Seasonal Affective Disorder: It’s More Than Just “Feeling Blue”

How Less Sunlight Can Impact Your Mental Health

Multiple studies show that when people are exposed to less sunlight, they can develop certain mental health issues. It makes sense, as you may experience changes in mood when the days get shorter.

Daylight Savings Time and Sleep

After daylight savings time ends in the fall, the amount of visible sunlight can drop quickly. This affects your circadian rhythm, or internal 24-hour biological clock. If you have SAD, your circadian rhythm is especially sensitive to changes in daylight.

The circadian rhythm influences sleep cycles and hormone release. Sleep is closely tied to mental health. In one study, researchers found that because of sleep disruptions, patients with depressive disorders noticed a change in mood on the day of, or following, the daylight savings time change.

Chemical Imbalances as Seasons Change

When you’re exposed to sunlight, light passes through your eyes and strikes your retina. This creates a signal that travels to your brain, causing it to produce serotonin, a neurotransmitter involved in mood. Deprived of sunlight, you may receive less of this vital chemical messenger.

Research shows that less exposure to sunlight can cause a drop in serotonin, emotional processing, pain processing, sleep, and other important functions. If you struggle with SAD, you may experience symptoms of depression as your serotonin levels decrease.

On the other hand, lack of sunlight increases production of another important chemical: melatonin. Melatonin is a hormone that causes drowsiness. Because melatonin responds to darkness, its production ramps up as daylight decreases. If you have SAD, you may produce too much melatonin. As a result, you can feel tired and irritable.

If you can increase your exposure to sunlight, you may be able to reduce your symptoms of depression. It’s important to discuss your symptoms with your health care provider so they can suggest lifestyle changes and potential treatment options.

The Signs and Symptoms of Seasonal Affective Disorder

Seasonal affective disorder is a specific type of depression related to seasonal changes—recognized as a subtype of major depressive disorder “with a seasonal pattern.” A less severe form of the condition is known as “winter blues.”

Between 1 and 9% of the general population experiences seasonal affective disorder. Even though SAD is usually tied to the arrival of fall and winter, it can be diagnosed regardless of the specific change in season.

SAD that occurs in summer is far less common and has different symptoms that include restlessness, weight loss, and anxiety.

If you struggle with SAD, you may notice your symptoms start around the same time every year and continue until the seasons change again. For example, if you develop seasonal affective disorder every winter, you’ll likely notice symptoms begin to develop during the fall.

Seasonal affective disorder may steal your energy during the winter months. As a result, you may struggle to maintain healthy relationships with family and friends. You may also have a hard time keeping up in school or with obligations at work. Symptoms usually abate when spring and summer roll around.

The symptoms of seasonal affective disorder can vary depending on its severity. It’s important not to simply write off SAD as moodiness, as it can have a severe impact on your overall quality of life.

Some of the most common signs and symptoms of seasonal affective disorder include:

• Regularly feeling “down”
• Having low amounts of energy that make it difficult to complete daily tasks
• A loss of interest in activities that once brought joy and pleasure
• An abrupt change in sleeping habits: sleeping too much or too little
• An abrupt change in eating habits: eating too much or too little
• An overall feeling of sluggishness or agitation
• Having a short temper
• Being irritated by little things more often
• Having trouble concentrating at work or school
• Feeling guilty about things that are in no way your fault

Remember, these symptoms can fluctuate from month to month. If you have SAD, you may even notice your symptoms change from one year to the next.

The Causes of Seasonal Sadness

Seasonal affective disorder has many possible causes. As with other mental health conditions, everyone is different, and symptoms vary from one person to the next.

You’re more likely to develop SAD if you have certain risk factors, including:

• A history of depression: If you already have depression, your symptoms could get worse during winter.
• Family history of SAD: If you have relatives with seasonal affective disorder, you may be more likely to develop the condition.
• Gender: Studies show that women in their reproductive years are two to four times more likely to develop SAD, seemingly linked to female reproductive hormones.
• Location: People who live farther from the equator in northern latitudes are more likely to develop SAD. For example, 9% of people living in Fairbanks, Alaska were estimated to have SAD compared to 1% in Sarasota, Florida.
• Stress: As the seasons change, your obligations may change as well. You may face an increased workload as your company prepares for the holiday rush. You may face social pressure to participate in activities. Your mental health could be affected by these extra demands.

If you’re feeling consistently low and can’t find the motivation to engage in activities you usually enjoy, it’s important to reach out to a mental health professional.

When To Talk to a Health Care Provider

If you believe you have seasonal affective disorder, or any other mental health issue, it’s important to reach out to a trained, licensed health care professional.

If you can’t find one or don’t know where to start, contact your primary care physician. Your doctor can help with your concerns and refer you to a therapist.

How Seasonal Affective Disorder Is Treated

Fortunately, there are several ways to effectively treat seasonal affective disorder. Talk therapy, light therapy, medication, and lifestyle changes all have the potential to get someone feeling normal again.

Talk Therapy

In addition to making an assessment and providing a diagnosis, your therapist may recommend talk therapy for treating seasonal affective disorder.

With talk therapy, you typically meet with your therapist for about an hour each week for several weeks. Your therapist listens to your concerns and offers support. This can go a long way in helping you manage difficult emotions.

Cognitive behavior therapy (CBT) has been shown to be especially effective in treating SAD. CBT challenges unhelpful thoughts that can lead to depression and anxiety. For example, with the help of skills learned with CBT, you can reframe your experiences of low energy during winter months.

Light Therapy

If you’re diagnosed with seasonal affective disorder, your therapist may recommend light therapy. This form of treatment can encourage your body to produce more serotonin, which can improve your mood.

Light therapy involves specially designed lamps or “light boxes” that contain fluorescent lightbulbs. You typically sit in front of a lightbox for 30 to 60 minutes daily, first thing in the morning.

You shouldn’t stare directly into the lightbox, but instead cast your gaze downward as the light shines on your face. You can read, write, and perform other tasks while using light therapy.

Dawn simulation is another effective form of light therapy. Dawn simulators are alarm clocks that use light instead of, or in addition to, sound.

Similar to natural sunrise, a dawn simulator gradually releases light according to a timer. The light reaches your eyes through your translucent eyelids even before you wake.

Many people find dawn simulation easier to stick to than a lightbox regimen because the routine is automatic. Prices of dawn simulators are comparable to therapy lamps.

Medication

Prescription medications, such as selective serotonin reuptake inhibitors (SSRI), can be an important part of a treatment plan for seasonal affective disorder. SSRIs work by increasing serotonin levels in the brain.

Bupropion (Wellbutrin), a norepinephrine-dopamine reuptake inhibitor (NDRI), is the only medication specifically labeled for treating SAD. NDRIs increase levels of serotonin, as well as the neurotransmitters norepinephrine and dopamine.

When considering any of the above treatments, it’s important to talk to your therapist about options that may be best for you.

Lifestyle Changes Can Make a Difference

In addition to professional treatments, certain lifestyle habits can make a noticeable difference in managing symptoms of seasonal affective disorder. These everyday steps can help lift your mood and support overall well-being.

Get Regular Exercise

Exercise releases endorphins that elevate mood and increase energy levels.

When done during the day, physical activity also provides extra exposure to natural sunlight—another factor that can help ease SAD symptoms.

Prioritize Quality Sleep

Sleep and mood are closely linked. Getting enough rest each night helps you wake up feeling more refreshed and emotionally balanced.

If you struggle with sleep, try maintaining a consistent schedule—going to bed and waking up at the same times every day can strengthen your body’s internal clock.

Seek Out Sunlight

If possible, plan time in sunny environments. Even brief exposure to natural light can make a difference, but traveling closer to the equator during the winter can offer a more lasting boost. The additional daylight hours and increased sunlight exposure may help improve mood and energy.

Eat Nourishing Foods

Choosing foods rich in vitamins, minerals, and lean protein supports both physical and emotional health.

A diet centered on whole, nutrient-dense foods may help reduce inflammation and contribute to a steadier, more positive mood.

Stay Connected With Others

Regular contact with family, friends, and supportive communities can provide comfort and perspective. Talking with loved ones—or with a mental health professional—can reduce feelings of isolation and play an important role in improving overall well-being.

How Seasonal Affective Disorder Is Diagnosed

Your physician may conduct a full physical exam. This is important to make sure your mental health concerns aren’t tied to an underlying physical health problem. It’s not unusual for someone with a physical issue to develop a mental health condition if the physical issue adversely impacts their quality of life.

Your physician or mental health professional may order bloodwork, as many underlying medical conditions can look like mental health issues. For example, if you have a low thyroid count, this could present as a mental health problem. If you can treat the physical health problem, your mental health issues may improve as well.

They will also ask you about your symptoms, wanting to know when the symptoms started, the order in which the symptoms appeared, and any changes in your behavior that may have made the symptoms better or worse.

Your health care provider will compare your medical history and the results of your physical exam to a set of diagnostic criteria to see if you should be diagnosed with seasonal affective disorder. They’ll need to have accurate information to help you formulate a treatment plan.

It’s helpful to keep the following points in mind when speaking to your mental health professional:

• Be honest. If you’re not open with your provider, they won’t be able to diagnose you correctly.
• Don’t assume your therapist is trying to look for something wrong with you. They’re simply trying to get an accurate picture of how your symptoms impact your life.
• Don’t assume any question is too small. If you have questions, it’s important for you to receive answers.

It is not unusual to feel down from time to time. If you find you are persistently sad, though, it’s time to reach out to a mental health professional. Your provider can help you develop a strong treatment plan to help manage your symptoms and help you make the most of every day.

Contributors

Christian A. Webb, PhD