Winter’s shorter, darker days often bring out feelings of sadness, lethargy, and fatigue. In many cases, these feelings are symptoms of seasonal affective disorder (SAD), a form of depression triggered by seasonal shifts. 

While the nature of SAD means that symptoms tend to improve as the season changes, the condition should be taken as seriously as any other mental health disorder; untreated symptoms of SAD can interfere with daily life. And since SAD is often a temporary but recurring health concern, making a plan before the seasons change can help reduce the severity of future episodes.

Here’s what to know about seasonal affective disorder and effective treatment options.

What is seasonal affective disorder (SAD)?

Seasonal affective disorder (SAD), also referred to as seasonal depression, is characterized by season-related mood changes and other depressive symptoms. In the majority of cases, SAD symptoms begin during fall and peak during winter. It is also possible to experience the opposite pattern, with symptoms that present during spring or summer.

Since SAD is considered a type of depression rather than a separate mental health disorder, many symptoms overlap with those of major depressive disorder, the clinical term for what we commonly think of as depression. Those symptoms include:

• Loss of interest or pleasure in activities

• Changes in appetite or weight

• Difficulty concentrating

• Disrupted sleep

• Fatigue or low energy

• Feelings of low self-worth, guilt, or hopelessness

• Suicidal thoughts

Symptoms specifically associated with winter-pattern SAD include:

• Oversleeping

• Overeating

• Craving carbohydrates

• Weight gain

• Withdrawal from social activities or a desire to hibernate

Symptoms specifically associated with summer-pattern SAD include:

• Difficulty sleeping

• Decreased appetite and weight loss

• Restlessness or agitation

• Increased anxiety

If you believe you are experiencing symptoms of seasonal depression, speak with your healthcare provider or a mental health specialist for an evaluation and diagnosis.

What causes seasonal depression?

Specific causes of seasonal affective disorder haven’t been identified, but reduced sunlight during winter is likely a significant factor, resulting in the following physiological changes.

• Shifts in circadian rhythms: As seasons change, a shift in your body’s internal clock, or circadian rhythms, can disrupt your sleep and energy levels. This can also disrupt your body’s production of certain chemicals, like the stress hormone cortisol, which can also contribute to feelings of depression.

• Imbalanced melatonin levels: Seasonal changes can also disrupt your levels of melatonin, a hormone that helps regulate your circadian rhythms, sleep patterns, and mood.

• Decreased serotonin levels: Reduced sunlight is linked to decreased serotonin, a chemical in your brain that affects mood.

Who does SAD affect?

SAD is diagnosed in more women than in men, for reasons not entirely understood. It also affects younger adults more frequently than older adults.

Given the correlation between reduced sunlight and symptoms of SAD, the condition is more common among those who live further from the equator in either direction, where there are fewer daylight hours during winter months.

The following factors may also increase your risk of seasonal depression:

• Family history: Many people who experience SAD have a relative with the condition or another type of depression.

• Other depressive disorders: SAD may occur when symptoms of major depression or bipolar disorder intensify with seasonal shifts.

• Decreased levels of vitamin D: It’s common to have less vitamin D during the winter as the result of less sunlight. This may play a role in the development of SAD, as vitamin D can boost serotonin activity. If you aren’t getting enough vitamin D from food or other sources, ask your doctor if you would benefit from taking a supplement.

How to treat seasonal depression

Fortunately, there are many ways to treat symptoms of SAD, including light therapy, medication, and psychotherapy. For many people, a combination of treatment approaches leads to better results. While symptoms tend to naturally resolve as the seasons change, treatment can provide earlier relief.

Light therapy

Light therapy, which consists of daily exposure to bright light to compensate for less daylight, is a frontline treatment option for SAD. In this approach, an individual with SAD will sit in front of a very bright light box for 30 to 45 minutes every day. Treatment typically happens first thing in the morning, but a supplemental evening session may also be necessary in some cases.

Light therapy is safe for most people, as the light boxes filter out harmful UV light. However, it may not be a good fit if you have certain eye diseases or take medication that increases your sensitivity to sunlight.

Never begin light therapy without consulting your provider, and make sure to discuss your options for bright light boxes.

Psychotherapy

Psychotherapy, or talk therapy, is another common treatment option for seasonal depression. Cognitive behavioral therapy (CBT) is considered one of the most effective therapeutic approaches for this condition.

CBT focuses on changing thoughts and behaviors. If you experience SAD, CBT may offer the following benefits:

• Better coping with mood shifts

• Stress management

• Improved sleep

• Increased physical activity

• Reduced social avoidance or withdrawal

• Fewer negative associations with winter

Finding the right therapist can take time. If you have insurance coverage of therapy sessions, check your insurance company’s provider network as a starting point. You can also look through reputable online databases like Psychology Today or the American Psychological Association (APA)’s psychologist locator. Some therapists offer sliding scale fees to make sessions more affordable.

Lifestyle and habit adjustments

Some people with SAD benefit from increased exposure to sunlight, whether it means spending more time outside during daylight hours or working from a space with ample sunlight.

Prioritizing your general health and wellness by staying physically active, eating a nutritious, balanced diet, and getting enough sleep can also ease symptoms. 

Medication

While antidepressants aren’t typically prescribed for SAD alone, medication used to treat major depression or another mood disorder may also improve season-related symptoms. Selective serotonin reuptake inhibitors (SSRIs), a type of antidepressant that regulates serotonin, are particularly effective at treating SAD.

Commonly prescribed SSRIs include:

• Sertraline (Zoloft®)

• Paroxetine (Paxil®)

• Fluoxetine (Prozac®)

• Citalopram (Celexa®)

• Escitalopram (Lexapro®)

Always consult your doctor before stopping an SSRI. In most cases, you will gradually taper to lower doses of the medication before you stop taking it completely. This helps to prevent withdrawal symptoms.

In addition to SSRIs, bupropion (Wellbutrin®), another type of antidepressant, may play a role in the treatment of SAD, as well as supplemental vitamin D.

Though it can be frustrating, finding the right antidepressant can take some trial and error. Even if you don't feel like the medication is working, continue to take it as prescribed so that you can achieve a therapeutic level. If you have been prescribed an SSRI, it may take several weeks to a month to experience your medication’s benefits. If you still have concerns several weeks into treatment, speak with your doctor.

For more on the medications used to treat depression, read A Guide to Commonly Prescribed Antidepressants.

Prevention

If you have experienced SAD previously, a healthcare provider may recommend starting an antidepressant before winter as a preventative measure.

Choose a flexible and reliable pharmacy partner

Maintaining good mental health is easier with a reliable pharmacy on your side. Our pharmacists can answer any questions you may have about your medications, and we offer free, same-day delivery and medication management tools like reminders and auto refills in our app.

To learn more, reach out any time through secure in-app messaging or by phone at 1-800-874-5881.

This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or another qualified health provider with any questions you may have regarding a medical condition.

All third party trademarks (including logos and icons) referenced by Alto Pharmacy remain the property of their respective owners. Unless specifically identified as such, Alto’s use of third party trademarks does not indicate any relationship, sponsorship or endorsement between Alto and the owners of these trademarks.