator for the non-profit depression support group Depression Sanctuary. Nancy has a lifetime of experience with depression, experiencing firsthand how devastating this illness can be.