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The end of daylight saving time means shorter days, less sunlight, and for some, an increased risk of seasonal depression. Getty Images
  • Most parts of the United States observe daylight saving time.
  • Many people are prone to seasonal depression during the fall and winter.
  • Research indicates that daylight saving time can increase the symptoms of seasonal depression for some people.

Most parts of the United States observe what’s known as daylight saving time. Each year, beginning on the second Sunday in March, clocks are set 1 hour ahead. Then, on the first Sunday in November, they’re set back an hour to standard time.

Since its adoption by Congress in 1918, there’s been ongoing controversy about daylight saving time. Some argue it reduces energy consumption and improves the economy. Others say there are potential health and safety issues, such as increased risk of heart attacks or traffic accidents.

An emerging concern, however, is its effects on mood disorders, like seasonal depression.

Seasonal depression is a type of mood disorder that primarily occurs at a specific time of the year.

Most commonly, people have seasonal depression during the fall and winter months. There are those, however, who have a form of seasonal depression that occurs during the spring and summer months.

The Diagnostic and Statistical Manual of Mental Disorders (DSM-5) is a handbook mental healthcare providers use to diagnose mental disorders such as seasonal depression.

The DSM-5 name for this condition is “major depressive disorder with a seasonal pattern.” It’s also commonly referred to as seasonal affective disorder (SAD).

According to the DSM-5, seasonal depression includes symptoms such as:

  • feeling sad or depressed
  • losing interest in things previously enjoyed
  • eating more, especially carbohydrates
  • sleeping too much
  • lacking energy or feeling tired
  • feeling either restless or slowed down
  • feeling guilty or worthless
  • having problems with making decisions or concentrating
  • thinking about death or suicide

People with seasonal depression tend to follow the same pattern each year, feeling depressed during the fall and winter (or spring and summer), but feeling well the rest of the year.

If you’ve experienced this pattern for at least 2 years in a row, it’s possible that you may have seasonal depression.

Our bodies have an internal clock, or circadian rhythm, that cycles us through daily periods of sleep and wakefulness.

Our body clock is set based upon our exposure to sunlight. When light enters our eyes, it sends the message to our brain that it’s time to wake up. When it’s dark outside, a hormonal signal is sent to our brain that it’s time to sleep.

During the fall and winter, when the days are shorter, our body clock may become disrupted due to a lack of exposure to sunlight. This can lead to the symptoms we know as seasonal depression.

People who experience seasonal depression are already prone to disturbances in their body clock. It’s thought that time changes could make depression worse by disrupting the body clock even further.

Research seems to suggest this is true. A study published in 2017 found that there was an 11 percent increase in depressive episodes during the switch from daylight saving to standard time.

As to why this occurs, Dr. Jane Timmons-Mitchell, associate clinical professor of psychology in the department of psychiatry at Case Western Reserve University School of Medicine, explained, “It is thought that, when sunset is earlier, it disrupts some of our bodily functions.”

“The circadian rhythm, or the 24-hour cycle that helps us regulate when to sleep, rise, and eat, is thrown off,” she added. “Good functioning for health and mental health relies on a regulation of this process.”

Dr. Hanne Hoffmann, assistant professor of animal science at Michigan State University, said that the ill effects during the spring time change are “primarily caused by lack of sleep causing fatigue. The change in time causes a mismatch between our body’s time-keeping system and the social expectations, such as having to get to work one hour earlier.”

Timmons-Mitchell and Hoffmann offer the following four tips for reducing your risk for seasonal depression:

  1. Begin treatment early. Light therapy can both treat and prevent seasonal depression, says Hoffmann. Start using it before symptoms appear.
  2. If possible, plan to travel to a sunnier location when you’re most prone to depression. Timmons-Mitchell notes that in certain countries like Norway, where seasonal depression is common, people will often travel to sunnier areas, like the French Riviera, as a treatment for seasonal depression.
  3. Get out and walk in the morning sunlight. Hoffmann states that taking at least an hourlong walk in the sun can be a useful alternative to light therapy. (Just make sure you wear sunscreen.)
  4. Don’t be afraid to ask for help if you need it. “Many people experience SAD, and you should not be embarrassed about it or be afraid to talk about it with your friends, family, and your PCP,” Hoffmann said.

It’s normal to sometimes feel down or blue.

However, if you’re feeling low for days at a time and you just can’t seem to find the motivation to do things you normally enjoy, the Mayo Clinic recommends that you seek help from your healthcare provider.

This is especially important if you’re noticing changes in your sleep and appetite, you’re using alcohol to comfort yourself, or you’re having thoughts about suicide.

There are several effective options for treating seasonal depression, including medications, psychotherapy, and light therapy.


According to the National Institute of Mental Health, a type of antidepressant called selective serotonin reuptake inhibitors (SSRIs) can be used for treating seasonal depression.

SSRIs include medications such as fluoxetine (Prozac), sertraline (Zoloft), and citalopram (Celexa).

Another type of medication called bupropion (Wellbutrin) is also Food and Drug Administration approved for treating seasonal depression.


Psychotherapy can also treat seasonal depression. In particular, a type of psychotherapy called cognitive behavioral therapy (CBT) is helpful.

CBT involves helping people recognize their negative thoughts and replace them with more positive ones.

A special adaptation of CBT called CBT-SAD adds a technique called behavioral activation to the usual CBT techniques.

Behavioral activation involves helping people find activities they like that will help them cope better with winter.

Light therapy

Light therapy is another method that can treat seasonal depression.

Light therapy involves sitting in front of a light box each day when you wake up.

Light boxes put out light that mimics what you would ordinarily receive from natural morning sunlight. This resets your body clock, correcting your symptoms.

The light put out by light boxes is much different from ordinary indoor lighting. It’s calibrated to provide you with the correct intensity and frequency of light needed to reset your body clock.

Light boxes are also designed to filter out harmful ultraviolet radiation.