Seasonal affective disorder (SAD) is a mood disorder that is characterized by symptoms that occur at the same time each year, usually during the darker, shorter days of fall and winter. Symptoms can include depression, fatigue, and social withdrawal. While this condition usually resolves within a few months, it can have a serious impact on how a person feels and functions.
It is not uncommon for people to experience seasonal fluctuation in moods. You may have noticed how a gray, rainy day makes you feel gloomy and tired, while a sunny day can leave you feeling cheerful and energized. The longer, sunnier days of summer are often associated with better moods, while the shorter, darker days that begin in late fall often align with an increase in SAD symptoms.
Shorter days combined with the stress of the winter holiday season can make the colder months of the year a trying time for many people. And with mood-boosting sunlight in such short supply, the added stresses of living up to our images of the picture-perfect holiday are just too much.
Insufficient exposure to sunlight has been associated with low levels of melatonin and serotonin, carbohydrate craving, weight gain, and sleep disturbance.
The symptoms of SAD occur cyclically with a return of symptoms each year during the winter months. These symptoms tend to be the typical symptoms of depression, including:
- Increased sleep
- Increased appetite and carbohydrate cravings
- Weight gain
- Interpersonal difficulties (especially rejection sensitivity)
- A heavy, leaden feeling in the arms or legs
Seasonal affective disorder is believed to be caused by a disturbance in the normal circadian rhythm of the body. Sunlight entering through the eyes influences this rhythm. When it’s dark, the pineal gland produces a substance called melatonin which is responsible for the drowsiness we feel each day after dusk. Light entering the eyes at dawn shuts off the production of melatonin.
During the shorter days of winter, when people may rise before dawn or not leave their offices until after sunset, these normal rhythms may become disrupted, producing the symptoms of SAD.
There is also evidence linking SAD to a reduced amount of the neurotransmitter serotonin. Serotonin is the feel-good substance that is increased by antidepressants called selective serotonin reuptake inhibitors (SSRIs).
This decrease in serotonin production may be responsible for many of the symptoms of SAD, such as depression and carbohydrate cravings.
There is no laboratory test for SAD. It is diagnosed based upon a person’s symptom history using criteria set forth by the Diagnostic and Statistical Manual of Mental Disorders (DSM-5). The DSM-5 does not consider SAD to be a separate disorder. Instead, it is a “specifier” of a major depressive episode diagnosis. In order to be diagnosed with SAD a person must, first of all, meet the criteria for a major depressive episode.
At least five of the symptoms listed below must be present most of the time during a two-week period. Further, at least one of the person’s symptoms must be one of the first two items listed. A depressed mood that is due to a medical condition or that is related to the content of a delusion or hallucination that the person is experiencing would not count.
- Feelings of depression
- Loss of interest in things once enjoyed
- Changes in appetite or weight not associated with intentional dietary changes for the purpose of gaining or losing weight
- Sleeping too much or too little
- Psychomotor agitation or retardation
- Fatigue or lost energy
- Feelings of worthlessness or excessive guilt
- Problems with concentration, thought, or decision-making
- Thoughts of death or suicide
Any symptoms which could be better explained by their connection to a medical condition, substance use, or grief would also not count. In addition, a psychotic disorder, such as schizoaffective disorder, would have to be ruled out as a cause for the symptoms.
If these criteria fit, the following criteria would also need to be met to obtain a seasonal pattern specifier:
- A seasonal pattern of onset and cessation in major depressive episodes
- Two major depressive episodes meeting all of the above criteria for the past two years without any episodes of major depression have occurred at other times of the year
- A lifetime pattern of having mainly seasonally-related major depressive episodes
Seasonal affective therapy responds well to treatment. The most commonly used treatments for SAD are:
- Light therapy
Light therapy using a device that gives off bright, white light is considered the best form of treatment for SAD at this time.
In fall 1998, a group of 13 Canadian specialists issued a set of professional consensus guidelines for the treatment of SAD. Among their conclusions:
- The starting “dose” for light therapy using a fluorescent lightbox is 10,000 lux for 30 minutes per day. (Alternatively, lightboxes emitting 2,500 lux require two hours of exposure per day.)
- Light therapy should be started in the early morning, upon awakening, to maximize treatment response.
- Response to light therapy often occurs within one week, but some patients may require up to four weeks to show a response.
- Common side effects of light therapy include headache, eyestrain, nausea, and agitation, but these effects are generally mild and transient or disappear with reducing the dose of light.
According to Dr. Michael Terman, head of the Winter Depression Program at Columbia-Presbyterian University, the consensus in the U.S. is that post-awakening bright light therapy, using a broad-spectrum white light source at 10,000 lux, is the first-line intervention. Drugs should be brought in as adjuvants only if light therapy is insufficient.
Optimum dosing of light is crucial since if done wrong it can produce no improvement, partial improvement, or even worsening of symptoms.The Best Light Therapy Lamps
In a study published in the Archives of General Psychiatry researchers exposed participants with SAD to bright lights that were 10 to 20 times brighter than normal indoor electrical lights. One group was exposed to these lights for approximately one and a half hours in the morning, while a second group was exposed in the evening. The third group received a placebo treatment. The participants who were exposed to the morning bright light treatments experienced full or near-full relief from depression.
Newer research published in the Journal of Nervous and Mental Disease has found that even a single, one-hour light session can rapidly improve symptoms of depression in people with SAD. And morning therapy, specifically, can help to correct any sleep-wake cycle issues contributing to the symptoms.
The effectiveness of Wellbutrin XL for the prevention of SAD episodes was established in three double-blind, placebo-controlled trials in adults with a history of major depressive disorder in fall and winter. Treatment began in the September through November timeframe, prior to the onset of symptoms. Treatment ended the first week of spring.
In these trials, the percentage of patients who were depression-free at the end of treatment was significantly higher for those on Wellbutrin XL than for those on placebo.
For all three studies combined, the overall rate of patients depression-free at the end of treatment was 84% for those on Wellbutrin XL, compared to 72% for those on placebo.
Wellbutrin XL is chemically unrelated to other common antidepressant medications like selective serotonin reuptake inhibitors (SSRIs). In fact, there is no conclusive evidence from randomized trials to support the use of SSRIs in the treatment of SAD.
Cognitive-behavioral therapy (CBT) can also be an effective treatment for SAD, particularly if it is used in conjunction with light therapy and medication. CBT involves identifying negative thought patterns that contribute to symptoms and then replacing these thoughts with more positive ones. Best Online Resources for Depression
Healthy habits and lifestyle choices can also help reduce SAD symptoms. Things that you can do include:
- Getting regular exercise
- Getting enough sleep
- Eating a healthy diet that includes plenty of fruits, vegetables, and protein
Research has found that people with SAD often have low vitamin D levels. Because of this, people with the condition are often encouraged to increase their intake of this vitamin either through diet, exposure to sunshine, or vitamin supplementation. However, research on effectiveness has been mixed. Some studies have suggested that it may be as effective as light therapy, while other studies have found no positive effect of vitamin D on SAD symptoms.
Always talk to your doctor before taking any medication, supplement, or herbal remedy to treat seasonal affective disorder.
Monitor Your Symptoms
Recognizing your tendency to experience seasonal depression can be helpful in aiding your treatment and coping. By knowing the signs, you’ll be able to reach out to your doctor and make lifestyle changes that may help you cope more effectively sooner.
The Center for Environmental Therapeutics (CET), a non-profit organization that provides educational materials about SAD, offers free, downloadable self-assessment questionnaires, as well as interpretation guides, to help you determine if you should seek professional advice.
Among the quizzes available are the AutoPIDS and AutoMEQ. Used together, the AutoPIDS helps you determine whether you have the symptoms of SAD and what your natural bedtime is, and the AutoSIGH tracks your current state of depression.
These tests should not be taken as a firm diagnosis, so be sure to discuss your results with your primary care physician or mental health professional prior to beginning any treatment.
Best Overall: Circadian Optics Lumine at Amazon
“Simple, modern design… filters out 99.9 percent of UV rays.”
Best Budget: Verilux HappyLight Compact Personal at Amazon
“Compact at just 1.5-lbs.”
Best Portable: Circadian Optics Lumos 2.0 at Amazon
“Produces an impressive 10,000 lux.”
Best for SAD: Carex Health Brands Day-Light at Amazon
“Filters out more than 99% of UV rays.”
Best Blue Light: Philips goLITE BLU Energy at Amazon
“Has five light intensity settings.”
Best for Office: Carex Health Brands SunLite at Home Depot
“A lightweight product that you can use while you work.”
Best Alarm Clock: Philips Wake-Up Light at Amazon
“Light therapy lamp and natural sunrise alarm clock.”
Best Floor Lamp: Lavish Home Natural Full Spectrum at Amazon
“A flexible neck that you can adjust to any angle.”
Our Top Picks
Best Overall: Circadian Optics Lumine Light Therapy Lamp
Light therapy lamps are a great option for helping with Seasonal Affective Disorder. Before buying a light therapy lamp, make sure to talk to your doctor. If you’re given the go-ahead, our favorite option is the Circadian Optics Lumine Light Therapy Lamp.
The simple, modern design will fit anywhere in your home. This light has an intensity of 10,000 lux in a pure white color that’s designed to imitate the sun at noon, and it boasts three adjustable brightness settings. It filters out 99.9 percent of UV rays to protect your eyes, and the LED bulbs have an impressive 50,000-hour lifespan, so you won’t need to replace them anytime soon.
Best Budget: Verilux HappyLight Compact Personal, Portable Light Therapy Lamp
High-end light therapy lamps can get quite expensive, but you don’t have to drain your bank account to get some relief from SAD. The Verilux HappyLight Compact Personal, Portable Light Therapy Energy Lamp is a best-selling item, and it costs significantly less than many other products.
The Verilux HappyLight is incredibly compact at just 1.5-lbs, and it produces light at an intensity of 5,000 lux, meaning you may need to sit in front of it for longer. It filters out UV rays to protect your eyes, and it’s easy to take with you to work or other destinations thanks to its compact design.
According to reviewers, this light therapy lamp is bright and effective, especially for its small size. Many write that they feel significantly better during the fall and winter when they sit in front of this light, and you can’t beat the affordable price.
Best Portable: Circadian Optics Lumos 2.0 Light Therapy Lamp
Want a light therapy lamp that you can put in your bag and take with you on the go? Then the Circadian Optics Lumos 2.0 Light Therapy Lamp is just what you’re looking for.
This product measures just 2.25” wide, 3.25” deep, and 11.5” long, making it a compact, highly portable option for those with SAD. The design is adjustable, so it can be angled any way, and it produces an impressive 10,000 lux of pure white light using LED bulbs. The Circadian Optics Lumos 2.0 filters out harmful UV rays, and it has three brightness levels to choose from.
This light therapy lamp gets top marks from reviewers, many of whom say it’s one of the best products they’ve tried. Several note that the Lumos 2.0 has helped ease their seasonal depression and the compact size of this lamp is an added bonus.
Best for SAD: Carex Health Brands Day-Light Classic Therapy Lamp
Seasonal affective disorder is no joke—it can cause loss of energy, difficulty concentrating, excessive fatigue and more unpleasant side effects. To optimally treat this seasonal condition, you need a clinically proven product like the Carex Health Brands Day-Light Classic Plus Bright Light Therapy Lamp.
While on the high-end side, this light therapy lamp meets all the expert criteria for treating SAD. The 12-inch lamp produces 10,000 lux of glare-free white light, filtering out more than 99 percent of UV rays. The height and angle of the light are adjustable, and the whole unit stands on a pedestal. There are two brightness settings to choose from, allowing you to customize your treatment.
Reviewers say this is an excellent therapy lamp for treating SAD, writing that they experienced a noticeable improvement in mood after using it. Some users also note that the light has lasted for several years, so it’s arguably worth the higher price point.5
Best Blue Light: Philips goLITE BLU Energy Light Therapy Lamp
While most light therapy boxes emit white light, there are some people who prefer a blue light, which is supposed to be more energizing. If you’re looking for a blue light therapy lamp, you should consider the well-received Philips goLITE BLU Energy Light Therapy Lamp.
This compact lamp gives off a blue light that’s supposed to be as effective as 10,000 lux white light. It has five light intensity settings to choose from, and it filters out UV rays to protect your eyes.
Overall, reviewers have great things to say about the Philips goLITE BLU, writing that it seems to work just as well as standard white therapy lamps. Many note that the product’s portable design lets them bring it to the office in the winter and that they notice a significant difference in their mood and energy levels after using it.6
Best for Office: Carex Health Brands SunLite Bright Light Therapy Lamp
Sitting in a poorly-lit office building for eight hours a day certainly doesn’t help the winter blues. If you’re looking for a way to get a little extra light in your office, consider the Carex Health Brands SunLite Bright Light Therapy Lamp, a lightweight product that you can use while you work.
The SunLite Bright Light Therapy lamp is best for people with mild to moderate seasonal depression, as it provides 10,000 lux light from its 10-inch surface. The lamp filters out more than 99 percent of UV rays for safety and features “quick-change” bulbs for easy maintenance. It weighs just over 3 lbs, making it easy to transport to your office and back.
Reviewers say the SunLite Bright Light Therapy Lamp is a high-quality product with a durable construction. Several note it improved their SAD symptoms, and it comes at a reasonable price, to boot.7
Best Alarm Clock: Philips Wake-Up Light Alarm Clock
Having trouble getting out of bed in the morning when it’s still dark out? This is a common problem during the winter, and a product like the Philips Wake-Up Light Alarm Clock can help!
This light therapy lamp and natural sunrise alarm clock is designed to improve your sleep and energy levels by waking you up gradually. The light has 20 brightness settings to choose from, and it turns on 30 minutes before your alarm, gradually getting brighter to wake you up gently. The light itself is UV-free, and the alarm clock features five wake-up sounds, FM radio capabilities, snooze, and even settings to help you fall asleep.
Reviewers agree that the Philips Wake-Up Light Alarm Clock does exactly what it claims, waking you up naturally to improve energy levels and banish lethargy. Many also note that the various brightness settings are beneficial, as it lets you customize the light to your preferences.8
Best Floor Lamp: Lavish Home Natural Full Spectrum Sunlight Therapy Floor Lamp
Most light therapy lamps are tabletop designs, so you have to put them on a desk, table, or counter to use. If this is inconvenient to you, you might prefer a floor lamp, such as the Lavish Home Natural Full Spectrum Sunlight Therapy Lamp.
This product approximates natural light, providing bright white illumination that’s perfect for reading or working. The lamp has a flexible neck that you can adjust to any angle, and the product measures 60” tall.
Many people use the product for task lighting, but several note that it seems to improve their winter blues, as well. Overall, it’s a more convenient design than other light therapy lamps, and it comes at an unbeatable price.